[Starrdrop]

Hey all, I figured I should just start a new thread about this car. Yes, I've still got it. I'm trying to diagnose it so it's easier to sell or possibly repair, if the price isn't too high. I bought the car for $3800, and with everything so far I'm about $5000 in. Any and all help is great, from explanations on how to fix things or links to the correct parts.

The issues it (still) has are:

P0302: Cylinder 2 Misfire
P0304: Cylinder 4 Misfire (coil replaced ~10k miles ago)
P0306: Cylinder 6 Misfire
P2270: O2 Sensor Signal Stuck Lean - Bank 1, Sensor 2 (mechanic claims both O2 sensors are not attached)
P0420: Catalyst System Efficiency Below Threshold (the car is straight-piped)
P074468: Torque Converter Clutch Solenoid Circuit Intermittent. Algorithm-Based Failures (probably throwing a code due to engine misfire) (NOTE: Codes have not been read since CEL returned due to continued misfiring, this code may still be present)

• Turbo is leaking from at least the oil return gasket (I can't find the correct part, if someone could find it let me know!)
• Mechanic claims the turbocharger is totally shot. No billowing smoke or anything indicating a blown turbo, though. Hard to tell because of the cold weather
• Oil is coming from the exhaust from... somewhere
• Shuddering at idle (poor spark?)
• Slightest bit of positive crankcase pressure, enough to make a sound but not enough to force so much air out I can feel it
  I have not been able to test if it remains this way or not beyond a few seconds after a cold start due to the rough idle (could simply be building pressure)
• Brake lights don't work, for some reason (Mechanic identified it to not be a sensor or brake switch issue. Have to check wiring and fuses next)
• Missing front & rear O2 sensors, so it's stuck lean. Needs something for back pressure too, catalytic converter or a muffler maybe?
• A little bit of wet oil is on the sound dampening around the oil fill cap. Holdover from clogged oil trap or worse?

Other noteworthy information:

• Previous repair bill states oil was discovered entering #4 cylinder when the coil was changed
• #4 coil was changed 10k miles ago, now misfiring again
• The car is straight piped, no cats, no muffler, no resonator
• The car has a K&N cold air intake
• Takes a moment longer than usual to start? Even with a (very) cold start my Cruze doesn't take this long to crank to life
• Has a brand new oil trap & pcv system and a new battery to kill those pesky electrical gremlins I had

Some videos of the car running for by-ear diagnostic purposes:

Cold Start - Moved from inside of the car, to left side with air intake, then middle of engine (audio only because it exposed my address oops) - VID_20211127_150237719.mp3
Revving -

The hard part of all this is this: where is the oil from the exhaust coming from? Perhaps the turbocharger? Maybe a failing head gasket? The dreaded piston rings? Something else entirely? I have no idea. Where do I start, exactly?

And a few questions I have:


1. The mechanic I took the car to claims the turbo is shot. Could this cause my spark plug fouling issues and oil in my exhaust? Does it affect cylinder compression?
2. Is there a good way to tell, if there is oil coating the spark plugs, where that oil may be coming from?
3. I've heard that a failing vacuum pump can be a cause for concern in these engines. Is this a possibility I should look into?

Obligatory original thread link: Bought a beater 2013 Volvo S60 T6 R-Design, discovered...

 

[Starrdrop]

Also, here's some bonus images of the undercarriage of the car. First is from the front by the right wheel well. You can see where the oil's leaking from pretty clearly. Second is from the rear of the car. I'm pretty sure that's a little trail of oil on the exhaust pipe? Not sure.

 

[Wayne T5]

At this point I'd have a compression test done on the motor - that should answer some of your questions. Sounds like you have a problem with #4, maybe #'s 2 and 6 as well. If that checks out then I'd dig into the turbo a little more. If it doesn't pass the compression test then you'd either need to consider dumping it or putting in a new motor. You can pull the plugs yourself and see if they are oil-fouled.

The vacuum pump is a trouble spot on these cars and can leak oil so you might want to rule that out while you're looking into the return line for the turbo.

Once you address the motor issues then you need to put a proper exhaust on the car otherwise you'll never pass E-check in Ohio - I think you said you lived in Northeast Ohio. I thought somebody had one for sale here or was offering one.

Good luck with this one - sounds like a lot of issues and you're just getting started.

 

[budleach]

• Turbo is leaking from at least the oil return gasket (I can't find the correct part, if someone could find it let me know!)
  • This is pretty common on these cars. The least of your worries at the moment.
• Mechanic claims the turbocharger is totally shot. No billowing smoke or anything indicating a blown turbo, though. Hard to tell because of the cold weather
  • This is likely (one of) the sources of oil in the cylinders and exhaust. One way to check the wear on the turbo bearings is to remove the inlet pipe and wiggle the compressor shaft to check for end play. Given the mileage and history on the vehicle, I would be surprised if the turbo was not shot.
• Oil is coming from the exhaust from... somewhere
  • Probably getting sucked past the blown turbo seals. The major concern would be, are the cylinder walls and piston rings also worn out? THIS IS THE CRITICAL PIECE TO FIGURE OUT. IF THE CYLINDER WALLS ARE SCORED THE ENGINE IS TRASH AND NOT WORTH DUMPING ANY MORE MONEY INTO. PART IT OUT AND WALK AWAY. You need to do a compression test on each cylinder, and borescope visual inspection of cylinder walls to determine if the engine is worth saving.
• Shuddering at idle (poor spark?)
  • a symptom of all other issues (O2 sensors, turbo, and possibly low compression from damaged cylinder walls)
• Slightest bit of positive crankcase pressure, enough to make a sound but not enough to force so much air out I can feel it
  I have not been able to test if it remains this way or not beyond a few seconds after a cold start due to the rough idle (could simply be building pressure)
  • With a new PCV system. Excess crankcase pressure would indicate piston ring blow by. Meaning the engine is probably worn beyond saving.
• Brake lights don't work, for some reason (Mechanic identified it to not be a sensor or brake switch issue. Have to check wiring and fuses next)
  • OK, maybe THIS is the least of your worries...
• Missing front & rear O2 sensors, so it's stuck lean. Needs something for back pressure too, catalytic converter or a muffler maybe?
  • You can never expect the car to run and idle right without O2 sensors, especially the front O2 sensor. That one is critical. When at any normal idling or cruising load the signal from the front O2 sensor is constantly used to adjust the fuel air mixture. Without that info, I'm surprised the car will even run at all.
• A little bit of wet oil is on the sound dampening around the oil fill cap. Holdover from clogged oil trap or worse?
  • Again indicating excessive crankcase pressure, likely from blow by.

Next step I would recommend is
1. Do a compression test and cylinder wall inspection to determine if engine is worth saving.
2. Assuming compression and cylinder walls are OK (doubtful), get the O2 sensors in the exhaust stream. Even if there is no cat, the rear sensor would just trip an inefficiency code.
3. The O2 sensors should greatly improve your rough idle. If you still have issues ensure you have all new spark plugs, and play musical coils to identify and replace any weak coils.
4. The blown turbo should only really contribute to oil in the exhaust and loss of power. The car should still idle without misfire even if the turbo is seized. If, and only if, everything else up to this step has resolved the rest of the issues, would it be worth investing in a new turbo.

 

[Starrdrop]

At this point I'd have a compression test done on the motor - that should answer some of your questions. Sounds like you have a problem with #4, maybe #'s 2 and 6 as well. If that checks out then I'd dig into the turbo a little more. If it doesn't pass the compression test then you'd either need to consider dumping it or putting in a new motor. You can pull the plugs yourself and see if they are oil-fouled.

The vacuum pump is a trouble spot on these cars and can leak oil so you might want to rule that out while you're looking into the return line for the turbo.

Once you address the motor issues then you need to put a proper exhaust on the car otherwise you'll never pass E-check in Ohio - I think you said you lived in Northeast Ohio. I thought somebody had one for sale here or was offering one.

Good luck with this one - sounds like a lot of issues and you're just getting started.

Ha, if you saw one listed on FB Marketplace that's me! I put it up to seek out buyers in the case I make no progress on diagnostics.
I'm picking up a mechanic's tool kit today to get started. First task is to check the spark plugs for oil. I'm also going to do a visual on the vacuum pump since it's right there, then compression test. If it fails I'm going to call it quits, quoted at $3000 labor just for the engine...

 

[BolboLubber]

Nice to see your still giving this project your best effort.