Oh man thats terrible. sorry to hear that
Yeah, not easy to justify after spending almost $8k on an engine.
Bit of an update to anyone following this thread: New turbo was installed. I picked up the car today. No more wastegate actuator code being thrown now, so that’s solved.
So far did two cold start tests where the car sat for over 2-3 hours in 30F weather, and cylinder 4 is misfiring more now after the new turbo.
First cold start had 35 misfires in cylinder 4. Second had 21 in cylinder 4. Most yet since I’ve gotten this engine. No CEL’s or codes have been thrown for misfires just yet which is good (except when my wastegate actuator failed and threw my car into limp mode).
I’m just about to give up trying to figure out what’s causing the misfires in cylinder 4 on cold starts. Maybe it’s normal to have a few that don’t cause a CEL.
To recap what’s been done:
- Replaced all coil packs
- Audi applied “software update” to fix cold start misfires (didn’t fix it)
- Replaced all injectors
- Bought like-new used engine (10k miles on it) once borescope revealed damage in cylinders that were misfiring
- replaced all spark plugs (part of 40k mile Audi Care service)
- installed new turbo due to faulty wastegate actuator
Still no fix for the cylinder 4 cold start misfires. Don’t know what to do next without blindly throwing more money and parts at it.
Could it be the intake manifold since it’s one of the only things that hasn’t been replaced yet?