Ok, so I just got my car back driving and have a jb6262 on a stock 2005 with roughly 40,000 miles. During some manifold / creep testing (was having creep issues that peaked at ~10.5psi) the motor saw way too much pressure. I have the AEM series II, with boost fuel cut set to 10.8psi (the max of the oem map sensor). It did not cut at all, which I am thinking it didn't possibly because the map never put that value out. Maybe my map sensor "quits" at 10.6....I don't know. The overboost was a wastegate line issue, which is 100% my fault.


The car still runs and drives...it feels normal for the most part in boost and out of it. Air fuel ratio is good and consistent. Timing at 9psi is around 14 degrees. The problem I think I have now is oil in the cylinders. When pulling the plugs for testing, I looked at the tops of the pistons and they were a little wet. The car does not visibly burn any oil, but I can only see so much when I'm driving.


So I check the compression/leakdown after coming home from work to try and diagnose anything I can.

1 245 8%
2 242 6%
3 239 6%
4 247 4%

The numbers themselves don't look too bad. Obviously I would like the leakdown to be lower, but it is what it is. When the cylinder is pressurized, I can feel/hear/smell the air pushing through the larger valve cover vent. I have a feeling it could be piston rings, not sure if it may be just a headgasket. I need to do a cold leakdown and see if I'm pushing coolant, although driving it around does not effect coolant levels or raise coolant temps too high. I am also going to get a scope and take a look into the cylinders before I pull the head (if it gets to that point).

Also wanted to verify the leakdown process. I am charging the cylinder, valves closed, with a regulated air pressure of 100psi. Once connected to the cylinder, I count the current pressure on the regulator and get my percentage from that. So 100psi dropping to 95psi is 5%. This is the way I understand of doing this...but I don't leakdown things too often.

Lastly, the blowby smell is pretty obvious. More so than before the incident. The vents are just open right now, I haven't made a catch can setup yet. Do you guys experience a decent amount of blowby? Obviously mine shows through my leakdown numbers, but notice I can smell them at a stop, or especially with the hvac pulling in outside air (also just at a stop).

So my main concern is chasing the oil leak onto the pistons. All pistons have some degree of wetness, but the plugs don't look too bad/fouled out. I am wondering if the knock that did happen, managed to effect my valves/seals as well. I don't know...any direction would be nice.

 

Sounds like you had boost cut set higher than what the map sensor could read. Do you have any logs? Did map just flatline?

 

I agree with the cut being higher than the max. I will post the log when I get home from work.

I am pretty sure that yes, the map pressure flatlined, and the high knock lasted for .5 seconds.

Right now I am not expecting great news.

 

So here is the log of when it happened. It is off the ecu and I copied the image when it started recording.

Rollercoaster of knock.





I also saw some saturation on the block, right below the head. I can only assume it is oil, but either way I'm going to take the head off to get a better look.

Best case its just the gasket. Worst case.....well...a lot more money than just the gasket. We will see.









Also tested the boost cut at 5psi. It does work, and definitely did not engage any time before. I have a 3 bar sensor thats going to go on the car, so this time I will set the cut under the max pressure read, by a decent amount.

 

I was able to get a camera into the cylinders today. It doesn't look good.

Piston #2 appears to be cracked.

http://youtu.be/PrujAt4I03g