180/170/150/210 Compression and Oil Leak

Manerd05

Manerd05

Greenie N00B Member
Apologies if this has been posted before, I've searched quite a bit and can't find anything on it.

A few months ago I purchased a 07 Speed3 with 130k miles on it.

Recently, it started throwing white smoke out of the exhaust, which we believe is the result of the turbo seals failing and letting a substantial amount of oil through the intercooler and into the engine intake (Enough to puddle up/Completely coat the tube).

A few days ago when I was driving, the car started misfiring and was struggling to idle, so we checked the spark plugs (Which are completely black) and did a compression test, which turned out to be 180/170/150/210. What would cause such an extreme pressure difference from cylinders 3 to 4?

The car behaves normally until it gets warmed up, where it then starts to misfire and struggles to idle.

Is there any way that these issues could be related? What are some potential causes?

Thanks for the help!
 
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Low compression on cyl 3 is notorious. Could an issue with the rings. Try doing a wet test and see if the compression comes up. As for high comp on cyl 4, could be carbon.

You can also try a top end soak with X66P. @MS3brohanna did that in her old car, and it actually restored compression. @HawkeyeGeoff has a write up on how to do it somewhere. But she never had the driveability issues you did.

Make sure the plugs are capped to like .028 or lower. Any stored codes? Can you check long term fuel trims at idle?
 
@mangosmoothie Thanks for the feedback! X66P soak is a good idea and I will likely try that eventually, but i'm trying to figure out some other issues first.

The plugs are gapped correctly, but are completely fouled, despite them only being three months old. It has been throwing a p2188 (Too rich at idle) code.

When I initially ran into the stuttering/bucking issue it was at night, and I didnt notice that the exhaust has been shooting out a huge amount of white smoke, which leads me to believe that my turbo seal has gone.

I replaced the PCV valve and cleaned out the intake manifold and intercooler, which initially appeared to solve the problem, but a few days later it returned to the stuttering/bucking and exhaust smoking behaviour.

I'm not sure where to go from here... I will try recording fuel trims and reporting back
 
This is what you are looking for. I will make a thread for this as I have done this procedure and it did help a bit.

  1. Get the car hot then let take out the plugs.
  2. Pour 4oz into each cylinder
  3. Let it sit overnight or a day or two.
  4. Suck out the fluid from each cyl.
  5. Change your oil as it will seep into it, do some cheapo oil.
  6. Drive the car for 50ish mile with decent revving and engine braking, similar to a motor break in.
  7. Change the oil to the good stuff and then check compression when you get a chance.

ACDelco X66P Fuel Injector and Upper Engine Cleaner - 16 oz
 
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