Help with #1 exhaust rocker noise

[JSmoove]

So as some of you may know I've been wading through this puzzle of an '86 535i since April. I'm thinking at one point this thing was someone's pride and joy but as it got passed on to subsequent owners, the maintenance became lax and the car runs in a tired state.

Long story short I seem to be having an issue with the #1 rocker arm being noisy. Ive searched and read all the topics on doing the cam side valve adjustment to 0.008". If you follow the links below and watch the video you well see just how loud it is even after adjusted to this spec.

http://www.flickr.com/photos/95551627@N ... otostream/

http://www.flickr.com/photos/95551627@N ... otostream/

Below are some photos that might help diagnose it as well. I've heard of valve stems being dished, but it looks like in addition to this the rocker arm seems to be pushed too far over and is no longer centered on the valve stem.


1.What is the cause of this? Worn rocker arm bushing? I also noticed that the washer between the rocker arm spring and arm is missing.
2. How bad is it to run it like this aside from the noise being annoying (see second video).
3. I've heard of lash caps, but many seem to not suggest them. Can I use one as a band aid for now until I can get the head refurbished? Maybe an over sized eccentric?

Also i guess I should note that I've checked the cam and no significant ware seems to be present ( at least not like what I've seen on this site Anyway).

Thanks for all the help so far. This site has helped a car novice like me fix a bunch of problems on this thing thus far. Hoping it can come through again.


Number 1 exhaust rocker arm with adjuster eccentric removed. by Brobby87, on Flickr


Number 1 exhaust rocker arm with adjuster eccentric removed. by Brobby87, on Flickr

[tn535i]

First the eccentric should not be centered directly over the stem. It is supposed to be offset in order to rotate the valve as it opens each time and produce uniform wear (or is it ware ). I think the valve stem does look a little rough but hard to say without feeling it. It should have a wear pattern that creates a bit of a spiral due to the action described above. If overly rough a lash cap will help. So what does the eccentric look like? They are cheap and should be replaced if they have a flat spot. That also makes it much harder to adjust the valves anyway.

Moving on to the noise. From my experience if the rocker is unusually noisy it might be due to wear on the cam follower pad and you should have a look at that closely. Once it loses it's convex shape and goes flat or even concave the cam will slap the rocker rather than engage the rocker. Keep that wear going long enough and the follower pad wears all the way our to the outer edge and I think they are then destined to break like this one below. I hope yours is not soo bad. It might quiet down for a test if you set the gap a little tight, maybe .008 on the valve side.

While this pic is an M20 the setup is basically the same. See the shape of the cam follower pad here... Not what you want it to look like.

[tn535i]

I meant to add... It seems there has been some discussion about the oil flow to certain rockers due to the design of the spray bar. First I'm sure you've checked the banjo bolts but some suggest removing the bar and making some changes to the hole sizes I think. Don't recall exactly.

On an M20 it's easy to start the engine with the cover removed and check oil flow, not so easy on an M30 with the AFM over top of the valve cover but you could rig it up just to make sure all the points are getting lube.

And one last thing.. what weight oil are you running? 20w-50 will often quiet these motors down a lot if it has something as thin as 5w-30 in there.

[JSmoove]

First off, thanks for the lesson on how these things shouldn't be centered after all. I guess that's good news, but that also means I've yet to find my problem.

I have changed the oil to the Valvoline 20w-50 that everyone here suggests. Initially I think it had something thinner and it did quiet it down quite a bit.

I'm glad you did mention the eccentric because I did replace that and the old one didnt seem to have a flat spot.

If you see in the first linked video, no matter how much I tighten the gap, the noise is still there when I wiggle the rocker back and forth. I seem to be getting a false reading when doing the valve adjustment.

I thought I've read somewhere here that you can replace the front rocker arms without having to yank the head (just did that for a HG job and really dont want to do that again). How does one go about doing that?

[pldlnr]

It's not going to fix your problem, but the correct spec for a cam side adjustment is .009".

[tn535i]

I wonder if you really don't have much wrong at all. I couldn't look at the video the other day but you only compared two rockers what I saw just now. The other looked tighter and was an intake. It could just be were the cam happened to be relative to the rocker?

Try going through them again and be really sure you adjust #1 exhaust with the cam away from the rocker and compare it carefully to other exhaust rockers. Double check your work on the stem side just in case. Also have a look at the cam follower pads like I described above and compare them all. Same for the rocker shaft parts. Also see if when the rocker is loose if it will wiggle on the shaft any different than others. If they all look a like and adjust alike it's hard to think something is wrong.

When it's running you might just be assuming the injectors ticking is your rocker, maybe not.