Overheating

[ruberpoliceman]

New thermostat, new head gaskets, new water pump and fan clutch. After replacing these the car ran fine without overheating for about 50 miles then it overheated again. It seems as if the coolant is not flowing properly. When everything was first replaced the radiator was removed and flushed and i noticed a lot of sediments being removed also there looks as if the inside holds heavy water deposits but water still flowed fine as far as i could tell bringing me back to the part about riding fine for 50 or so miles trouble free. My assumption would be that the radiator is possibly clogged not allowing coolant to flow as it should but was wondering if any of you guys may have ran into a similar problem and would know any other possible cause to my overheating situation....

its an 86' caprice civi 305

[silicon212]

Radiator.

Just because "it flowed well" does not mean that 2/3 of the core is flowable. It may well be OK to a point, but has lost its efficiency. Get it rodded out or replaced, and see if that helps. Another thing you might be experiencing is a restricted exhaust - possibly a plugged cat. Does the power fall off at highway speeds? Does it seem like it loses its breath where it should be doing fine?

[ruberpoliceman]

The cat is removed....the exhaust was just re-done so thats out. Im really leaning towards just replacing the radiator. And yes it runs fine at all speeds in any conditions it just overheats after about 10 to 15 minutes of driving then does the whole spark knock and shuts down.


By the way i really like that red and black paint skeem you got there, what kind of springs do you have? or are there supports? i noticed it sits up nice.

[bobss396]

Thanks for posting the new thread. I agree on the radiator.

You never know what was put into an old radiator, IMHO, Barrs stop leak was great for clogging up a marginal radiator or heater core. Also it might have been fixed a couple of times.

New radiators are amazingly cheap, when I have a suspect one, I chuck it and get a new one. The last one I got was for my '79 Caprice, ran like $105.

Bob

[inafogg]

not sure on your car but check to make sure its not just air trapped or some thing like a callasped hose good luck

[silicon212]

Originally Posted by ruberpoliceman

The cat is removed....the exhaust was just re-done so thats out. Im really leaning towards just replacing the radiator. And yes it runs fine at all speeds in any conditions it just overheats after about 10 to 15 minutes of driving then does the whole spark knock and shuts down.


By the way i really like that red and black paint skeem you got there, what kind of springs do you have? or are there supports? i noticed it sits up nice.

Thanks for the compliment on the paint scheme. There will be more done to it - more black will be added to the top surfaces - hood, top, decklid and there will be wide red stripes in the black.

The front springs are from Checker Auto Parts, heavy duty replacement springs. The Checker (CSK, Checker/Schucks/Kragen/PartsAmerica.com) HD springs are actually 9C1 spec springs. The rear springs are RJ factory springs (8RJ, 9RJ).