Soooo I recently purchase a replacement 4.2l BHF for my S4. The engine has approximately 77k on it and has good compression. No oil pooling on valves and was pretty clean for being a “recycled” engine.
So I installed it myself used all OEM parts on the install. Upon firing her up the engine start ticking on the top end on the passenger side. Further investigation revealed the tap/knock is RPM dependent and gets quieter when the engine is rev 'd up. I thought is was the intake but I ruled that out and also thought it could be a lifter. So I bought a stethoscope and and listened around. The sound resonates on the passenger side, it’s quite loud in the rear on the head but gets quieter as you gets towards the nose of the car. It’s very pronounced at the rear by the timing cover below the PCV valve and can be heard under the bell housing too.
Now I’m not throwing a CEL or experiencing misfires. I drove it around for 10 minutes and it stayed the same. Power seems to be there and I didn’t find any metal in the oil filter. I’m running 0W-40 with a quart or Marvel mystery oil and planned on switching to 5W-40 but I doubt that will cure the knock.
All the guides were in tack and replaced. My only thought is that it could be coming from a tensioner.
Justin I’m hoping you have an idea what the noise is. You are king when it comes to answering my questions!
Here’s a short video of my sound
Hopefully I’m not experiencing rod knock or a collapsed lifter.