Set the valves to about 0.010 extra clearance and drive for a bit.
If they were tight, you can get carbon buildup on the stems, keeping
them from closing properly. They will go tight again very quickly as
the carbon wears off, and you still don't have them closing properly.
The other thing I would suspect is a bad head gasket. Not a huge
endeavor on a 617, easier than on the 603.
One final possibility is bad spray pattern on #4 and #5, leading to
carboned up rings. Good injectors should clear that up.
Peter
On Feb 16, 2012, at 5:28 PM, glenn brown wrote:
I've posted a query about this previously but didn't obtain much to
look for regarding my '85 300TD rough idle and serious smoking
(white) upon cold startup. After ~ 2 min. warmup, the idle smooths
out and the smoking ceases. Note: the car does not burn any oil,
nor does it lose any coolant and the glow plugs and circuit are all
OK. I took the car to a M-B indy in town and they suggested
possibly low compression, so I had them do a compression check on a
cold engine and they obtained the following compression check numbers:
#1 Cyl. 430 psi
#2 “ 445 “
#3 “ 430 “
#4 “ 320 “
#5 “ 320 “
This shop said the M-B spec for the maximum pressure deviation
between cylinders should be no more than 43.51 psi and they
question either sticking oil rings in #4 & #5 or misadjusted
valves. Since I do my own valve adjustments on both my '84 300D
and my '85 300TD, I'm convinced the last valve adjustment (<1000
mi. ago) is OK and the rough idle and serious smoking issue was
present when my brother owned the car, but it's easy enough to
check the valve clearances which I plan on doing tomorrow. Also
note, for those who may not remember, at the suggestion of possibly
the best M-B mechanic in the Pbgh. area, I replaced the valve stem
seals on the 300TD in summer 2011.
Any suggestions?
G. M. Brown
Brevard, NC
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
