Rough idle.

Ive read all the posts I could on the forum. I have a rough idle but manageable at idle when not in gear. Put it in gear and the idle drops to 500 and is noticeably rough. Has a hard time accelerating and will throw a flashing CEL. Cylinder 1, and 2 misfire. I monitored and also found cylinder 3 to be an issue and misfiring but not triggering a light yet. Swapped new turbo (factory), new plugs, headgaskets, injectors, mass air flow and its still the same. No vac leaks that can be found anywhere as Ive sprayed it down with brake clean multiple times with no idle fluctuation. Compression test was good, engine sounds strong, no knocking, etc. Any ideas?

Have you done a leak down and compression test?

leak down was done, compression fine

Anyone?

How are the vavle clearances?

try both 02 sensors

Replace both Oil Flow Control Solenoids (advance variable control solenoids). If your take an ohm meter they the manufacture spec is 8 ohms. Service manual says they range from 6 to 12 ohms. Mine were 10 ohms.

 

Anyways... ran great after replacing them. Cost were about $150 each... took me 10 minutes per side.

 

When installing them, oil will drip out max 5 drops. On the passenger side it helps to loosen off the upper coolant chamber. Pull the vacum hose immediately in line with the removal pathway of the AVCS.

 

No more stalling when dropping into neutral.

you've already done a lot! another thought is pcv valve.

also the brake cleaner method of finding vac leaks doesn't always work - perhaps try a boost leak test.

If you did head gaskets you should have checked exhaust valve clearances? That would be my bet!

Looking like a motor.....

If comp/leak is good you might consider Intake Manifold Gaskets. Only $22 and a few hours of your time.

 

Instead of buying new OCV try pulling and cleaning them. $300 in parts for an 'unknown' might not be worth it.

Looking like a motor.....

 

Why do you say that?

How are the vavle clearances?

 

Hopefully an issue with values would show up in the comp/leak down.

I tried to clean my OCV in a solvent bath, didn't really help. So I replaced them. Runs better... not perfect, but better.

 

using the break cleaner method, my mechanic buddy started a fire in the engine bay... now the engine is covered in yellow powder.

compression on both d/s cylinders is low after doing it completely cold. 65psi on front, 95 on rear. Trying to figure out if its the head or the engine. The car starts and idles ok as I said, a little rough no lights. as soon as its under a load it goes to hell.

compression on both d/s cylinders is low after doing it completely cold. 65psi on front, 95 on rear. Trying to figure out if its the head or the engine. The car starts and idles ok as I said, a little rough no lights. as soon as its under a load it goes to hell.

 

They can try a leak down test or add a little oil to the cyl and if the comp comes up it's rings.

 

Either way you're pulling that motor. I'd suggest if you pull it for either you look into some fixes to make it more reliable.

compression on both d/s cylinders is low after doing it completely cold. 65psi on front, 95 on rear. Trying to figure out if its the head or the engine. The car starts and idles ok as I said, a little rough no lights. as soon as its under a load it goes to hell.

 

ouch. were you able to get a compression reading on the passenger side for comparison? although 65/95 is already cause for concern

Passenger is at 130 on both, I cant see it being rings. My guess is valves, but I wont pull the engine, just the head.

Passenger is at 130 on both, I cant see it being rings. My guess is valves, but I wont pull the engine, just the head.

 

That's a lofty guess. Rings are the weak link on most turbo'd motors. Eitherway it doesn't change your cost much.

 

The question is, if it's only the head will you bother to resolve the other known issues before you pay for someone to put the motor back in?

 

Personally, when I found out I had bad comp on cyl 2 and 4, I knew I was going full out. The extra $900 to have them change our pistons was nothing compare to paying to pull and fix a motor a second time for something that could be fixed the first time.

 

Make sure when they pull the motor you replace the oil pick up.

No need to pull motor to pull a head. Takes about 3 hours or so. Im not modding the car, I just want it factory and running. I am very easy on my cars, so if its not broken I don't want to fix it. The extra $900 as you say is a lot of money to a lot of people. Im in a tight spot and tight on money and just need a running driving car.

3 hours is speedy! at least you'll know in 3 hours of work whether it's the head (valve clearances), or if the ringlands are damaged (hope not) you'll be able to see that as well.

did a wet test on compression. No change. Checked valve clearance its way the f*** off. I can tell the heads have been off before and Im not sure who did it but I have a feeling they just threw the buckets back into random places without marking them. The intake valves are essentially stuck open.

did a wet test on compression. No change. Checked valve clearance its way the f*** off. I can tell the heads have been off before and Im not sure who did it but I have a feeling they just threw the buckets back into random places without marking them. The intake valves are essentially stuck open.

 

How long have you had the car and how is this possible to just 'show' up if you've just recently had the problem?

I haven't had the car more than 3 weeks and it hasn't been driven. was told it was a headgasket on purchase. I got the car cheap enough and can get the work done cheap enough to warrant buying the car. I have been chasing the misfire since purchase and wont drive it (other than a test drive) until its right.

The OCV was a waste of $300. Rough idle is back. Crap!