[Dllrd23]

Originally Posted by McSpooney

Hey all.
Trying to think of what else to check on this thing. I might go take it for a cylinder leakdown check. I had to replace my bank 2 head on my 03 3chain motor. After its all back together, car seems fantastic on throttle, but at idle it's a little rough. When i say rough, the idle rpm is rock solid, but the engine shakes just a little and you can feel it in the chassis. The real problem is that it throws a cel for misfire on cylinders 4,6. At first my bank 2 cam deviation was at +7 vs my other bank at -2, so I've spent waaaaay to much time fixing that because i figured that was the cause of the misfire. I'm now at -3.5 bank 2, -2 bank 1. Still misfiring. It's just a slow misfire though... but you can feel the engine is a little shaky at idle. At times you'll see the misfire counter on cylinders 4 and 6 go up to like 8 and eventually clear, then very slowly come back up.

Here's the info on my durametric:
Bank 1 deviation: -2
Bank 2 deviation: -3.5
Rkat bank 1: 2.5
Rkat bank 2: 0.61 (kinda sus)
Rough running cylinders 1-3: -4 to -6
Rough running cylinders 4-6: 4-6
Cam inlet and spec angle seem to follow each other pretty closely for both banks.

Here's what I've done to try and diagnose:
Swapped cam angle sensors left to right - no change
Swapped 02 sensors from left to right - no change
Swapped coil packs from left to right, no change
all new spark plugs and even went back to the old spark plugs-no change
looked all over for intake leaks, nothing. Didn't do an actual smoke test, but I sprayed brake cleaner around and looked for any change in idle or misfire count - no change

I do have to note that I found one of the new spark plugs had what looked like debris melted all over the tip that connects to the coil pack. I cleaned both the plug and coil pack and put them back in and swapped that coil pack around to see if it made any changes. no change. When i found this i got super hopeful that it was it, but no luck.

I'm thinking that next I'll take it to a place that can actually do a smoke test or a cylinder leakdown test. I think bent valve is a possibility, but valves looked great when i put them on and I don't think I did anything to bend a valve?

Any other ideas?

I would definitely do a leak down test. in fact, I would suggest saving the money that a shop charge you and buy a decent leak down tester (I use an OTC about $90 on amazon). as long as you have a compressor that will keep up, it is a valuable tool to have in your box. If you replaced the head this would be a cake walk.