Dexcool
Thread Starter
Registered User
Joined: Nov 2008
Posts: 670
From: Glendale, AZ
Dexcool
Have a '97 LSS with the 3.8 V-6. I know the owner's manual says to use only Dexcool, but have also had to re-seal the intake manifold a couple of times. Will Prestone work on this car or cause serious damage?
Proud Viet Nam Veteran
Joined: Dec 2006
Posts: 10,817
From: Rowlett, TX
If that is what the owners manual says, I would not run anything else. I run a 50/50 mixture of Dexcool and distilled water in my 94 Corvette. I don't buy the 50/50 mixture they sell. I find buying a gallon of Dexcool and a gallon of distilled water is cheaper. The one thing you never want to do is mix Dexcool and regular antifreeze, It is my understanding it will really clog up you cooling system. If you change, make sure you really flush your cooling system thoroughly.
Registered User
Joined: Aug 2006
Posts: 3,145
From: Far Northeast Philadelphia, PA
Dexcool actully really sucks.
The problem with it is it breaks down very quickly, long before the 150,000 mile life it claims to have. I'm going thru my 2nd set of lower intake manifold gaskets on my Alero and I got the good Fel-Pro ones, the 3rd gen metal gaskets.
My Alero is getting switched over to the green stuff when the mani gasket gets done. Guys have been running it on Aleromod for years with no problems at all, some guys claim the car runs a bit cooler after the switch, but I think it's more like the Dexcool crap gunks up and sticks in some parts of the cooling system. Sometimes I'll be driving along on a hot day and the temp will jump up, and then jump back down. That would be OK if it didn't do it in the winter too.
You have to flush out all the Dexcool before even thinking about the green stuff. They don't mix well at all. When the 2 mix it becomes like a geltain thick goopy stuff and we know what will happen next.
A guy on Aleromod has a L67 in his Alero, pushing 300 horse and he's running the green stuff. The 3800 s/c motor you have is pretty popular. I would look into a another board like this that is just for your car, or sister car, and see what they say.
IDK which one's the best, but there is the following for the Grand Prix:
www.grandprixforums.net/ - 56
http://clubgp.com
www.grandprix.net
The problem with it is it breaks down very quickly, long before the 150,000 mile life it claims to have. I'm going thru my 2nd set of lower intake manifold gaskets on my Alero and I got the good Fel-Pro ones, the 3rd gen metal gaskets.
My Alero is getting switched over to the green stuff when the mani gasket gets done. Guys have been running it on Aleromod for years with no problems at all, some guys claim the car runs a bit cooler after the switch, but I think it's more like the Dexcool crap gunks up and sticks in some parts of the cooling system. Sometimes I'll be driving along on a hot day and the temp will jump up, and then jump back down. That would be OK if it didn't do it in the winter too.
You have to flush out all the Dexcool before even thinking about the green stuff. They don't mix well at all. When the 2 mix it becomes like a geltain thick goopy stuff and we know what will happen next.
A guy on Aleromod has a L67 in his Alero, pushing 300 horse and he's running the green stuff. The 3800 s/c motor you have is pretty popular. I would look into a another board like this that is just for your car, or sister car, and see what they say.
IDK which one's the best, but there is the following for the Grand Prix:
www.grandprixforums.net/ - 56
http://clubgp.com
www.grandprix.net
Antifreeze
Registered User
Joined: Apr 2009
Posts: 43
Wife's 2002 Olds Silhouette has the DexCool sludge monster. Here is a supposed TSB nabbed from the web.
(...It's long, but useful.)
- Ken
**Continued**
(...It's long, but useful.)
- Ken
Theres actually a TSB issued on the DexCool by GM. The sludge is really internal rust in the cooling system due to air pockets.
Pulled up a rather GM generic TSB....you may be able to get an idea of whats up...
Rust in Cooling System, Heater Inoperative, Blows Cold Air, Engine Overheats (Flush Cooling System) #99-06-02-012D
Rust in Cooling System, Heater Inoperative, Blows Cold Air, Engine Overheats (Flush Cooling System)
1996-2000 Chevrolet and GMC S/T Models (Blazer, Jimmy, Sonoma, S10 Pickup)
1998-2000 GMC Envoy
1996-2000 Oldsmobile Bravada
with 4.3L V6 Engine (VINs W, X -- RPOs L35, LF6)
This bulletin is being revised to include additional model years. Please discard Corporate Bulletin Number 99-06-02-012C (Section 06 -- Engine).
Condition
Some customers may comment that the heater is inoperative, blows cold air, engine may exhibit an overheat condition or the coolant reservoir has rust in it.
Cause
Vehicles equipped with DEX-COOL® coolant, which may have been operated for extended periods of time with a low coolant level, usually in excess of 32,000 km (20,000 mi), may be susceptible to the formation of a rust-like material in the cooling system.
Correction
Flush the cooling system using the repair procedures that follow.
Parts and equipment required/suggested for this correction are listed below.
1 each *Prestone® Flush and Fill Kit #AF-KITP U.S. (#00050 in Canada). This kit can be obtained from your local parts supplier and can be used on all vehicles repaired under this procedure. Save it after performing the repair, as it is reusable.
1 each *Prestone® Heavy Duty Cooling System Cleaner, GM P/N 12346500 - 1 per vehicle. This cleaner is in powder form and contains a neutralizer. Do not substitute other cleaners. The diluted cleaners that are available in liquid form are not recommended for this repair.
5.7 L (6 qt) of 100% (non-diluted) DEX-COOL® coolant (GM Spec 6277M).
1 each new thermostat, GM P/N 12563335.
2 each new radiator cap, GM P/N 15075565.
1 each *Prestone® yellow funnel. This funnel can also be obtained from your local parts supplier. It fits snugly into the radiator opening for an easy fill and is reusable.
*We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such items which may be available from other sources.
Important
Verify the fuel level in the fuel tank. The fuel level should be above ¼ tank before this procedure is started.
As a precaution, verify the oil level in the crankcase. Add the amount required to bring the oil level into the normal range.
It is recommended the vehicle be placed in a position so that the following are available:
A sanitary sewer -- not a storm drain, etc
A monoxivent system (if the outside temperature is less than 10°C (50°F)).
Hot running water
Notice
Due to the complexity of these procedures, the following repair steps must be strictly adhered to in order to achieve the intended results. Any deviation or substitution may result in sub-standard cleaning/flushing results or system damage.
Diagnostic Procedure
Install the Scan Tool. This will allow monitoring of the coolant temperature throughout the procedure.
Caution
As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the radiator cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap. Under some conditions, the engine coolant is combustible.
Important
The installation of a NEW radiator cap at the beginning of this procedure and the second new cap at the end of the repair procedure is necessary in order for the correct pressure to be achieved and for the repair to be completed successfully.
The radiator cap is NOT a good indicator of the general condition of the cooling system. Typically the underside of the radiator cap will exhibit a greater amount of contamination than the rest of the system. It is important to evaluate the condition of the cooling system by checking the following before beginning the repair procedure:
Remove the radiator cap. Install a new radiator cap, GM P/N 15075565. A properly operating radiator cap is essential for this procedure to work properly. Be sure to wipe off all radiator cap sealing surfaces prior to installation.
Start the engine.
Using a flashlight or lead light, look into the radiator. From the right side of the vehicle, peer into the radiator toward the left side of the vehicle. Observe the top three rows (or tubes) of the radiator. (It may be necessary to drain off some of the coolant to see the top three rows of the radiator). If it appears the coolant is able to flow through the third row down from the top, the vehicle should be repaired using Procedure A. If it appears the coolant is NOT able to flow through the third row down from the top, then the vehicle should be repaired using Procedure B.
Stop the engine.
Repair Procedure A & B
Important
If available, use coolant exchanger Pro-Fill 42-75100-KM, Power Flush 211-07601/DEX (available through the GM Dealer Equipment program), or equivalent to evacuate the system of coolant. Follow the manufacturer's instructions for exchanging used coolant with new coolant. However, for this procedure, use water in place of new coolant. Be sure to exchange 1½ times the cooling system capacity of the vehicle with water. This will ensure that only water remains within the cooling system. Once the coolant has been displaced with water, drain the water from the radiator.
If you are located within an area which regulates the disposal of used coolant (check with your local water treatment facility), all coolant and coolant/water mixture must be captured until the water runs clear of coolant. Use a clean 208 L (55 gal) drum or similar to contain the waste coolant. Refer to Corporate Bulletin Number 00-06-02-006 for information on coolant recycling and removal services.
Drain and properly dispose of the coolant.
Caution
Any obstructions in the hoses to or from the coolant recovery bottle may cause over-pressurization of the cooling system. This over-pressurization could result in serious personal injury.
Inspect the following hoses in order to assure there are no obstructions and the coolant is able to flow freely:
The hose to the coolant recovery bottle.
The relief hose from the coolant recovery bottle.
Disconnect both coolant hoses to the heater core from the engine.
Back flush the heater core for 5 minutes after clear water is present. Pressurized water not to exceed 345 Kpa (50 psi), may be used.
Reinstall the heater return hose to the engine.
Install the radiator cap and properly tighten.
Install the "T" from the flush and fill kit to a 25.4 cm (10 in) piece of 19 mm (¾ in) heater hose. Tighten the clamp.
Install the hose to the engine. Tighten the clamp.
Install the other end of the "T" in the heater core inlet hose. Tighten the clamp.
Disconnect the upper radiator hose from the radiator. Properly position the hose, so the accessory drive belt or any pulley/belt cannot touch the hose.
If you used coolant exchange equipment, disconnect it.
Attach a garden hose to the "T" of the flush and fill kit. Turn on the water and back flush the cooling system for at least two minutes after the water runs clear.
Start the engine and continue back flushing the cooling system for five additional minutes.
Turn the engine "OFF".
Turn the water "OFF".
Re-attach the upper radiator hose to the radiator.
Open the radiator drain and drain all water from the radiator.
Remove the lower left water pump crossover bolt. This allows lowering the water level in the left side of the engine.
After the water stops running from the water pump bolt hole, reinstall the bolt.
Close the radiator drain.
Mix the Prestone® Heavy Duty Cooling System Cleaner, GM P/N 12346500, in approximately 3 L (3 qt) of warm water. Pour the mixture into the radiator. Top off the system with plain water and reinstall the radiator cap.
Run the engine at 1600 to 1800 RPM with the air conditioning in the maximum cool position. To achieve the 1600 to 1800 RPM, place a dime between the closed throttle stop and the screw. This screw should never be adjusted, under any circumstance. Its only purpose is to keep the throttle plate from sticking in the bore when the throttle is slammed shut. It is not a minimum idle (RPM) control adjustment screw.
Pulled up a rather GM generic TSB....you may be able to get an idea of whats up...
Rust in Cooling System, Heater Inoperative, Blows Cold Air, Engine Overheats (Flush Cooling System) #99-06-02-012D
Rust in Cooling System, Heater Inoperative, Blows Cold Air, Engine Overheats (Flush Cooling System)
1996-2000 Chevrolet and GMC S/T Models (Blazer, Jimmy, Sonoma, S10 Pickup)
1998-2000 GMC Envoy
1996-2000 Oldsmobile Bravada
with 4.3L V6 Engine (VINs W, X -- RPOs L35, LF6)
This bulletin is being revised to include additional model years. Please discard Corporate Bulletin Number 99-06-02-012C (Section 06 -- Engine).
Condition
Some customers may comment that the heater is inoperative, blows cold air, engine may exhibit an overheat condition or the coolant reservoir has rust in it.
Cause
Vehicles equipped with DEX-COOL® coolant, which may have been operated for extended periods of time with a low coolant level, usually in excess of 32,000 km (20,000 mi), may be susceptible to the formation of a rust-like material in the cooling system.
Correction
Flush the cooling system using the repair procedures that follow.
Parts and equipment required/suggested for this correction are listed below.
1 each *Prestone® Flush and Fill Kit #AF-KITP U.S. (#00050 in Canada). This kit can be obtained from your local parts supplier and can be used on all vehicles repaired under this procedure. Save it after performing the repair, as it is reusable.
1 each *Prestone® Heavy Duty Cooling System Cleaner, GM P/N 12346500 - 1 per vehicle. This cleaner is in powder form and contains a neutralizer. Do not substitute other cleaners. The diluted cleaners that are available in liquid form are not recommended for this repair.
5.7 L (6 qt) of 100% (non-diluted) DEX-COOL® coolant (GM Spec 6277M).
1 each new thermostat, GM P/N 12563335.
2 each new radiator cap, GM P/N 15075565.
1 each *Prestone® yellow funnel. This funnel can also be obtained from your local parts supplier. It fits snugly into the radiator opening for an easy fill and is reusable.
*We believe this source and their products to be reliable. There may be additional manufacturers of such products. General Motors does not endorse, indicate any preference for or assume any responsibility for the products from this firm or for any such items which may be available from other sources.
Important
Verify the fuel level in the fuel tank. The fuel level should be above ¼ tank before this procedure is started.
As a precaution, verify the oil level in the crankcase. Add the amount required to bring the oil level into the normal range.
It is recommended the vehicle be placed in a position so that the following are available:
A sanitary sewer -- not a storm drain, etc
A monoxivent system (if the outside temperature is less than 10°C (50°F)).
Hot running water
Notice
Due to the complexity of these procedures, the following repair steps must be strictly adhered to in order to achieve the intended results. Any deviation or substitution may result in sub-standard cleaning/flushing results or system damage.
Diagnostic Procedure
Install the Scan Tool. This will allow monitoring of the coolant temperature throughout the procedure.
Caution
As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the radiator cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap. Under some conditions, the engine coolant is combustible.
Important
The installation of a NEW radiator cap at the beginning of this procedure and the second new cap at the end of the repair procedure is necessary in order for the correct pressure to be achieved and for the repair to be completed successfully.
The radiator cap is NOT a good indicator of the general condition of the cooling system. Typically the underside of the radiator cap will exhibit a greater amount of contamination than the rest of the system. It is important to evaluate the condition of the cooling system by checking the following before beginning the repair procedure:
Remove the radiator cap. Install a new radiator cap, GM P/N 15075565. A properly operating radiator cap is essential for this procedure to work properly. Be sure to wipe off all radiator cap sealing surfaces prior to installation.
Start the engine.
Using a flashlight or lead light, look into the radiator. From the right side of the vehicle, peer into the radiator toward the left side of the vehicle. Observe the top three rows (or tubes) of the radiator. (It may be necessary to drain off some of the coolant to see the top three rows of the radiator). If it appears the coolant is able to flow through the third row down from the top, the vehicle should be repaired using Procedure A. If it appears the coolant is NOT able to flow through the third row down from the top, then the vehicle should be repaired using Procedure B.
Stop the engine.
Repair Procedure A & B
Important
If available, use coolant exchanger Pro-Fill 42-75100-KM, Power Flush 211-07601/DEX (available through the GM Dealer Equipment program), or equivalent to evacuate the system of coolant. Follow the manufacturer's instructions for exchanging used coolant with new coolant. However, for this procedure, use water in place of new coolant. Be sure to exchange 1½ times the cooling system capacity of the vehicle with water. This will ensure that only water remains within the cooling system. Once the coolant has been displaced with water, drain the water from the radiator.
If you are located within an area which regulates the disposal of used coolant (check with your local water treatment facility), all coolant and coolant/water mixture must be captured until the water runs clear of coolant. Use a clean 208 L (55 gal) drum or similar to contain the waste coolant. Refer to Corporate Bulletin Number 00-06-02-006 for information on coolant recycling and removal services.
Drain and properly dispose of the coolant.
Caution
Any obstructions in the hoses to or from the coolant recovery bottle may cause over-pressurization of the cooling system. This over-pressurization could result in serious personal injury.
Inspect the following hoses in order to assure there are no obstructions and the coolant is able to flow freely:
The hose to the coolant recovery bottle.
The relief hose from the coolant recovery bottle.
Disconnect both coolant hoses to the heater core from the engine.
Back flush the heater core for 5 minutes after clear water is present. Pressurized water not to exceed 345 Kpa (50 psi), may be used.
Reinstall the heater return hose to the engine.
Install the radiator cap and properly tighten.
Install the "T" from the flush and fill kit to a 25.4 cm (10 in) piece of 19 mm (¾ in) heater hose. Tighten the clamp.
Install the hose to the engine. Tighten the clamp.
Install the other end of the "T" in the heater core inlet hose. Tighten the clamp.
Disconnect the upper radiator hose from the radiator. Properly position the hose, so the accessory drive belt or any pulley/belt cannot touch the hose.
If you used coolant exchange equipment, disconnect it.
Attach a garden hose to the "T" of the flush and fill kit. Turn on the water and back flush the cooling system for at least two minutes after the water runs clear.
Start the engine and continue back flushing the cooling system for five additional minutes.
Turn the engine "OFF".
Turn the water "OFF".
Re-attach the upper radiator hose to the radiator.
Open the radiator drain and drain all water from the radiator.
Remove the lower left water pump crossover bolt. This allows lowering the water level in the left side of the engine.
After the water stops running from the water pump bolt hole, reinstall the bolt.
Close the radiator drain.
Mix the Prestone® Heavy Duty Cooling System Cleaner, GM P/N 12346500, in approximately 3 L (3 qt) of warm water. Pour the mixture into the radiator. Top off the system with plain water and reinstall the radiator cap.
Run the engine at 1600 to 1800 RPM with the air conditioning in the maximum cool position. To achieve the 1600 to 1800 RPM, place a dime between the closed throttle stop and the screw. This screw should never be adjusted, under any circumstance. Its only purpose is to keep the throttle plate from sticking in the bore when the throttle is slammed shut. It is not a minimum idle (RPM) control adjustment screw.
Registered User
Joined: Apr 2009
Posts: 43
**Continuation ONE**
Important
It is imperative that all air pockets have been removed from the cooling system in order for the cleaning procedure to be effective.
Service Procedure A
For Service Procedure A, the cleaner should be left in the system for three hours (after normal operating temperature of the cooling system has been achieved). Normal operating temperature is when the coolant temperature stabilizes around 98°C (200°F). The best results are obtained when the coolant temperature is between 98°C (200°F) and 110°C (230°F). DO NOT EXCEED 113°C (235°F). Use the Scan Tool to determine when this point has been reached. When this temperature has been reached, start the clock. Periodically (every twenty minutes or so), monitor the coolant temperature and engine during the three hour run time. A half hour has been built into the actual labor time to cover for the time spent monitoring the engine, etc.
In order to achieve a constant temperature of 98°C (200°F) to 110°C (230°F) during this procedure, maintain the idle speed, turn on the A/C or partially close the hood.
Service Procedure B
For Service Procedure B, the cleaner should be left in the system for two and a half hours (after normal operating temperature of the cooling system has been achieved). Normal operating temperature is when the coolant temperature stabilizes around 98°C (200°F). The best results are obtained when the coolant temperature is between 98°C (200°F) and 110°C (230°F). DO NOT EXCEED 113°C (235°F). Use the Scan Tool to determine when this point has been reached. When this temperature has been reached, start the clock. Periodically (every twenty minutes or so), monitor the coolant temperature and engine during the two and a half hour run time. A half hour has been built into the actual labor time to cover for the time spent monitoring the engine, etc.
In order to achieve a constant temperature of 98°C (200°F) to 110°C (230°F) during this procedure, maintain the idle speed, turn on the A/C or partially close the hood.
Important
The vehicle should not be left idling outdoors when the ambient temperature is below 10°C (50°F). The flushing procedure relies on heat as a catalyst in order to be effective. Ambient temperatures below 10°C (50°F) do not allow sufficient cycling of the thermostat to effectively clean the cooling system.
Turn off the engine.
Remove the dime from the closed throttle stop screw. Do NOT remove the radiator cap. Following the procedure listed below will assist you in draining the cooling system thoroughly.
Place a drain pan under the radiator drain hose.
Caution
The cooling system and coolant are hot and under pressure. Loosen only the radiator drain until the pressure has been released from the cooling system and follow the procedures exactly in this bulletin, using normal safety precautions to avoid being injured by the hot coolant mixture.
Loosen the radiator drain. Drain approximately 1 L (1 qt) of liquid from the system.
After the pressure has been released from the cooling system, slowly loosen the radiator cap to the safety stop. Do not remove the cap (This releases the spring pressure on the secondary seal while retaining the primary seal to the top of the filler neck and will allow the coolant reservoir to be evacuated).
When the coolant reservoir is empty, re-tighten the radiator cap fully.
Remove the cap from the flush and fill "T". This will allow the coolant to be siphoned from the heater core and the engine block.
When the water has stopped coming out of the radiator drain hose, close the radiator drain. Do not place the cap on the "T".
Using Prestone® Heavy Duty Cooling System Cleaner, GM P/N 12346500, mix the neutralizer (from the bottom of the can) with approximately 3 L (3 qt) of warm (shower temperature) water.
Notice
Do not put cold water into a hot engine as engine damage may occur.
Under no circumstances should the neutralizer be left in the cooling system for any longer than ten minutes once the vehicle has reached operating temperature (thermostat open). The neutralizer is corrosive to aluminum and will damage system components if it is left in the cooling system for longer than ten minutes.
Pour the mixture from the step above into the radiator.
Completely refill the cooling system with warm to hot water through the "T". When the radiator is full, install the radiator cap to the safety catch. Continue to fill until the overflow reservoir is filled to the hot line on the reservoir.
Remove the fill hose and install the cap on the "T" and the radiator fully.
Important
It is imperative that all air pockets have been removed in order for the procedure to be effective.
Start the engine. After engine speed stabilizes, reinstall the dime between the closed throttle stop and the screw. With the A/C on, bring the cooling system back to normal operating temperature and follow the directions on the can.
Turn off the engine.
Remove the dime from the closed throttle stop and the screw.
Caution
As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the radiator cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap.
Drain the cooling system, following the procedure listed in Step 24 above.
Do not close the radiator drain. Leave it open.
Disconnect the upper radiator hose from the radiator. Properly position the hose, so the accessory drive belt or any pulley/belt cannot touch the hose.
Attach a garden hose to the "T" of the flush and fill kit. Turn on the water and back flush the cooling system for at least two minutes after the water runs clear.
Start the engine and continue back flushing the cooling system for five additional minutes.
Turn the engine "OFF".
Turn the water "OFF".
Close the radiator drain.
Important
If the repair is a Procedure A, go to Step 40.
If the repair is a Procedure B, remove the radiator and have it recorded and steam clean the end tanks. After reinstalling the radiator, continue to Step 40.
Remove the air cleaner housing and tube assembly from the throttle body.
Remove the two nuts holding the throttle cable bracket to the throttle body and position the bracket and the cables out of the way.
Remove the thermostat.
Remove the previously installed flush kit "T" and hose. Save for future use on other vehicles.
Install the heater inlet hose to the intake manifold and secure with the original spring clamp.
Inspect the thermostat opening and cover for foreign material. Clean if necessary.
Remove the left lower water pump crossover bolt to drain the left side of the block and the left cylinder head.
Install sealant to the bolt threads, using GM P/N 12346004 (Canada GM P/N 10953480), or equivalent and reinstall the water pump crossover bolt. Tighten
Tighten the bolt to 41 N·m (30 lb ft).
If available, use coolant exchanger Pro-Fill, Power Flush, or equivalent to fill the system with 50/50 DEX-COOL® coolant. If a coolant exchanger is not available, proceed to the next step now. Follow the manufacturer's instructions for system fill/coolant exchange. If you are using coolant exchange equipment, you will need to install a new thermostat, GM P/N 12563335 and top off the system with clean drinkable water prior to exchanging. After exchanging, install the upper radiator hose and clean out the coolant recovery bottle. Proceed to Step 56.
Pour 5.6784 L (6 qts) of 100% (not pre-mixed) DEX-COOL® coolant into a clean container.
Using a clean funnel, pour as much of the 100% DEX-COOL® coolant that you can into the engine through the thermostat opening.
Install a new thermostat, GM P/N 12563335. Tighten
Tighten the bolt to the specified torque of 19 N·m (14 lb ft).
Hold the upper radiator hose in the straight up position and pour 0.473 L (1 pint) of the 100% DEX-COOL® coolant into the hose.
Install the upper radiator hose to the radiator and properly position the clamp.
Flush the coolant recovery bottle thoroughly.
Complete the fill of the cooling system with the balance of the 5.7 L (6 qt) of 100% DEX-COOL® coolant and top off with plain water. If the water is not drinkable, do not use. Water must be clean and fresh.
Important
The second new radiator cap must be installed at this point of the procedure. It is possible that small contaminants may have become lodged in portions of the first cap during the cleaning procedure.
Clean the radiator cap sealing surfaces on the radiator. Install the radiator cap, GM P/N 15075565.
Important
It is imperative that all air pockets have been removed in order for the cooling system to function properly.
Run the engine to operating temperature with the air conditioning in the maximum cool position for ten minutes.
Caution
As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the radiator cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap. Under some conditions, the engine coolant is combustible.
It is imperative that all air pockets have been removed from the cooling system in order for the cleaning procedure to be effective.
Service Procedure A
For Service Procedure A, the cleaner should be left in the system for three hours (after normal operating temperature of the cooling system has been achieved). Normal operating temperature is when the coolant temperature stabilizes around 98°C (200°F). The best results are obtained when the coolant temperature is between 98°C (200°F) and 110°C (230°F). DO NOT EXCEED 113°C (235°F). Use the Scan Tool to determine when this point has been reached. When this temperature has been reached, start the clock. Periodically (every twenty minutes or so), monitor the coolant temperature and engine during the three hour run time. A half hour has been built into the actual labor time to cover for the time spent monitoring the engine, etc.
In order to achieve a constant temperature of 98°C (200°F) to 110°C (230°F) during this procedure, maintain the idle speed, turn on the A/C or partially close the hood.
Service Procedure B
For Service Procedure B, the cleaner should be left in the system for two and a half hours (after normal operating temperature of the cooling system has been achieved). Normal operating temperature is when the coolant temperature stabilizes around 98°C (200°F). The best results are obtained when the coolant temperature is between 98°C (200°F) and 110°C (230°F). DO NOT EXCEED 113°C (235°F). Use the Scan Tool to determine when this point has been reached. When this temperature has been reached, start the clock. Periodically (every twenty minutes or so), monitor the coolant temperature and engine during the two and a half hour run time. A half hour has been built into the actual labor time to cover for the time spent monitoring the engine, etc.
In order to achieve a constant temperature of 98°C (200°F) to 110°C (230°F) during this procedure, maintain the idle speed, turn on the A/C or partially close the hood.
Important
The vehicle should not be left idling outdoors when the ambient temperature is below 10°C (50°F). The flushing procedure relies on heat as a catalyst in order to be effective. Ambient temperatures below 10°C (50°F) do not allow sufficient cycling of the thermostat to effectively clean the cooling system.
Turn off the engine.
Remove the dime from the closed throttle stop screw. Do NOT remove the radiator cap. Following the procedure listed below will assist you in draining the cooling system thoroughly.
Place a drain pan under the radiator drain hose.
Caution
The cooling system and coolant are hot and under pressure. Loosen only the radiator drain until the pressure has been released from the cooling system and follow the procedures exactly in this bulletin, using normal safety precautions to avoid being injured by the hot coolant mixture.
Loosen the radiator drain. Drain approximately 1 L (1 qt) of liquid from the system.
After the pressure has been released from the cooling system, slowly loosen the radiator cap to the safety stop. Do not remove the cap (This releases the spring pressure on the secondary seal while retaining the primary seal to the top of the filler neck and will allow the coolant reservoir to be evacuated).
When the coolant reservoir is empty, re-tighten the radiator cap fully.
Remove the cap from the flush and fill "T". This will allow the coolant to be siphoned from the heater core and the engine block.
When the water has stopped coming out of the radiator drain hose, close the radiator drain. Do not place the cap on the "T".
Using Prestone® Heavy Duty Cooling System Cleaner, GM P/N 12346500, mix the neutralizer (from the bottom of the can) with approximately 3 L (3 qt) of warm (shower temperature) water.
Notice
Do not put cold water into a hot engine as engine damage may occur.
Under no circumstances should the neutralizer be left in the cooling system for any longer than ten minutes once the vehicle has reached operating temperature (thermostat open). The neutralizer is corrosive to aluminum and will damage system components if it is left in the cooling system for longer than ten minutes.
Pour the mixture from the step above into the radiator.
Completely refill the cooling system with warm to hot water through the "T". When the radiator is full, install the radiator cap to the safety catch. Continue to fill until the overflow reservoir is filled to the hot line on the reservoir.
Remove the fill hose and install the cap on the "T" and the radiator fully.
Important
It is imperative that all air pockets have been removed in order for the procedure to be effective.
Start the engine. After engine speed stabilizes, reinstall the dime between the closed throttle stop and the screw. With the A/C on, bring the cooling system back to normal operating temperature and follow the directions on the can.
Turn off the engine.
Remove the dime from the closed throttle stop and the screw.
Caution
As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the radiator cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap.
Drain the cooling system, following the procedure listed in Step 24 above.
Do not close the radiator drain. Leave it open.
Disconnect the upper radiator hose from the radiator. Properly position the hose, so the accessory drive belt or any pulley/belt cannot touch the hose.
Attach a garden hose to the "T" of the flush and fill kit. Turn on the water and back flush the cooling system for at least two minutes after the water runs clear.
Start the engine and continue back flushing the cooling system for five additional minutes.
Turn the engine "OFF".
Turn the water "OFF".
Close the radiator drain.
Important
If the repair is a Procedure A, go to Step 40.
If the repair is a Procedure B, remove the radiator and have it recorded and steam clean the end tanks. After reinstalling the radiator, continue to Step 40.
Remove the air cleaner housing and tube assembly from the throttle body.
Remove the two nuts holding the throttle cable bracket to the throttle body and position the bracket and the cables out of the way.
Remove the thermostat.
Remove the previously installed flush kit "T" and hose. Save for future use on other vehicles.
Install the heater inlet hose to the intake manifold and secure with the original spring clamp.
Inspect the thermostat opening and cover for foreign material. Clean if necessary.
Remove the left lower water pump crossover bolt to drain the left side of the block and the left cylinder head.
Install sealant to the bolt threads, using GM P/N 12346004 (Canada GM P/N 10953480), or equivalent and reinstall the water pump crossover bolt. Tighten
Tighten the bolt to 41 N·m (30 lb ft).
If available, use coolant exchanger Pro-Fill, Power Flush, or equivalent to fill the system with 50/50 DEX-COOL® coolant. If a coolant exchanger is not available, proceed to the next step now. Follow the manufacturer's instructions for system fill/coolant exchange. If you are using coolant exchange equipment, you will need to install a new thermostat, GM P/N 12563335 and top off the system with clean drinkable water prior to exchanging. After exchanging, install the upper radiator hose and clean out the coolant recovery bottle. Proceed to Step 56.
Pour 5.6784 L (6 qts) of 100% (not pre-mixed) DEX-COOL® coolant into a clean container.
Using a clean funnel, pour as much of the 100% DEX-COOL® coolant that you can into the engine through the thermostat opening.
Install a new thermostat, GM P/N 12563335. Tighten
Tighten the bolt to the specified torque of 19 N·m (14 lb ft).
Hold the upper radiator hose in the straight up position and pour 0.473 L (1 pint) of the 100% DEX-COOL® coolant into the hose.
Install the upper radiator hose to the radiator and properly position the clamp.
Flush the coolant recovery bottle thoroughly.
Complete the fill of the cooling system with the balance of the 5.7 L (6 qt) of 100% DEX-COOL® coolant and top off with plain water. If the water is not drinkable, do not use. Water must be clean and fresh.
Important
The second new radiator cap must be installed at this point of the procedure. It is possible that small contaminants may have become lodged in portions of the first cap during the cleaning procedure.
Clean the radiator cap sealing surfaces on the radiator. Install the radiator cap, GM P/N 15075565.
Important
It is imperative that all air pockets have been removed in order for the cooling system to function properly.
Run the engine to operating temperature with the air conditioning in the maximum cool position for ten minutes.
Caution
As long as there is pressure in the cooling system, the temperature can be considerably higher than the boiling temperature of the solution in the radiator without causing the solution to boil. Removal of the radiator cap while the engine is hot and pressure is high will cause the solution to boil instantaneously - possibly with explosive force - spewing the solution over the engine, fenders and the person removing the cap. Under some conditions, the engine coolant is combustible.
Registered User
Joined: Apr 2009
Posts: 43
**Continuation TWO - Final**
Turn the engine "OFF" and let it cool.
Check the coolant concentration for a 50/50 mix, using refractometer J 26568 (Centigrade scale) or J 23688 (Fahrenheit scale). Follow the manufacturer's directions for using the coolant tester. Unless your coolant tester has a provision for temperature correction, it is imperative that the correct coolant temperature is achieved when testing the coolant. If the coolant is warmer or cooler, the reading may be incorrect.
Top off the radiator and fill the coolant recovery bottle to 2.54 cm (1 in) above the full hot mark on the coolant reservoir. Add the appropriate coolant mixture to come to a 50/50 mix of the DEX-COOL® coolant.
Important
To assure intended system performance, inform the customer that the cooling system MUST be maintained in a completely full condition.
Check the coolant concentration for a 50/50 mix, using refractometer J 26568 (Centigrade scale) or J 23688 (Fahrenheit scale). Follow the manufacturer's directions for using the coolant tester. Unless your coolant tester has a provision for temperature correction, it is imperative that the correct coolant temperature is achieved when testing the coolant. If the coolant is warmer or cooler, the reading may be incorrect.
Top off the radiator and fill the coolant recovery bottle to 2.54 cm (1 in) above the full hot mark on the coolant reservoir. Add the appropriate coolant mixture to come to a 50/50 mix of the DEX-COOL® coolant.
Important
To assure intended system performance, inform the customer that the cooling system MUST be maintained in a completely full condition.
I bleed Oldsmobile
Joined: Dec 2007
Posts: 1,390
From: Iowa
Last time I took my 99 Intrigue to the shop for a waterpump my mechinac told me to get rid of that stuff and go with the regular anitfreeze.........So I did with no problems a year and a half later..............Jerr
Registered User
Joined: Jan 2008
Posts: 87
From: Ontario
I had the sludge buildup in my 2000 Grand Prix 3.8....So much so it was interferring with the coolant level sensor...a bit of sludge would sit on the sensor and cause it to come on indicating low levels. I thought at first it was the sensor...after some trouble shooting and keeping my original sensor I flushed and switched over to the green stuff thats worked for many many years before long life Dexcool came around, and my sensor issues went away and 2 years later I'm likely almost due to change it again but have had no problems using the green prestone
Registered User
Joined: Apr 2009
Posts: 43
Local radiator shop (old style, you know, the kind that will re-core, not just push a "new" radiator on you)
He was all too familiar with the Dexcool sludge... long story short. Performed chemical flush, removed and cleaned components, replaced coolant with traditional green, he even did an engine degrease/clean... $120! (All is working as designed again)
Very happy!
He was all too familiar with the Dexcool sludge... long story short. Performed chemical flush, removed and cleaned components, replaced coolant with traditional green, he even did an engine degrease/clean... $120! (All is working as designed again)
Very happy!
Registered User
Joined: Mar 2008
Posts: 422
From: North Ridgeville, Ohio
I think I may have been one of the few people that have not had problems with Dexcool. I had a 2000 Grand Prix with a 3.8 N/A that I got with 68,000 miles. Shortly after I bought it I had the coolant changed by the type of machine they use at quick lube places. It is not as good as a flush, but it was still fine. I had intake gasket failures, but they were not coolant related. I replaced the upper plastic plenum with the updated one and never had a problem after that for more than 100,000 miles. The coolant never sludged up and it looked great. I think I may have changed the coolant one other time the same way it was changed the first time. I never had any radiator leaks, water pump problems, bad heater cores, or hose failures. It was totaled at around 190,000 miles and it was still running great with no engine cooling problems.
On my Grandpa's Buick with the same engine, he did have a coolant related intake gasket failure at around 100,000 miles. It ended up hydro locking the engine. I changed the intake manifold with the same one I used on my car and it is still running great over a year later with no coolant loss or sludging.
Here is the manifold I used on both cars, it comes with gaskets also.
http://cgi.ebay.com/ebaymotors/GM-3-8L-3800-OLDS-BUICK-UPPER-INTAKE-MANIFOLD-PLENUM_W0QQitemZ220439741604QQcmdZViewItemQQptZMot ors_Car_Truck_Parts_Accessories?hash=item33533b84a 4&_trksid=p4506.c0.m245&_trkparms=65%3A12|39%3A1|7 2%3A1205|240%3A1318
On my Grandpa's Buick with the same engine, he did have a coolant related intake gasket failure at around 100,000 miles. It ended up hydro locking the engine. I changed the intake manifold with the same one I used on my car and it is still running great over a year later with no coolant loss or sludging.
Here is the manifold I used on both cars, it comes with gaskets also.
http://cgi.ebay.com/ebaymotors/GM-3-8L-3800-OLDS-BUICK-UPPER-INTAKE-MANIFOLD-PLENUM_W0QQitemZ220439741604QQcmdZViewItemQQptZMot ors_Car_Truck_Parts_Accessories?hash=item33533b84a 4&_trksid=p4506.c0.m245&_trkparms=65%3A12|39%3A1|7 2%3A1205|240%3A1318
Registered User
Joined: Mar 2008
Posts: 422
From: North Ridgeville, Ohio
They did come out with an aluminum upper plenum for the newer style 3800 engines, I believe that was in 04, not sure though. You can swap those onto your engine pretty easily. I think the biggest part is that you need an adapter for the throttle body because the new style uses drive by wire.
Here is the adapter, https://www.zzperformance.com/grand_...=255&catid=113
Here is the aluminum manifold, https://www.zzperformance.com/grand_...=989&catid=113
Here is a link on the swap, http://www.automotivehelper.com/topic701174.htm
