Hi,

I have a 67 Cutlass S with a 425, th400, and big block quadrajet. After driving the car for about 10 mins, it gets extremely hot and, in extreme conditions, even smokes a little out of the exhaust pipes.

Here are some of the things that I think could be wrong from my research so far, if you could let me know what you think about them then that would be so helpful.

I do not have a fan cover (Not enough air circulating?)

The anti-freeze is about 3 inches down in the radiator and it looks like there might be a very very slight leak

I cannot turn the fan by hand (Possibly the belts are too tight?)

Radiator is no good (Clogged, damaged, not correct to the engine?)

I also know it could be the thermostat, I just wanted to try the easier stuff first and work my way through to the other stuff. Eventually I will try it all if I have to!
Thanks again!

 

If closed system, no over flow tank, the anti-freeze level should be a couple inches below the neck to allow for expansion. Look on the passenger side of the radiator that faces the engine. You should see a fill here mark.

For giggles, starting with a cool engine, try to start it up with the radiator cap off. If it blows water out, then you might have a head gasket or cracked head problem.

Pull your thermostat and try boiling it in a pot of water to see if it opens...

I am sure there are more ideas.

Just saw that you cannot turn your fan by hand. Did I read that right? You should be able to turn it by hand assuming you have a fan clutch.

 

How hot is it getting?

- Eric

 

Thermo not opening would be my first guess..You should be able to turn your fan by hand. Also a fan shroud missing will cause way higher temps but not high enough to really overheat unless you are in some real hot weather in standing traffic

 

My 1st guess would be a 425 swap using the old junky 330 radiator. If the radiator is not a 3 row minimum or looks old I would replace it.

 

 

I will try to get more exact temperatures and pictures on tonight. I always thought it was a bad radiator but everyone seems to have a different suggestion on what the problem could be.

I really have no solid evidence that it is overheating but I just firmly believe that it is due to how it is acting. Plus it smokes after awhile from where the exhaust connects to the engine. Ill go out and run/drive it tomorrow though to be able to get more accurate info and temps.

I never heard about a fixed fan, I just knew that some people said that if you cannot turn the fan by hand then you could be in trouble.

 

I don't see how anyone can make a suggestion not knowing what temp its reaching. You description is basically saying, "it's broke? Whats wrong?".

The smoke in your engine compartment may be an oil leak. Post a picture of your fan and radiator. You can buy an inexpensive temperature gauge at the auto parts store, hook it up temporarily or permanently, your choice. Either way you'll have an idea what temps your engine is running.

 

Seriously?



So, valve cover gaskets ooze oil, oil obeys law of gravity and flows downward, onto exhaust manifolds, engine starts, manifolds get hot, oil burns off.

It's not a bug. It's a feature.



And if you had a clutch fan that was completely locked up, then, logically, it would be turning at its maximum possible speed all of the time, and it would be drawing the maximum amount of air possible through the radiator, which would provide the maximum possible amount of cooling.

Right?


This may sound bad, but you will do much better with your car if you sit down and think these things through before you start fretting about them.

- Eric

 

Starting with a cold engine, fire it up with the radiator cap off. If it pushes coolant up immediately you probably have a head gasket blown.
If all is well keep your hand on top of the radiator, after a few minutes it should get hot as the thermostat opens. If it doesnt but water strts rising up the radiator and the bottom hose is warm the thermostat is stickking shut. Replace it.
When the thermostat opens the radiator should warm up everywhere from the top down. If you can feel parts cooler than the rest your radiator is plugged. Replace or recore it.

That's about as much as you can do without a temperature gauge.
While this is going on look for the source of any smoke/steam and oil or water leaks.

Overheating soon after startup is normally a thermostat or gasket problem, a clogged radiator would take a while before it couldn't cope anymore.

Roger.