Help me figure out that noise/ Idle problems

[DETe36]

Ok, so 1997 M3. Recently had some issues with misfiring. Finally figured out it was my check valve not working anymore and was full of condensation and it and my secondary air pump had failed so I replaced them, and finally my check engine lights, idle/ acceleration returned to normal. Just to be safe I replaced the coils and spark plugs(NGK bkr6ek's, the copper two prong ones) and cleaned my MAF/ ICV. Everything is working great finally except...

Actually I had this problem before the others, but I assumed they were related and would go away with the problems and check engine lights, but they didn't. Anyways, it is only idling at about 650 RPM, which seems low slightly rough, like it should be better. Also, there is an intermittent slight clunk noise I also hear on idle that drives me crazy. It's totally random and doesn't even affect engine speed so I can't figure it out, seems to happen approximately every 30 seconds or so, sounds like a mix of a surge and a clunk, although it could be either, I'm not good at describing sounds. Also has no effect on acceleration at all.

I have no aftermarket amps/ headunit/ speakers or anything in the car, and my battery is only 1 year old. It may not even be electrical, but SUGGESTIONS PLEASE. I'm stumped here.

[graywolf316]

You may have damaged the MAF cleaning it. Not certain just a suggestion.

Also double check the coils and spark plugs. Are they gapped correctly?

Maybe also check the throttle body and intake man?

Again just some basic suggestions.

[Junk]

Maybe the O2 sensors are no good anymore? Just because I have heard that moisture is bad for them (why you shouldn't mount them at the bottom) and if it was enough moisture to cause your car to run poorly, maybe it has ruined the sensors.

Also I notice another post where someone thought their engine idled at 500rpms, but it ended up being their factory tacho was off by that much..

[DETe36]

O2 sensors are probably older, not sure if the PO changed them, not looking forward to shelling out $200+ for them if so.

The MAF I confirmed is fine, swapped it out with another known working unit and tired it out and had the same problem. Any way to check the throttly body and intake man without doing a smoke test? I've been working on an at home smoke test but I really don't feel like putting the time into finishing it yet.

I hooked it up to my Carsoft that I finally recieved and the idle is actually about 700 so I guess it's fine. Here's the read outs. Any other ideas/suggestions?

https://lh6.googleusercontent.com/_3VafvgllCGA/TW7YZFunffI/AAAAAAAAAFU/VBv74vTsgg4/s800/livedatapg2.jpg

https://lh5.googleusercontent.com/_3VafvgllCGA/TW7YZX1FT4I/AAAAAAAAAFY/RLeYwj7SWrQ/s800/livedatapg1.jpg
https://lh6.googleusercontent.com/_3VafvgllCGA/TW7YZkxF1DI/AAAAAAAAAFc/2ZiAc8JSBmQ/s800/livedatapg4.jpg
https://lh5.googleusercontent.com/_3VafvgllCGA/TW7YZ1BPdTI/AAAAAAAAAFg/ITtdttLrEOQ/s800/livedatapg3.jpg
https://lh4.googleusercontent.com/_3VafvgllCGA/TW7YaaekhWI/AAAAAAAAAFk/GKpkW7pN3R0/s800/livedatapg5.jpg

[DETe36]

Bump.

It's definitely an intermittent clunk on the idle and the cylinder 5 misfire is occasionally reading but with no rough running issues anymore. Just need help figuring out what is causing it.