I thought so too, but it looks very good. If it's cracked it's somewhere internal where you can't see it. The heads and the oil cooler (with the distribution housing it sits on) goes off to an engine shop tomorrow for analysis.

The oil in the inlet is because the increased oil volume made the oil tank overflow through the breather pipe between the tank and the intake. The left side turbo hose is located lower than the right side one, that's why the oil only spilled down on one side. It did not come from the exhaust side so that doesn't narrow it down to one specific bank.

That was my primary suspect before ripping it all into atoms. But we tested it thoroughly. The water passages were pressurized to 2 bars and it held for hours. The test was done with the oil cooler mounted to the casting. There's only one in and one out, unlike the oil which goes everywhere. So it was pretty easy to test. No result though. It could change when things get hot, but... We'll see, it's off for analysis as well so.

 

Sorry for your troubles, I recently went through the same problem on a 997tt after pushing on A28's: water in oil but no oil in the coolant, car ran great I only noticed when changing the oil.

After complete teardown everything seemed in order, HG not blown, coolers tested fine, so did the heads and cylinder cases. Before we opened the engine I did notice oil/coolant stains under the engine at the head/water jacket area (engine case was washed and degreased a few days earlier) ... So the theory is it was slowly leaking at the HG level as opposed to a blown gasket ...

Bearings came out surprisingly mint, so it couldn't be going on for too long .... Threw in a new set with new rods and headstuds, everything left stock including pistons, heads (not even ported) and cam, wanted the car to feel and drive just like stock .... Been about 700km since the build @ 1.0-1.3 bar most of the time problem gone .....

Good luck

 

What I believe happens here is that the head studs fatigue after a while of running 20 psi on them and they lift. The cylinder pressure gets around the firing ring and blasts into the water jacket. The cylinder liners have orings on either side of the jacket and the pressure blasts the water around the bottom orings and into the motor. In my case I had a cylinder that was drinking coolant. After a long run through 5th the water got blasted around the jacket and into my cylinder causing my motor to hydrolock.

You have 2 options here. One is that you can buy a replacement motor and sell your parts, but then you are still running the same risks as before. Your crank and pistons might be bad but you can get good money for your parts. Case $2000, heads 1k each so $2000, housings $500, maybe $1500 more for other stuff.

Option 2 is that you can get a used good crank and rebuild with a 3.8 kit, rods, and good head studs. It would cost more in the end but then you can wail on the thing with no issues.

 

So no root cause yet?

 

His heads lifted and the cylinder pressure blasted water through the bottom of the jacket oring...

 

Didn't see him post that info

 

Big mess... I“m sorry for you! Never though the coolant tank could be so clean after that...

 

I think the lifted head is the only explanation left. When at low cylinder pressure when just driving around the studs still cinch down on the head gasket enough to seal it off. That's why it passed the coolant pressure test. It isn't doing it enough to discolor the coolant either. You would think that it would show signs on the head gasket, but my HG looked fine when I pulled it out also. It is more a head stud failure than a head gasket failure so it doesn't blow the HG out the side like a V8 or other typical HG failure that leaks all the time.

 

As others suspected, I would say this is a sure sign of a failed head gasket. It's possible that it failed between cylinders and is only showing issues under boost when it is pushing coolant. Good luck.

 

Talked to the engine testing shop yesterday, they hadn't had time to check the stuff out yet. They would get around to it this week. I'll keep you guys updated.

 

Got the results today (and a 718 usd bill)...

Pressure tested oil cooler to 1,2 bar. No cracks or leaks.
Pressure tested heads to 1,5 bar. No cracks or leaks.


So that was another dead end.

 

Measure the studs for stretch

 

Does anyone have link to pictorials or information on how the metzger cylinders / seals are setup? I know may way around a traditional engine block but not familiar with the architecture of the metzger cylinders.

 

its in the repair /service manual

 

Finally got around to poking some more and found the culprit. Someone has at sometime had the engine apart (markings on heads and on pistons indicating placement for reassembly). When reinstalling the liners they've managed to either twist it or otherwise damage the top of the two bottom o-rings. When the bottom of the two failed it allowed water to seap down into the sump from cylinder 2. Cyl 5 was also less than perfect, the other two were ok. New o-rings ordered.

Glad to finally find a proper fault and eager to get it back on the road.