Super88chris

Hey guys I知 new here, so I知 having this issue with my 55 olds super 88. Ever time the car warms up it poors coolant out of the over flow hose a lot and steams. I have a new thermostat and radiator and my water pump seems to be fine, just put a new gasket on because it was leaking but now it痴 not. I know the car sat for at least 10 to 15 years before I got it, it runs decent except this issue.

oldcutlass

It could be due to you overfilling the radiator or you have a bad cap. If it's not either of those, you may have a blown head gasket.

Super88chris

ok good to know! For awhile when I ran the car it would turn the coolant or water all brown and rusty looking, could there be too much rust in the block causing this? Also how does a cracked head casket cause this issue? I知 still learning about these old cars so forgive me.

Vintage Chief

I'm w/ Eric. Often times a car w/ a bad radiator cap will boil over when NOT being driven. The radiator cap cannot maintain the pressure & allows the boiling coolant to overflow. Many times the car will not boil over while being driven since the air flow across the radiator assists in driving down the coolant temperature. Soon after engine shut-down, the radiator coolant begins to overflow. Radiator caps are inexpensive. Ensure you have the correct radiator cap with the correct PSI rating.

There's always too much rust in the block on a 68 year old car. But, in & of itself, at this point, you should be addressing an overflow condition & not necessarily worrying about the rust. The rust (if there is any) isn't going to inherently cause your overflow condition.

Check your radiator to ensure it's flowing adequately. With the radiator cap OFF, start engine. You should see very good circulation of water through the cores on a new radiator. As Eric pointed out, ensure you aren't overfilling the radiator. You should generally be ~1" below the top of the radiator top plate/seal. Most times there's a fill mark line - use a flashlight to visualize. Next, put on the new radiator cap. It should hold pressure and not boil over.

EDIT: I should note a well contaminated block with tons of rust could very well cause premature failure of a radiator cap.

Vintage Chief

If a head gasket is leaking:

(1) Hot exhaust gases can leak into the cooling system; or,
(2) Coolant can leak into the cylinders to be burned off as steam.

In both cases the end result is an overheating engine.
You can often/sometimes see white smoke (steam) exiting the exhaust pipe &/or the exhaust smells sweet - like coolant.

Olds64

Definitely get a new radiator cap. It'd probably be a good idea to flush your coolant system too. There are a few recent threads on using Thermocure to flush a cooling system.

https://www.summitracing.com/parts/sum-tc001

Make sure you use distilled water when you refill your cooling system. I recently went through 20 gallons flushing and refilling the coolant in my classic diesel truck.

Super88chris

So I have a 55 olds super 88, I have mentioned that while it痴 running the temps tire climbs very slowly and does not go down and when I shut it off the coolant spits out of the radiator over flow hose with steam. There is no coolant in the oil I致e checked it while and running and while cold. My water pump is fine as far as I can tell and thermostat is new, but I just noticed when I shut it off the bottom radiator hose is cooler than the top hose. Any advice please?

oldcutlass

I merged your 2 threads, there is no reason to start multiple threads for the same issue.

Vintage Chief

I'm not sure why you posted again. For a minute I thought you had created a new thread. Anyways...the bottom hose should always be cooler than the top hose since the radiator INLET hose resides on the top and contains hot coolant FROM the engine & the bottom hose has coolant which has passed through the radiator heading back towards the block (coolant passageways) of the engine. Maybe I'm missing something, but what you're describing is normal.

Vintage Chief

I thought I was losing my mind since I thought the OP created a new thread of the exact same issue.

Super88chris

Yeah sorry I知 still learning how to use this site. Anyways ok good to know. Let痴 say there is rust in my block, how could I clean it without pulling the engine out?

Vintage Chief

Easier to remove the chassis by lifting the chassis off the frame and leave the engine as it is on its motor mounts....JUST KIDDING!!!!!

There has been significant discussions regarding this product:

Thermocure

Super88chris

Hmm ok I値l look into it. Last time I put a stop leak fluidbin my radiator it clogged it up in result having to get rid of it and for all I know could be causing the issue I知 having now.

Vintage Chief

Thermocure is NOT a stop leak product.

Thermocure product is made of Diammonium Phosphate (and minor constituents of sodium salts) - the general term is DAP. NOT to be confused with the DAP manufacturer who sells caulking compounds. It removes rust - again, it is NOT a stop leak product.

Super88chris

Ok do they have it at autozone or car parts stores? Any chance of pulling the drain plugs and poking around in their and rinsing with water to clean the rust?

Vintage Chief

Follow the link I already provided, click on "Where To Buy"

Tedd Thompson

If you are concerned about a head gasket issue you can rent a tester for no cost and purchase a testing liquid at any major parts house. This will tell you if exhaust gases are getting into the system through the head. Not very expensive but do the cheap stuff first, a flush and a new radiator cap never hurts. Tedd

Super88chris

I知 definitely concerned and thank you for the advice but I can稚 drive the car but I am going to try a flush

Super88chris

I posted in this thread awhile ago about how when my car heats up the temp gauge rises and steam blows out the overflow hose on the radiator. Well today I just replaced my head gaskets and the old ones didn稚 look broken, maybe worn but I replaced them anyways and put in a new water pump and the damn thing is still blowing out steam. However when I had the heads off I used a flat head and felt down in the the water jacket and it was filled with hard black stuff so I chipped away at t then flushed it out with water till it was clear. Anyways my car used to take a long to get up to temp and now it痴 heating up much quicker like 15 min or so and the temp gauge is in the middle. I pushed down on my thermostat to see if it went up and down and it did so I知 assuming it works? My radiator cap looks good too. Any ideas? I知 stumped

oldcutlass

Are you refilling the radiator each time to the top? After it pukes and cools what is the water level in the radiator? If it's a few inches below the neck, try restarting, let it heat up and see if it still pukes. The spring test on the thermostat that you performed tells you nothing on whether it is good or not.

Super88chris

I put some antifreeze in and it filled up then I ran it and when checked the level I couldn稚 see any in radiator so I知 guessing it needs more. I had some other stuff to do so that痴 as far as I got tonight but I値l try tomorrow and get a new thermostat. Anything else should try tomorrow?

oldcutlass

Did you change the radiator cap? Next time, measure how much you are adding. Don't fill all the way to the top, stop about 2" below.

Super88chris

no I didn稚 get a new radiator cap. I didn稚 fill it to the exact top just about 2 inches below.

Vintage Chief

Installation of a new radiator cap has been suggested on several occasions. The coolant system is designed to operate under a known pressure. The short of it is this - very simple to understand.

The radiator cap maintains the closed cooling system UNDER PRESSURE in order to raise the boiling point of liquid coolant. A cooling system NOT under the appropriate pressure will cause the liquid coolant to boil at a lower temperature. The boiling liquid coolant has one primary avenue to leave the cooling system - through the overflow. It's very difficult to determine the condition of a working vs. non-working radiator cap. Radiator caps are well known to fail - especially in a cooling system which has been in storage. Have a look at some radiator cap diagrams - there are many points of failure of a radiator cap.

FStanley

So here are the Steps I would do, and I went thru all of this stuff with my 69 Olds not so long ago.

1. Rent an Combustion Leak Tester tester for the coolant to rule out blown head gasket

https://www.oreillyauto.com/detail/c...ter/ren1/67094

2. Rent radiator and cap tester. Pressurize the system to 7lbs( I was corrected NOT 20lbs like I said ealier ... will damage something.., let sit overnight see if there is loss of cooling system pressure. Next test radiator cap to hold pressure. 7lbs for your car.. see if it holds.

https://www.oreillyauto.com/detail/c...kit/ren1/67085

if above fails, you have an issue and need to fix. fluorescent dye diagnostics could help you..

3. I'd buy a coolant recovery system

https://www.oreillyauto.com/shop/b/e...28universal%29

you will need to replace your radiator cap to a coolant recover one though.. so the coolant will return back into the radiator.

saw this, but not sure this will work..

https://www.oreillyauto.com/detail/c...obile-88?pos=0

Benefit is that your coolant in the radiator is always full and when hot the coolant does not end up on the ground. Works great on my 69.

also like others have alluded to, a good cleaned out and checked radiator, and flushed out engine block could also help. I got a ton of crude out of my 50 year old system, cooling improved a lot..

Good luck.

Fred

Super88chris

I put new head gaskets so it痴 not that. And my old ones weren稚 broken just worn I guess. But ok I値l try that and I値l get that blue devil radiator flush stuff cuz I知 sure that痴 still gunk in there after all I dug out

DFitz

Super88,

What ever you do, DO NOT PRESSURIZE THE SYSTEM TO 20 PSI!!!!!! In fact, nothing over 7 psi.

The Rancor heater valve will fail, and that will be a mess.

A blown head gasket, depending on where the problem is, shows up in one of 2 ways. First, white smoke in the engine exhaust. Radiator fluid gets into the combustion chamber and shows as white smoke out the tail pipe. Or, second, radiator fluid in the oil. You can tell this when you do an oil change. And, the engine will run pretty crappy, 6 or 7 cylinder sometimes. Unless you had any of these symptoms, I don't think you had a head gasket problem.

1. The '55 Olds has a 7 psi cap. Do not replace it with anything higher. As I said, the heater valve will fail.
2. Those extra 2" in the radiator header can help with cooling--I'll get to that. This is what happens. The hottest point in running the engine is about 15-20 min after you shut it off. The radiator heat soaks. If the cap is good, BTW DO REPLACE the cap, it will open the spring, and fluid will be released as the heat soaked pressure rises above 7 psi. Now that little bit of fluid is gone and can't cool the next time you run the car. Happens a little each time you run it. So you constantly have to put in more radiator fluid.
3. DO not us water, use radiator fluid. It has a higher boiling point than water, thus won't boil off. 50% mix glycol, and water.
4. Add a radiator recovery tank as already suggested. On the back side of the baffle right next to the radiator on the outlet side. You can see the tank in the top L of the picture.



This way you get to use those extra 2" in the radiator header, you don't lose any fluid, it overflows into the tank, as the radiator cools, it sucks the fluid back into the radiator. Using the radiator fluid/glycol will cool much better than water. And--you don't have to continually add fluid any more.

Everything above adds up to better cooling.

Keep us posted.

FStanley

also make sure your car is not running too hot. A infrared temp gun is your friend. should get about 20F drop from input to output of the radiator.. another thing that is happening with our old carbureted cars is that the ethanol blended gas make them run lean. Per Cliff Ruggles rebuild richening the carb a bit helps, it did for my 69..

Check vacuum advance for working, old rubber diaphrams give out, cause engine to run hot..

tnswt

Here's more regarding a recovery tank and cap.


https://classicoldsmobile.com/forums...ry-tank-84723/

Super88chris

should I only get ethanol free gas? Also my temp gauge doesn稚 have numbers, and my thermostat is for 180 so how do I know when it hits 180 and should start dropping a bit?? I致e looked it up and can not find how to read this gauge.

Vintage Chief

These beastly machines were produced during an era when digital instrument accuracy was not forthcoming.

You have this site bookmarked, right? It will explain how to read the temperature gauge (and other 'stuff'). NOTE: You can d/l that manual in .pdf format.

https://www.manualslib.com/manual/10...ldsmobile.html

Vintage Chief

Vintage Chief

Unless you're going to install more modern digital (exacting) instrument gauges, you will not know EXACTLY when the thermostat begins to open &/or is fully opened. Honestly, you won't know even w/ an exacting digital gauge since remember, the gauge is a meter (metric) which monitors temperature (not the mechanics of the thermostat itself). Yes, there's a relationship, but I'm not certain that relationship is noteworthy. If your temperature gauge isn't moving into the "H" (red zone), the thermostat should be considered to be performing the job it was designed to accomplish.

Super88chris

no I didn稚 have it but thank you that痴 awesome I値l check it out

DFitz

Super88,

Ethanol free gas would be better if you can get it. Out here in CA, hard to find.

What is a real problem is the ethanol will eventually ruin a part of your carburetor called the accelerator pump. The accelerator pump adds gas as you, would imagine, as you accelerate. The seal on the piston degrades with ethanol. It wasn't designed to be exposed to alcohol. If its running and accelerating ok, you should be fine.

As for the temp, at least on my car, 180 is exactly on the middle mark on your temp gage. My engine runs cool, but I have also heard that many of the more highly optioned cars run hotter.

Super88chris

well my accelerator pump kinda sucks and it痴 new but apparently the ones they sell in the kit are the wrong size. Mine has some hesitation to it. I知 just waiting to order the right one probably one of the leather ones. I think we have some ethanol free gas places here in this lib state I would think. I just saw in the manual as long as the temp gauge isn稚 in the red then it痴 within operating zone, which makes me nervous on an engine this old.

FStanley

and just as bad as the wrong size is the fact you need rebuild kit that is made for ethanol gasoline use. Otherwise it will just deteriorate over time unless you use 100% ethanol free gasoline all the time.

I gave up trying to rebuild my own carbs, good carb rebuilders can get nasty *** chemicals I can't get in CA, have ultrasonic cleaners, and some even bench flow or tune on a real engine.. ethanol really hosed my up good.. after the rebuild make sure you use an ethanol gas treatment like Stab-Bil makes like Marine 360 for stuff that sits a lot. and quality brand gasoline like Shell or Sunoco. No more problems afterwards.

talk to:

https://www.carburetor-parts.com/

and

https://carbkitsource.com/index.html

and
Don Monroe (253) 566-8488

Super88chris

oh wow that sucks! Yeah I値l call them. I値l most likely order a kit but I値l rebuild it since I know how now lol.

FStanley

This is a particular grip of mine in that what does C and H tell you??? I got the temp gun out one day and put a piece of cardboard in front of the radiator idling the car, and as the temp when up I wrote done the temp gun degrees and coorelated it to the dial indicator position to give me a better idea of what between C and H was telling me.. midrange was bout right at 200F your results may vary..