I have a 1987 Salon with a stock 307. When the 307 reaches normal operating temp it runs rough (valve clatter, no power, and hard shifts). When its cold it runs fine.
Local machanics cant solve issue.
Any suggestions?

 

Check this out. It might help.

http://performanceolds307.tripod.com/id4.html

 

I had a similar problem but it was related to the solenoid for the lockup torque converter on the transmission. Since the converter stays locked there isnt any slippage thats needed before reaching cruising speed. Its almost like trying to accelerate a stick car from start in high gear. Its an easy fix but ya have to do it from under the trans pan. You might try disconnecting the wires/plug for the solenoid on the side of the trans and see if it makes a difference.

 

Thats an awesome site. Thanks for the tip. I'll try that first.

 

Well, I changed out the Ignition Control Module, didnt solve the issue.
I sent an email to Mondello Olds Performance, got a reply back to use 20/50 oil and call their tech line next week. I called a mechanic that I used to deal with back home and he stated that the 307 had some weak metal that was used on the heads, something like an alloy tray that the was beneath the valves. He said the metal has worn down and the valves are opening and closing as they should because of that. There's a rebuild kit for that. Guess I'll go that route or replace the 307 with the 350 out of my 73 cutlass.

 

You can believe that BS from Mondello and your mechanic (forgive me for being frank) but I dont....especially since you say the car runs fine cold and shifts hard when hot.....I dont see the link between valve trouble and the transmission shifting...I still say the trouble is most likely what I suggested above....easy to check and a 50 dollar part.

 

I'm up for anything cheap!
Let me re-state what the symptoms are.

Cold= Car runs fine

Hot= Very sluggish on acceleration from dead start, knocking, valve clatter, hard shifts. On decceleration, I'd say 2nd to 1st gear, alot of lunging and jerking.

So you say that it may be the solenoid for the lockup torque converter and suggest that I disconnect the plug on the side of the tranny and.......?
Drive it until its hot and see if that stops the issue? If it does, change the selenoid?

 

The symptoms you describe are exactly what my 85 Delta was doing and my 84 Custom Cruiser...all with the 307 and overdrive trans....Yes pull the 2 wire connector while cold I think its only 2 wires from the driver's side of the trans and see what happens....After I swapped the solenoid it was as if I had a new car!

 

okay, Ive pulled the plug and I'm gonna drive 'til its hot and see if it still acts the same. If not, I'll change the solenoid.

 

You are The Man!

I unplugged it and drove for 40 miles and the issue went away!

I guess that I should change it so that its like it should be and maybe I'll get better fuel economy.

Thanks for your help on that one.
Now maybe you can tell me why the heater isnt putting out hot air. The car ran hot last week and when I got home the small hose that runs from the water pump up to the thermostat housing was blown. I replaced it as well as the thermostat and it doesnt run hot anymore but the heater has stopped putting out hot air. It isnt dumping coolant in the floorboard. What do ya think?

 

Glad I could help......Guess 35 years of turning wrenches has gained me a little knowledge. As for heat, ya may have to check the heater control valve back at the far rt side of intake. Some are vacuum operated and some are electric. It must open to allow hot water to flow thru heater core. Of course your fan motor needs to operate as well. Check too to see if the temp slider on the dash control is moving a damper door. It regulates temp. Lastly make sure you are not low on coolant as it will not allow enough coolant to flow thre heater core......

 

Thanks again.

 

Good thread! I am not a great fan of Mondello either. They don't seem to want to really help someone unless there is a big order for them in the future, and then only until the check clears....

 

Ive built an engine with all of Mondello's parts.....but that was years ago when he was pretty much the only game in town when it came to Olds Performance. Back then he was helpful and you could speak to him directly by phone....now all I hear is bad about him but personally havent dealt with him in about 20 years. It also burns me when so called mechanics start spewing crap like weak metal that wipes out valves etc to someone who wants an answer and doesnt know enough to know the difference between truth and pure BS. Hopefully those seeking real info can find it on sites like these.

 

Amen!

 

yes so true. I always think twice about the advice I give and try to always give a caveat or say it is my opinion about something if I am not sure or it is not real facts. I have been wrong and embarassed myself before. Crow don't taste too good......

 

I pulled off the vacuum line going to the heater control, its plastic, not rubber like most, there isnt any vacuum from the control valve outlet, nor the vacuum line. I checked both hoses coming off of the firewall and theyre both hot. If the control valve wasnt working would both hoses be hot?

 

Look behind the glove box that is where the blend air door is try to move it manualy there is a plastic part that breaks often

 

"Check too to see if the temp slider on the dash control is moving a damper door. It regulates temp"......If the inlet an outlet hoses are hot from heater core most likely it is your flapper under the dash

 

Okay Guys, I checked the door behind the glovebox. Everything is opening and closing as it should.
I'm baffled once again.
Okay, the heater hose coming off of the control valve is the inlet? It gets real hot.
The heater hose coming off of the firewall going back to the water pump is the outlet? It doesnt get near as hot.
The vacuum line going to the control valve runs back under the firewall, should it have vacuum? Where does it get the vacuum?
Should there be vacuum coming off of the control valve?

Could the core be clogged?

 

I believe vacuum opens the heater valve. It should get vacuum when the button is selected for heat. Vacuum goes to the dash control from a manifold vacuum source on the engine. Look and make sure vacuum is indeed coming from the intake to the controller on the dash. You could put vacuum from the manifold right to the valve and see if ya get heat.

 

I went ahead and got a new control valve, pulled off the old one and broke the new one putting it on. Man those things arent made to go on easy, its almost impossible to get a wrench on them. The parts store only had the one, so I used my resourcefulness and went to my service truck and pulled out some black iron. I used a close nipple and another fitting or two and hooked up the hose to it. Guess what? The heater now works!!! Ha Ha!
I'll get the parts store to order a new one. Any suggestions on the best way to put them in?

 

Ok then the problem is with the valve or lack of vacuum to it......Yes they are hard to get at.....It is important to get the correct valve so it fits right. Usually I break or saw off the tube then get a box wrench and turn the fitting out of the manifold since there is very little room to work. The new one needs some teflon tape on the threads and spin it in by hand then try a open end wrench to snug it....dont try and make it super tight. They say you shouldnt just use a piece of pipe as there will be too much pressure for the heater core and could rupture it although I never had a problem. But if ya look at a car without a control valve the fitting in the manifold has a very small hole in the center to restrict flow.