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View Full Version : I'm embarassed to say that after so many M30 valve adjustments...



Hector
04-09-2007, 10:16 PM
I will give myself a D for the poor job I did last night. The valve chatter is within earshot about 50 ft away from the car with the hood down. As I always do, I adjusted the clearance between the rocker arm eccentric and the valve tip to 0.3 mm with the engine cold. Prior to the valve adjustment, I checked the clearance, and I could not slide the feeler gauge between any of them. Tonight I will adjust them again.

How tight do you guys get the feeler gauge between rocker arm eccentric and valve tip? That is, does the feeler gauge slide freely between these pieces or is there quite a bit of friction?

Another thing I might add is that a new feeler gauge might be in order as the one I have is pretty much chewed up.

Thanks
Hector

Martin in Bellevue
04-09-2007, 10:26 PM
Ya just want a little drag. Deforming the feeler gauge means it is too tight. I like the exhaust valves at 0.012", and the intake valves at closer to 0.010". Noisy valves are happy valves. If the gap changes, the valve tips may need to be dressed by a machinist to ride properly along the eccentric.

Alexlind123
04-09-2007, 10:37 PM
Too loose is better than too tight.

gale
04-09-2007, 11:21 PM
I just set my son's 535i at 0.012" intake & exhaust a few weeks ago. I did them all at the eccentric/valve stem. The intakes were all within a close .012 so didn't change but one or 2 of them. All but one of his exhausts were all tight, I'd say .010 or less so I set them at .012". Now it ticks like crazy. I'm thinking I'll do it again with him helping this time, & set them at .011"

I put brand new eccentrics & pinch bolts & nuts in my 7 about 18 months ago and it really made it alot easier to slide the feeler gauge thru. Made it much more exact in the feel for having the proper gap & it's much quieter than it was. If I remember correctly, I set it at .011" or maybe .010? I forget. I did try .009" once and it was too tight & idled rough so changed it the next morning to .011". It did seem like it had more power when "up on the cam" at .009" but one would have to put it on a dyno to confirm that.

Ross
04-10-2007, 08:06 AM
If you aren't comfortable with doing it by feel then try the next largest guage, which should not fit. The next smaller will be loose of course.
And as said here already it's better to err on the wide side of the spec. Too tight and it will idle like ****, TOO tight will burn valves.
Most of my many times readjusting has been because the cam wasn't in the proper position to begin with.

TC535i
04-10-2007, 05:30 PM
I just set my son's 535i at 0.012" intake & exhaust a few weeks ago. I did them all at the eccentric/valve stem. The intakes were all within a close .012 so didn't change but one or 2 of them. All but one of his exhausts were all tight, I'd say .010 or less so I set them at .012". Now it ticks like crazy. I'm thinking I'll do it again with him helping this time, & set them at .011"

I put brand new eccentrics & pinch bolts & nuts in my 7 about 18 months ago and it really made it alot easier to slide the feeler gauge thru. Made it much more exact in the feel for having the proper gap & it's much quieter than it was. If I remember correctly, I set it at .011" or maybe .010? I forget. I did try .009" once and it was too tight & idled rough so changed it the next morning to .011". It did seem like it had more power when "up on the cam" at .009" but one would have to put it on a dyno to confirm that.
Wouldn't one have more power with looser valves?

632 Regal
04-10-2007, 05:36 PM
at low RPM, tighter for higher RPM but as mentioned if they dont seat when hot its like a blow torch on exhaust valves.

Wouldn't one have more power with looser valves?

E34N
04-10-2007, 11:50 PM
For the longest time, i thought I was not setting the gap correctly.. realized that I should be using a heavier oil... now the ticking is almost gone (well.. not heard while driving and idle sitting in the car)