PedalMaxer

I wont try this unless someone who knows tells me it is safe, but I was thinking about just running open for about 1min. The steam/coolant usually starts right away, that would narrow it down to the correct cylinder, but I guess that still wont tell me exactly what the damage is.

Slakker

I would recommend doing as Jake asks if he is going to take the time to help you troubleshoot.

FYI, if you are using your phone you will need to upload pics via your phone browser as the app tends to bomb out.

PedalMaxer

I may have misunderstood his instructions. I thought he wanted pics after I unbolted the exhaust, but I cant see in well. Here is an example of the best pic I could get of 6.



Below are pics of the wet exhaust bolt and its hole between 5 and 6.

PedalMaxer

I got the exhaust out and it looks like the moisture is only coming from cylinder 5. Here is a pic showing the wetness. It is totally wet like that all the way to where both exhaust valves seat.




Also, the valve stems look whiteish like they have been steamed on cylinder 5 (pictured below). The color is a little hard to see in the pics




4 and 6 are pictured below respectively for comparison.

Flat6 Innovations

Thats not as wet as I'd expect. Typically the pencil sized holes will drip coolant if a 3 chain head is cracked internally.

I see moisture in the #5 exhaust, and at this point that's pointing toward a cracked cylinder. The good news is, thats its not horrible yet. Definitely do not run it anymore, and get it to an M96 Specialist. If the cylinder cracks too far the chunk will break away, and thats a massive failure.

I'd pressurize the cooling system without the engine running, and see what happens. Roll the engine over so the exhaust valves on cylinder 5 are open, pressurize the system, and wait for the show.

Stephen Tinker

This gold nugget advice from Raby is worth a lot of money - just think how much a shop would have charged for it, even if you had taken off the exhaust manifold yourself.....

PedalMaxer

Thanks Jake. I pressurized the system to 20psi, but the cap vented it down to just under 15psi. After a few minutes water started to come out from one of the open exhaust valves in cylinder 5. It is dripping at a rate of one drip every 4 seconds. I can not even really see a change in PSI after over 30min (still almost 15PSI), maybe 1/4 PSI loss. This must be why I thought it was passing a pressure test earlier.

So does this confirm a cracked cylinder wall and not a cracked head? Thanks again Jake

Flat6 Innovations

This is further confirmation of a cracked cylinder. There's a 1 in 10,000 chance the head gasket failed, but I'd bet against it.

Come get in line!

PedalMaxer

Thanks for everyone's help on this. I really appreciate the professional diagnosis Jake. This engine is totally original at 106k miles, so it wont hurt to have an expert go through it anyway.

Flat6 Innovations

If you re going to have a failure, cylinder failure via a crack is the one to have.. Not catastrophic and collateral damages are limited to maybe an O2 sensor.

So much better than this!

Schnell Gelb

wow - even the thrust washer was dislodged?

Flat6 Innovations

Actually, the thrust shim was the primary failure.

It was a reman Factory engine and the shim was installed backward. When this occurs the oiling grooves face the carrier and not the crankshaft, so the surfaces do not get enough oil. The lack of lubrication makes for more friction. As the thrust shim wears it becomes thinner and eventually will fall out like this one has.

Actually the thrust shim pictures was installed correctly, but the second one on the opposite side of the carrier was at fault first. It's the one that was installed backward, as there's no signs of wear on the inboard side, but a ton on the outboard.

This is the 5th time I have documented this mode of failure.

Schnell Gelb

Thank you for the explanation. The devil is in the details !