Crazy M30 valves :(

[Kalevera]

Guys:

After a two day marathon rebuilding my cooling system and brakes, I decided to adjust my valves for the first time to see if I could get rid of the ticking noise that appears to come from Cyl 2's intake.

I'd popped the valve cover before to reseat an ejected banjo bolt, so I am somewhat familiar with that process.

I followed the instructions in my Bentley's and also on Don Gale's page. Car hadn't been started in over a day. Since I don't have a 36mm socket, and because I was going to change the spark plugs anyway, I pulled the old plugs and manipulated the cam by rotating the alternator nut.

Everything was going okay: I set the plugs to .032 - .035 and they went in without much fuss. Followed the 1-5-3-6-2-4 rotation on the valves. However, it was REALLY hard to get all of the eccentrics adjusted so that the .012 would slide in and the .013 wouldn't. I would get it set to spec, tighten it, and then the .013 would slide in easy. After much time (~20 min a cylinder?), I finally got it somewhat right. It seems like the car was set to ~ .011 on all valves previously.

Put everything back together, started the car, and the clicking has gotten *worse*. The idle is smoother - I think one of the old plugs was fouling on and off (now everything's firing), but it now seems like a BUNCH of valves are clicking.

The question then is: what do I do next? Do I set the valves as low as I can get them to see if that will eliminate the noises? Or will adjusting the valves even affect the issue? I know that some noise is normal, but the car sounds like it's chugging along at idle, esp with the hood open.

Any advice would be really appreciated!

Best, Whit

[Robin-535im]

It's been my experience that new eccentrics are a lot easier to fine tune - presumably because they don't have a worn spot right where you're trying to set them. When I got new ones on my 91 535: 1) they were easier to adjust, i.e., more linear in terms of adjustment and response, and 2) they were quieter.

I think they are quieter when they are all adjusted the same... so it may not be that new eccentrics themselves make it quiet, but new eccentrics made it possible to get them all just right, and hence, quiet. Get the bolts and nuts while you're at it.

Some on this board have built a bump starter that speeds up the process quite a bit:
http://www.bimmer.info/forum/showthread.php?postid=49790#poststop

I haven't built one yet but plan to before the next VJ.

HTH

[Kalevera]

Hey Robin - thanks for the advice.

In fact, I had a print out of your earlier post on the valves stuck in my Bentley's while I was doing the job. I decided to try to set them all at ~ .012 per the B's specs. However, I think I could get it set to .010/.012 quite easily, and that might be a good temporary fix until I can get the new eccentrics, bolts, and washers.

I think I'm also going to pull and regap the spark plugs up from the .032-.035 to something more like ~.034-.036.

best, whit

[Jose]

Just remember that, adjusting your valves tighter will also bring your valves closer to the pistons...... The valves on an M30/M20 are supposed to rattle a bit. When having adjusted all valves, it's advisable to re-adjust/check all six cilinders again. It seems like double work, but I'm sure you'll find a couple of valves you'll have to re-adjust. Setting your valves as tight as possible will kill your motor as it loosses all smoothnes achieved with a larger gap between valve and rocker.