:Updated: Confirming blown head gasket :Updated:

[free_couch]

My supra has been doing things that made me think I'v had a head gasket problem for a while now, I always seem to have air in the system (waterfall noise) and sometimes my coolant level drops really low. I decided to do a compression and leakdown test. My compression results were 170,170,182,175,180,180 which seems ok to me. I don't have a leakdown tester so I just hooked up a compressor set to 90 psi straight to each cylinder (set to tdc) and on every one except # 6, the coolant level started to rise, no bubbles, just overflowing. So my question is am I looking at a basic head gasket change or do I have a more serious problem like a warped or cracked head or block?

Additional Info:

When I bought the car I was told that the engine has a metal head gasket with ARP studs torqued to 80 ft. lbs

Update:

I finished pulling the head yesterday, here's what I found. As far as I can tell the head gasket looked ok. Cylinders 3, 5 and 6 had excessive oil and carbon build up on the pistons and valves. I'm hoping it's just the valve guides but it looks really bad, might be the rings. I checked the head and block for warping and found the block to be ok, but the head is slightly warped. The head also seems to have been surfaced by a hand sander/grinder, not by a machine shop which along with the warping would explain the leak down test making the coolant rise. I’m will be taking the head to a machine shop in a couple of days, considering pulling the block.

Here are links to some pictures:
cylinders 1-3 http://www.flickr.com/photos/61419666@N06/5590287151/
cylinders 4-6 http://www.flickr.com/photos/61419666@N06/5590288759/
valves 1-2 http://www.flickr.com/photos/61419666@N06/5590872730/
valves 3-4 http://www.flickr.com/photos/61419666@N06/5590281735/
valves 5-6 http://www.flickr.com/photos/61419666@N06/5590867560/

 

[Compton74]

i think your coolant level rises due to the fact your pressurising the system(someone correct me if im wrong). But my car also to had the waterfall noise, and i just jacked the car up as high as possible ran it and filled coolant accordingly. But are their any tell tale signs of BHG, such as milky oil under cap, bubbles out of the overflow?

 

[free_couch]

There doest seem to be any of the tell tale signs, I have tried burping the cooling system by jacking up the car and letting it run with the heater on but the waterfall noise always came back (not sure if it ever entirely went away). The car seems to run great, it has only overheated once on me and that was a couple of years ago.

 

[radiod]

Waterfall noises aren't necessarily a blown head gasket, just a coolant leak. You could have a tiny pin hole leak or hose that's just barely not tight enough that you don't even see drips on the ground. Check inside your overflow and see if there's oil in your coolant and/or crack the oil drain plug after the cars been sitting a couple hours and see if the first bit that comes out is coolant.

As far as cracked head/block, there's no easy way of telling until it's ripped apart. If it is a problem though it will more likely be a cracked head than a block though due to the fact that the head is alluminum. If the alluminum gets exposed to higher than normal temperatures it can start annealing and softening. I pulled mine off to find that there were 3 visible cracks in the head, but I also had receipts for 3 head gasket jobs (last of which was an HKS MHG w/ ARP studs) when I bought it and the car had around 200,000 miles on it.

 

[zambini]

look around the engine bay closely for white specs of baked coolant.

 

[digihonk82]

You should look into a BHG tester. It looks at the coolant quality/analyzes for combustion gasses...Or you could just get it fully warmed up and romp on it a bunch. Maybe then the problem will really come to light as white smoke from the tailpipe.

 

[OfnaRcR4]

Waterfall noises aren't necessarily a blown head gasket, just a coolant leak. You could have a tiny pin hole leak or hose that's just barely not tight enough that you don't even see drips on the ground. Check inside your overflow and see if there's oil in your coolant and/or crack the oil drain plug after the cars been sitting a couple hours and see if the first bit that comes out is coolant.

As far as cracked head/block, there's no easy way of telling until it's ripped apart. If it is a problem though it will more likely be a cracked head than a block though due to the fact that the head is alluminum. If the alluminum gets exposed to higher than normal temperatures it can start annealing and softening. I pulled mine off to find that there were 3 visible cracks in the head, but I also had receipts for 3 head gasket jobs (last of which was an HKS MHG w/ ARP studs) when I bought it and the car had around 200,000 miles on it.

Exactly. Mine has a nice waterfall after I start it up but its because my turbo is missing a gasket on the block off.

 

[free_couch]

So after doing some research and asking around, my best guess is that the head gasket was installed incorrectly. I'm going to pull the head tomorrow, I'll post what I find. I thought about getting the BHG tester but the fact that a leak down test forces air into the radiator tells me something is wrong. Because this happens on each cylinder I'm guessing that mistakes were made by the previous installer. I'll find out soon enough.

 

[bluepearl]

^^^^^ I was going to post this, but you got it figured out. There is leakage thou, you can bet on it.

 

[SupraSean]

Thread jack- What about coolant overflowing the reservoir after the car has been shut off. only does it sometimes. no smoke once fully warm, no milk under the cap. no oil in coolant. never gets hot. any idea's?

 

[free_couch]

just updated my post, look above