Need help quick-2002 impala

[freeflow]

Hey guys here is the problem we are having with my dads 2002 impala with the 3.4. About a week ago the old man said it started blowing cold air out of the vents after blowing hot air- the hot would fade in and out, and the car started to go up close to overheating a few times.

So this is what i have done so far, flushed the radiator 2 times and refilled and did the heater on high to get the air out of the system shutting the motor off several times-seemed to be working ok last sunday last time i drove/looked at it. But he just asked me today if i can help him with replacing the thermostat this weekend so the problem must still be there.

O ya the car has 76,000 on it- and had a profesional flush about a year and a half ago.

Any ideas??- anybody had similar problems??

Thanks brad

 

[pauly383]

We have a 2003 , and did finally have a cooling system problem . Right after the warranty was up , the passenger side fan went out .

Don't know if it would be your problem , but at least make sure the fans are both spinning .

First line past half on the gauge is when both fans low should start , and when a/c is on , or it gets to 240 degrees , both fans should be on high .

 

[80' 427]

I would sure check the thermostat. The only other problem they ever have is a lower intake coolant leak that may drop the coolant level and cause poor heating. But if you did a cooling system flush I would guess it is thermostat time.

 

[broke73]

I would look in the coolant reservoir and see if it looks like there is oil in it. On the 3.4 I would expect it to be the Intake gasket these go bad all the time. If you open the bleeder and you get air out of the cooling system it is a good indication that the gasket is bad. The reason it causes the car to over heat is that air gets trapped in the system and causes the thermostat to get stuck. You can try replacing the T-stat but if it continues to overheat change the intake gasket.

 

[80' 427]

U are right we did 3 of those intakes this week and we are slow. they leak all the time. If it is the intake felpro is making a better gasket that should fit it for a long time.

 

[freeflow]

Well i got the throttle body taken off and the thermostat out and the old one looks in good shape. Now about that intake gasket i was looking at the driver side behind where the thermostat is located and there are a few drops of what looks like coolant on the block right under where the gasket is in between the intake and the heads. Is that the gasket that fails???

thanks brad

 

[broke73]

If it has failed there it's probably worse under the intake, but you won't be able to see that until you get the intake off. Not to bad of a job just take your time.