How off is this idle?

[chemprof]

This is my first E30, so, how normal is this idle? It has a clicking/tapping sound that I can't figure out. It's not exhaust related, I've had my valves adjusted 100 miles ago, it sounded better after that, but it seems to have gotten louder since then. Worn eccentrics?

any advice on what to check next? Is this a normal sound for a 200k M20?

https://youtu.be/L0Fasj10fHw

[chemprof]

forgot to add that I've changed/checked the fuel injectors, timing belt, ICV, TPS, CTS, crankshaft sensor. Compression seems OK, with one cylinder being low (but within 20%) of the others.

[UgkNW*]

I just put a 885 head on eta block and it sounds something like this. Haha

[UgkNW*]

I've done everything you've said and I don't know what the problem could be. My head has around 100k and the block 170. In starting to think the timing is wrong but then it wouldn't idle so consistent would it? I have 19lbs injectors I think could be the problem also.

[george graves]

Readjust valves - learn to do it yourself. You shouldn't be paying for such a simple procedure on an e30.

[chemprof]

I did adjust the valves myself the first time (never had done it before), but had them done again when I was getting a vac leak tracked down, as I had done a crappy job. I think my technique is better now.

So, I went back in to adjust them and found that one of the rocker arms had moved very slightly to the right, about 7mm.

I know the rocker arm clamps just pull off, and the rocker can slide a bit. If I move it back over, will it stay there? Is there a notch or key that holds it in place?

[ThatOneEuroE30]

Not sure on m20 I haven't pulled my head apart yet but on m30 the rocker shaft has a groove in it that a snap ring goes in to keep rocker from shifting. I don't think m20 has these though. How far out of adjustment was that valve? Could be that the eccentric didn't have enough pressure on it so when cam went to bottom of the lobe it was shifting because there wasn't enough pressure to keep it in place.


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[chemprof]

Nevermind, pulled the clamp, slid the rocker over and put the clamp back into the groove in the shaft.

much smoother!

https://youtu.be/F9ebYBCHHo8

[chemprof]

Yes, the shaft did have groove to hold the clip in place. The valve was way off (around 0.14?), but not sure if that happened before or after it slipped. The eccentric looked a bit worn, but I don't have a lot of basis for comparison.

I'll have to run it for awhile and see if it stays in place.

[digger]

The eccentric was probably tapping on retainer so the clearances would have very much loose thatswhy it sound so bad. Hope it was not run like that for long and not at any sort of rpm. I assume the clip jumped out of the groove in the shafts the clips do wear out from fretting on very high mileage engines so some come off easier than others