Neon CAM seal leak.

My 97 Highline SOHC is in the shop for an oil leak.

Diagnosed as CAM seal. Garage tells me that a bad PVC valve can cause pressure
to build up and push this seal out. Is garage giving me the gears?

 

Hi
I have a 96 Neon and have heard of problems in this area before;
sometimes a bad head gasket leak was mixed up with cam seal leak. PVC valve
is not expensive to replace or buy ; I have done this before as general
maintance. Good Luck!

 

Sounds like they want to sell you a PCV valve, not gears.

PCV stands for 'positive crankcase ventilation' -- they are part of a system
that removes potentially explosive fumes from the crankcase and allows them
to be harmlessly burned off in the combustion chamber. As part of this,
they do relieve internal crankcase pressure. They're easily checked and
inexpensive to replace. It would seem to me a plausible explanation for
your troubles, although this is something I've not personally encountered.
For what a PCV valve costs (usually under $20) it's a worthwhile thing to
change as part of regular maintenance. There are also several other
components in the PCV system that need to be cleaned and/or replaced. Make
sure they do the whole job.

--Geoff

 

Yeah, kinda, sorta, but your causes and effects are crossed up. I'm not
sure where you got the notion that the PCV system was in place to avert
hazards created by "potentially explosive fumes in the crankcase". The
purpose of the crankcase ventillation system -- whether it is passive or
positive -- is, at base, to relieve pressure in the crankcase. Ideally,
the PCV system maintains a slight negative pressure in the crankcase. But
no, it is not to "remove potentially explosive fumes".

 

I plead ignorance for good cause: 'twas the official teaching of the engine
rebuilding course I took last fall. Sorry, I don't remember the textbook
name, only that it had a pic of a Viper on the front cover. I won't argue
the point, since I've already said everything I know on the subject, but I'm
quite sure that's where I got it; I was tested on it (got an A, too.)

--Geoff

 

Don't argue with Stern, he knows all, tells all, be in awe.

 

I have seen many times work being done on the timing belt
area/headgasket/or cam and found that the technician never installed the
seal properly, If that isnt the case I would lean more towards the seal is
just hard and worn out, That seal is in there really tight, A PCV valve
being stopped up could not push it out

 

Had more time to think about this. Here:

http://www.autosite.com/garage/encyclop/ency08b.asp
http://home.golden.net/~haida/suzuki/tech/tips/PCV.html
http://www.2carpros.com/topics/pcvvalve.htm
http://www.autoshop101.com/forms/h63.pdf


The last one (the PDF) is particularly interesting. On page 4 it
states: "The valve closes during a backfire to prevent the flame from
traveling into the crankcase where it could ignite the enclosed fuel
vapors."


....and this one at
http://www.carcarecouncil.org/Engine/crankcase_vent.shtml

states:

"Purpose: The purpose of the PCV valve is to regulate the flow of
crankcase fumes into the intake manifold where they can be burned. Prior
to 1963, cars had no PCV and used road draft tubes that just left the
hydrocarbon emissions from the crankcase out into the open air. The PCV
valve also has a secondary role as a check valve, to prevent flow back
into the crankcase. This prevents potential ignition of the crankcase
fumes, should the engine backfire. The PCV system is also crucial for to
proper engine sealing. The system alleviates crankcase pressure, which
can push out on seals and gaskets, contributing to oil leaks."

So perhaps my information was a bit garbled...but prevention of an
explosion in the crankcase is certainly a feature of the PCV system.

To the OP: yes, it would seem that the contention of your mechanic is
quite possibly the cause of the camshaft seal leak.

Thanks for the opportunity to educate myself a bit more thoroughly, Dan.

--Geoff

 

I want to thank everyone who took time to reply. It looks like the mechanic at
the garage is kinda, sorta correct. BTW he was re-iterating what another
mechanic had already suggested. The other mechanic works on Chrysler products.
He is also the mechanic where I usually get my work done.

I'm also glad to provide fodder for the group.

Sorry about my typo (PVC instead of PCV).

syl