89 vette overheats after 10 minutes????????

[nelson84]

What would cause a 89 vette to overheat after 10 minutes? It runs fine for ten minutes and then suddenly starts to over heat???? Why would that happen?

theromstat?

The reason I am asking is because a guy is selling it and he doesn't know why either?

What causes over heating?

[vetteboy86]

Thermostat would be the first place I would look. How is the rest of the cooling system....water pump, radiator, coolant, and cooling fan?

[ejrempel]

Are the front and rear fans going on? No fans means overheating.

[johnny80]

I had similar problems with my 88. Realized that the fan was not kicking on after 180 degrees. Thought I had to replace the entire fan housing and motor, just realized that it was the motor. The check that I did was turn on the AC and see if the fan kicks on. if the fan does not start, simply replace the motor, only about 40.00 at a any auto part store. Pretty easy fix and now she runs great, never gets hot. Do you have dual fans on a 84?

[rel3rd]

Define your view of OVERHEATING please.

In 10 minutes, it's almost impossible to be overheating already.
Are you going by the gauge reading?

I'd suspect an air pocket in cooling system causing bogus readings.

[WradDad]

I would agree with the air pocket idea. I've had that happen to me after I've dumped and refilled the cooling system. Does the temp spike very rapidly? If so, then the cooling system just needs to have the air bled out of it. There's an air bleed screw on the thermostat housing of my '96. Just crack that open until water starts coming out then close it up. You might need to do it a couple times to get all the air.

Barry

[89sleeper]

What are the high temps you are getting???
I have a 89 vert with 10,000 actual miles on it this car reaches 221 degress before the cooling fans turn on then the temp begins dropping at that time (this is perfectly normal) it also has a 195 degree thermostat from the factory
Ten minutes does sound a little fast from a cold start to over heat conditions

[Hot Rod Roy]

Is he selling the car because he can't figure out why it overheats? If so, he's probably tried all the easy things. That's a pretty serious decision to sell the car because you can't find the problem!! Let some sucker fight it for a while?? Can he show you receipts of the work done to try solving the problem? Could be serious trouble! He might know the problem, but doesn't want to tell you.

[Notorious]

Originally Posted by rel3rd

In 10 minutes, it's almost impossible to be overheating already.

Not if there's compression leaking in the cooling system. Put a pressure tester on it and tell me how much pressure it's building and in what amount of time.

[rel3rd]

Originally Posted by Notorious

Not if there's compression leaking in the cooling system. Put a pressure tester on it and tell me how much pressure it's building and in what amount of time.

That's where the "almost" comes into play...