shiners780

There's no oil in the coolant, or coolant in the oil that I can tell. There are tiny black particles in the coolant reservoir however.

The coolant level dropped a little bit.

I had an issue recently with the stock temperature gauge rising while the car was at idle, and the coolant overflowed a couple times. I thought maybe I had air in the cooling system, so I pressure tested the system and bled the air out.

In addition to using the pressure tester, while the car was idling, I opened the coolant bleed valve on the top of the block and air would come out for at least 5 minutes! Just steam and air, no coolant.

A couple times after a track session, the coolant level would be really low in the reservoir. If I cracked open the cap on the reservoir, coolant would surge back into the reservoir. It usually returned to it's normal level, but the last time it returned lower than normal (after cooling down.)

Occasionally, when the engine was warm, I would get only 5-6 pounds of boost on an aftermarket gauge, when normally I see 14-15 pounds (Autothority Stage II chips, no aftermarket boost controller, stock AFM, stock wastegate, stock turbo). Once the car cooled and I went back out, the boost would be fine. This lower boost reading happened a couple times.

No white smoke out tailpipe, or coolant smell from the exhaust that I could tell.

So...is this a headgasket issue? Anything else it could be?

MPD47

Just taking a swing at it here, but it sounds like you've pushed the gasket out a bit and you're burning a very small amount of coolant at the time, the gasket is toast but is just barely holding together. You're pushing pressure into the coolant system under boost and burning coolant at idle. But that's just my guess. It HAS to be going somewhere, and if it's not going into the oil, or leaking everywhere, that's likely where it's going.

So you've done one "my way" (aka not the standard 944 way, of course). And not ripped through it mixing fluids.

shiners780

Hey Mike, I left a message on your answering machine.

So what's causing all the air in the cooling system?

billthe3

The compression of the cylinder is forcing air out of the cylinder into the cooling system.

Mine was doing the same thing. I realized how bad it was when I turned the car off and quickly ran up to check the coolant level, and a ton of air bubbles started flowing up through the cooling system.

MPD47

*Goes to check answering machine*

Geneqco

You can do a simple test for presence of CO2 coming from yourt cooling system while the car is running to confrim this.

shiners780

Oh yay! So now that I've joined the Blown Headgasket Club, is there a secret handshake or something that I need to know?

ehall

There is. But...it's a secret! lol

Sorry to hear this man. It appears to be like pregnancy in an office, sometimes it's just in the water.

shiners780

Yeah, it appears I'm not alone. I guess it's true that misery loves company.

I should have done it over the winter when I had everything off to rebuild the turbo.

Chris White

Looks like shiners780 is out of the headgasket club….
After reading the post and talking with Jim it didn’t sound like a headgasket so I recommended pressurizing the coolant system and leaving it for a while @ 18 psi.
Looks like hose leaks!
So – don’t show him the secret handshake yet….

shiners780

Thank you Chris for giving me hope. This is what I've found so far:

I pressurized the cooling system to 12 psi, no leaks. I pressurized it to 16 psi, and I got leaks.

1. Leak #1 is coming out the driver's side hole under the radiator, not sure what it's called, support bracket maybe? So it appears the radiator may have a small leak. It drips very slowly, maybe one drip per minute at 16 psi.

2. Leak #2 comes out the rear end of the hard pipe that runs over the exhaust manifold. I put a heater delete hose on over the winter, and I guess I need a new hose clamp because I can't turn it any tighter and it leaks A LOT at 16 psi, like running out.

3. Leak #3 is pictured below on the waterpump. I can't tell if it's coming from the waterpump itself, the waterpump seal, or...is the headgasket right in that vicinity as well? Can you tell anything from this picture?

I have never seen any sign of coolant on my garage floor, so it appears the leaks are only occuring while the car is being driven and the system is under pressure. Any coolant leaks probably evaporated/burned off, leaving no puddles.

I can understand how all these leaks would account for the coolant loss, but would these leaks also account for all the air in the cooling system?

xsboost90

yup- remember if coolant can come out, air can come in- its an open door.

ehall

I'm (from personal experience) going to reccomend to anyone reading this thread, to get a Stant pressure tester, either new or from ebay, to use when testing, changing or in anyway messing with the coolant system on our cars. If you haven't done so, put the system under pressure and you'll be shocked what you will find.

shiners780

^ Yeah, the pressure tester is super helpful. I got mine on eBay for $45.

OK, Leak #2 on the hardpipe to heater delete hose is fixed, of course that was the easy one.

I'm not sure how to find Leak #1 from under the radiator. Will I need to pull the radiator and have it tested?

Leak #3: I wiped everything off, then pressurized the system again. I looked closely above/around the waterpump and the leak appears to be coming from just behind and above the waterpump, see pic -- taken from the top right next to the oil filter: (wireless mouses suck for writing)

billthe3

If that is the header bolt in the top center of that picture, I have a feeling that would be more a head leak than a waterpump leak.

To get a better picture, hold the camera out farther so it will be able to focus correctly. Then just trim the picture and possibly zoom in when you've got it on the computer.