Dorkiphus.net

Dorkiphus.net (https://dorkiphus.net/porsche/index.php)
-   Porsche Technical Discussions (https://dorkiphus.net/porsche/forumdisplay.php?f=41)
-   -   PCV? (https://dorkiphus.net/porsche/showthread.php?t=5968)

Spike 05-19-2005 12:49 PM

PCV?
 
I'm still noodling this smoking issue my car has. (I think I may start calling it SB1 for Silver Beauty 1 :wink: )

So, I see smoke after start up and sometimes at STOP
signs and in the braking zone for Turn 1 at SP, etc.

I'm sure valve train clearance is a factor, but it is inconsistent.
Somedays, there is smoke at all. Somedays there is a LOT of smoke.
Mostly after consistently higher and steady revs, like after coming
down the straight at SP at 5800 in 4th, but maybe not so
much when running 4500 in 5th.

If it were seals/guides I'd expect smoke all the time, just more
with more revs and less with less reve, and less as things
heat up and get tighter.

Lucky and I were talking through it, and I think we both are thinking
maybe the engine is sucking in oil vapor from the intake / PCV circuit.

Questions:
- does anyone know the part # for the small reducing diameter rubber
fitting right next to the oil filler on a 3.2? Mine is all cracked and I'm
sure it leaks air if there is negative pressure inside. It is sort
of funnel shaped.

- Is there a PCV valve? Where is it? Or is there a similar circuit
carrying oil vapors and oil mist up to the intake tract?

- Is there a common 3.2 feature I should check to see if it could
be delivering oil to the combustion chambers aside from guide/seal
and ring leakage?

Thanks!

Trak Ratt 05-19-2005 01:32 PM

PVC is possibility but… each time the valve opens and closes it turns slightly in the guide. Keeps the valve face and seat from wearing in patterns that might cause compression leaks and burnt valves. If the guide wears uneven (and they sometimes do) More oil can be drawn down between the guide and valve stem than at others causing erratic smoking. Also, the same pooling of oil in the cam galleries from parking the car can be duplicated in high g turns which can also cause some smoke coming out of sharp corners. Especially where you have abrupt throttle changes. Accelerated valve guide wear is a problem with some Carreras (seems like all Porsches).

:idea: But then again it could just be…. time for a motor drop :!:

matt de maria 05-19-2005 07:21 PM

There is no PCV like the american cars. there is just a constantly bleeding orifice. Try part #7 in pet illustration 104-1 for 1985 911.
Typically high decelerations will suck oil through valve guides/seals.
Typically high accelerations will suck oil from rings into chamber.
If you are sucking a lot of oil vapor through the orifice---blowby. This means P&C on high mileage engine. If the engine is high mileage it looks like rebuild time (valve guides or P&C).


All times are GMT -4. The time now is 03:26 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2026, vBulletin Solutions, Inc.