valve chatter

crazyfastman · Post by **crazyfastman** » Wed Jun 10, 2009 6:36 pm

Ok guys, I'm stumped on this one. While getting ready for a head gasket replacement, I decided to adjust the valve clearances on my 530i since it was pretty loud.

Like an idiot, I didn't bother to check and record the gaps before I adjusted them. Anyway, I adjusted the valves to a tight .012in cold. I replaced the head gasket and got everything put back together and the valve noise was ridiculous. The engine sounded like it was about to fly apart at 1000rpm. So, I checked the clearances and readjusted everything to a tight .010in. Didn't seem to help much. I checked each valve twice using the method I saw on mye28 of measuring between the cam and the rocker arm at .002in smaller than the set clearance. Then I checked it at the valve stem again. Everything checked out. It still sounds louder than a semi-truck engine at idle. I have no idea what the problem is. I'm just hesitant to adjust down any further than spec.

Any help is appreciated. I suspect that I'm overlooking something simple. That's the way it usually turns out.

Note: the head was rebuilt ~500mi ago so nothing should be really worn. It also has a Schrick cam of unknown duration and lift. Induction is via triple sidedrafts. Let me know if there is any other info needed.

Thanks,
Adam

T.Hanson · Post by **T.Hanson** » Wed Jun 10, 2009 9:52 pm

You know the proper place to insert the feeler gage, how to set the cam lobes, check fit after tight, and the way to make sure each cam is in the right place for adjusting, yes ?

Called overlap: When 1 is on the compression stroke, 6 is exhaust, 5-2, 3-4, 6-1, 2-5, 4-3.

I.e., adjust 1 (first number) by seeing the cam lobes of six (second number) are up. Easier to see the pointy ends of the cam are balanced and centered under the flats of the rocker arms. The feeler gage goes under the spring end of the rocker arm, not between the cam/rocker flat.

If this is confusing yell, or check Google search of old posts.

Mike W. · Post by **Mike W.** » Thu Jun 11, 2009 1:23 pm

Echoing T.Hanson's comments, be careful about exactly where the cam lobes are when you are adjusting the valves. Make sure they are pointed down, not just not lifting the valve, it can be deceptive about how early the cam actually does come into play, I did that once and got a very noisy valve.

1st 5er · Post by **1st 5er** » Sat Jun 13, 2009 5:16 pm

Hey Adam,
You want that I come up and help?

Good luck as you get 'er done.
Make your test drive to Texas and help with the tranny swap.

crazyfastman · Post by **crazyfastman** » Wed Jun 24, 2009 8:35 pm

haha Sherman! That would be a heck of a drive to do some car work!

I figured out what the problem was. The cam timing was off a bit. Apparently the sound was the valves just barely tapping the piston tops. I actually paid a real mechanic to check the whole thing out (first time in a few years that I've actually done so) and they gave it a clean bill of health!
Talk about a feeling of relief! Well, I almost destroyed the most expensive engine I have. At least it all worked out without any damage. Oh, and he said I adjusted the valves just fine

Let's hear it for DSM's!

1st 5er · Post by **1st 5er** » Wed Jun 24, 2009 9:36 pm

Timing! Like you said, something simple...
Glad you got 'er done.
That is truly good news.