# GTO running hot... sometimes.



## LS2_STS (Jan 5, 2012)

2006 GTO LS2.

A few months ago I came here with some overheating issues. I was told to flush the coolant and change the thermostat before I tried more extreme measures. I took the advice and did both of those, replacing it with the factory temperature thermostat and flushed the entire coolant system. (Also had to replace the mass air flow sensor)

Now the car was fine for a little bit, but now on occasions (not all the time), in traffic, the car wants to start heating up again. The temperature needle will start to climb, sometimes in the red, triggering the chimes and what not to say its overheating. Then almost immediatly the system will flush and the temperature will plummet back to normal.

So I am pretty much at a loss at this point, so I have the car at the mechanic now getting inspected and what not, so I told him to take a look to see if he can solve the problem. He called me today and said he has had the car running for about an hour, just sitting and a few trips up and down the road and he said the temperature is not budging, no overheating. He said the fans are kicking on at the correct times and the system is flushing as normal. He said the water pump is also in good working order and the thermostat appears to be in good shape. He doesnt know what it could be.

Now this is where you guys come in, what route should I go now? It happens at all outside temperatures and at random times. Should I try replacing the thermostat yet again, just to do it to see if the replacement is also sticking? Any ideas? Only aftermarket mods are K&N Intake and a spintech exhaust, the motor is stock.

Thanks.


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## B-ville Goat (Oct 5, 2008)

If it acted like that chances are you had an air bubble working it's way out, that's about the only thing that could "fix" itself.


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## soltino (Sep 12, 2006)

"the system flushes"

please explain

tino


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## Rukee (Feb 8, 2007)

When it's getting hot are the fans working?


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## LS2_STS (Jan 5, 2012)

I doubt its an air bubble if its been going on for over a week at random times. I mentioned that the fans are kicking on at the correct time. When I say the system flushes, I mean you can tell when the coolant dumps because the temperature will immediately shoot down to the correct level.


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## 68OldGoat (Nov 23, 2009)

I agree with the air bubble theory as the problem since after the car flushes it seems to be OK for awhile and then comes back.The problem might be coming back because the system continues to be sucking air from a small leak in the cooling system to create another air bubble. The other thought is that someplace in the engine there is a blockage in some part of the internal cooling jacket. Have you tried changing the temp sensor sending unit?


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## EagleGoat (Jun 6, 2012)

When you changed the stat had you ever burped a cooling system before? It's not always easy in these cars. You could alsways do a cooler stat to get it opening soon, but that may be masking the problem and not fixing it. Btw, you have a very honest and mechanic, so even if he isn't the best, ie your disagreeing with him about this, that's a pretty good trade off IMHO.


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