Date: 5-12-08 04:16 From: golf73 in san francisco Subject: after valve job still smoking
had a valve job done and 400 miles later i'm still getting smoke on deceleration on occasion, usually after coming down from freeway speeds.
do the valve seals take time to seat or should this not be happening at all assuming the work was done correctly?
bringing it back to the mechanic this week for head bolt retorq and valve adjustment and am going to have this worked out if there is a problem. _________________ God knows I do the best I can, so fcuk everything
Date: 5-12-08 05:59 From: PatrickMcHugh in Richmond, VA Subject: Re: after valve job still smoking
Misadjusted carbs can cause smoke also! I am having this same problem. _________________ 1976 BMW 2002 Chamonix White
1987 BMW 535is Alpine White
1989 BMW 325is Zinnoberrot --FOR SALE--
1984 BMW 325eta Alpine White --FOR SALE--
1992 BMW 525i Oxford Green --FOR SALE--
1988 BMW 535is Diamantschwarz --SOLD--
Date: 5-12-08 06:25 From: Enrique Subject: Re: after valve job still smoking
If bad valve seals and/or worn valve guides or even valve stems were the true cause of your deceleration smoke - then replacement should have eliminated the problem. If someone was careless in replacing a seal or two so that it is torn from the beginning, the answer is obvious. Valve seals do not need to be broken in, instead they need to be installed with care and not dry.
It may be that you have some other non-valve related problem. Losing brake fluid? If you have a bad check valve that could be one possibility. Another possibility, albeit remote, is excessive blowby created by the new tighter upper end of the engine. If you mechanic is on top of things the issue should be resolvable.
HTH
Date: 5-12-08 06:46 From: Harv in Willoughby Oh. Subject: Re: after valve job still smoking
A seal may have been damaged during assembly. When putting the seals over the valve and valve guide, the seal can get nicked. If you read most repair manuals, they recommend putting cellophane over the valve lock notches to protect the seal when you push the seal over the valve.
I did that once to a teflon seal on my old head.
John _________________ "Chicken make no good house pet!"
"Less brake, more accelerator"
#1665778
Date: 5-12-08 07:45 From: instructorbill Subject: Re: after valve job still smoking
It kind of depends upon what some people consider a valve job.
Are we talking new valves, new guides (reamed to size of course) and stem seals followed by a good grind job and assembly
If as above, it should be good to go.
If you're talking valve lapping and new seals, it kind of depends upon the condition of the remaining parts.
What did you pay, and what did the receipt show for a breakdown of parts, labor, and machine work? What did you agree to have done? _________________ Make it different... or just do it differently
Bill in Petaluma, CA
1969 1600 The current distraction
1970 2002 RIP -- crashed then quartered
1971 2002 M20/02 RIP -- nothing but pieces now
1972 2002 gone, but not missed POS
Date: 5-13-08 06:05 From: TobyB in Seattle Subject: Re: after valve job still smoking
Could also be rings-
how old's your bottom?
heh heh...
t _________________ I have a car disease. There is no cure.
I'm not even managing the symptoms very well...
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