Some Background:'95 LS 3.0 24V @141k failing inspection due to "obvious smoke" . Time to tackle the 1qt/fill oil usage and valve guide seals would seem to be top of the list. Compression is good BTW and it passed 2 yrs ago with a 1 qt every 3rd fill (1200m) appetite.

I'd like to tap into the collective wisdom regarding 24V SOHC valve guide seals. I've read several posts about the seals on the earlier 12V motors and how they are prone to failure leading to smoke. I've yet to see much on the 24V though, either SOHC or DOHC. A quick cruise of the archive shows conflicting views, although both appear to be dated ('02). Is there a concensus - are the 24V motors just as prone?

Also, are the seals the same on the DOHC 3.5 V6 and SOHC 3.0 24V motors? Not many on-line parts stores even list the 24V 3.0

Thanks in advance

Paul

http://www.4x4wire.com/forums/showf...B69&Number=449861&Forum=,,c20,,&Words=%2Bvalve%20%2Bseals%20%2Bproblem&Searchpage=2&Limit=25&Main=449861&Search=true&where=bodysub&Name=&daterange=1&newerval=3&newertype=y&olderval=&oldertype=&bodyprev=#Post449861

Here's a link to a thread that states it is not an problem with the 24V. I remember hearing that they fixed it with this engine, but I cannot remember when I heard it or who said it. HTH

Carlos

Have you checked/replaced the PCV valve to see if it's the culprit?

Frank

My 3.0L 24V has the smokey symptoms. (I have not done the PCV.)

I questioned the PCV operation, mainly because the hose connecting R and L valve covers (back of motor) was kinked and unlikely to be flowing much. However:
1) PCV valve was definitely operational- checked for vacuum while engine was running and when disconnected the motor stalled.
2)There was some draw on the air inlet on the RH valve cover (not a wholelot though...)as judged by plugging the inlet with the prverbial thumb.

Also,in terms of IDing the guides as the issue, the springs on at least the RHS valve appear to have some slight discoloration/soot on their upper reaches. Ordinarily,I'd expect them to be spotless?

Paul

You say that compression is good... what is it on each cylinder? Sounds like PCV or blow-by issues to me, but let's let some more experienced mechanics than me give you an opinion.

Frank

Compression was an even 190-210 psi with the motor cold. That and the fact all 6 plugs look reasonably tanned made me rule out any "serious" motor issues.
As far as I can tell, its either PCV restrictions or valve guides seals. Either it appears would make the beast smoke after protracted idling.

Paul

Agree - I'd replace the PCV on principle if you don't know when it was done.

You can test it first - start engine and let it get fully warmed up - pinch off the vacuum line between the PCV valve and the vacuum source - rpms should drop about 50 or so. If not, replace the PCV valve.

Frank