Well I haven't purged the cooling system on the car in a while..taking daughter to school this morning the car overheated..shut it off immediately and wife came with ramps, coolant funnel and purged it and it ran like a champ on the way home. So what I want to do now is hook up a pressure gauge to the cooling system that I can see while driving and run it up into boost and see what happens. Maybe there is a gasket leak only seen at operating temp and only in boost. Haven't had any problems for 2 months since I reinstalled the thermostat.

Car's cooling system held 13psi for 20 minutes doing a pressure check.
One way I thought of doing this is using the same tool but would have to put the car on a dyno to use it...I want to do it while driving...

Anyone ever done this and if so what did you use?

There are NO indications of a head gasket leak..neither the oil or coolant is contaminated and I have performed a coolant gas contamination test already...

So either my theory is true about the water pump cavitating and causing air bubbles that end up behind the thermostat or I have a small leak that is only happening at operating temp and only on boost.

Discuss...

 

I am so confused on the whole coolant purge. I know a lot of people here do it and have success, but how is air getting into the system?

 

have you kept an eye on the coolant level in the overflow tank and kept it at an appropriate level since the last purge?

coolant level will go down over time and if there is not enough in the overflow you wil suck air in

I never purge mine since the engine swap and no issues

 

Your wife came and brought you ramps, and purged your coolant on the side of the road while your daughter watched mommy be a hero?
You might be on to something with the dyno thing. at least you could have the hood popped and try to figure it out.
My coolant does the whole overflow thing, but my car has never overheated as a result. It did overflow on the dyno, shot about 2 feet out of the little pisshole in the aps overflow can.
Is it leaking(smell coolant) as the temp starts to spike? or is it just out of the blue?
I've learned to accept it, I just top it off every few weeks. You sound like you might have something a little more serious going on, but then again, it was 30 degrees on the way to work today. You?

 

yup!!!! that's what happened to me. I haddened paid attention to my overflow cnaister for a long time. I had noticed that it was usually dry, but I never filled cause there never seemed to be an issue...........finally, I guess I got enough air in the system and my car overheated a few weeks ago.

I refilled the system, cycled it several times and made sure that all the air was out of there. I have been fine for the last 3 weeks.

 

What I think happens with most Greddy kits is the tube is too long, and bends up and over, out of the coolant. Then it sucks air back in that way....