Crankcase breather

I presume there is one. If so, where? I have a recently developed oil leak on the drivers cam cover at the same time as the oil dipstick working out of it's tube. I had these symptoms on another car and it turned out to be a blocked breather.

Any ideas?

Thanks

[Beav]

The PCV valve is located under the intake plenum, pointing downwards from the rear bottom. See http://www.svxparts.com/diag/?model=...ategory=050-A2 , item #2. You'll need a crow's foot spanner to loosen/tighten and some nimble fingers to change it. Look in the 'How To' locker for help.

[mohrds]

If you tie a string to the new PCV when installing it, you wont swear every time you drop it tying to start it threading.

Also, be nice tothe next person who will need to change it and put a little anti-seize on the new PCV threads.

Just my recent experience.

Doug

To answer your question, the crankcase breather is connected by hose to that pcv valve. I didn't tighten my pcv all the way so that it could be more easily replaced next time.

[MoreIBNR]

The dipstick popping up is most easily fixed by replacing the o-ring at the top. After a while the ring shrinks and no longer grips well.

[Beav]

Originally posted by MoreIBNR
The dipstick popping up is most easily fixed by replacing the o-ring at the top. After a while the ring shrinks and no longer grips well.

But you'd be missing the problem, excessive case pressure is pushing it up. If the PCV system is dysfunctional (or piston rings, head gaskets, etc.) and the pressure doesn't vent out the dipstick it will push out elsewhere, past cam cover gaskets, crank seals, etc.

[MoreIBNR]

So, how can I tell if it is excessive pressure building or just the dip-stick working itself loose and risind an inch ? This has been happening on my car for a long time (years) and stops when I replace the o-ring.

Originally posted by Beav


But you'd be missing the problem, excessive case pressure is pushing it up. If the PCV system is dysfunctional (or piston rings, head gaskets, etc.) and the pressure doesn't vent out the dipstick it will push out elsewhere, past cam cover gaskets, crank seals, etc.

[Beav]

There used to be (still are, maybe?) case pressure testers to detect clogged systems. Try laying a small piece of tissue paper across the open dipstick tube while the engine is running (keep a hold on it in case it should decide to visit the inside of your engine ). You may have to block the fan wash from disturbing the tissue. With the engine running the tissue should at least stay in place, a slight pull towards the tube being preferable. If the case is pressurized it will be blown off of the tube. I haven't tried this but I think it should be a fair test. I've worked on cars that could give a healthy tug on your hand if you layed it across the oil fill port.

I see it this way - gravity holds the stick down, something would have to push it up. A new o-ring only keeps it in place by friction. If you completely removed the o-ring it may turn out that the stick stays in place, as the pressure could possibly vent without disturbing the stick at all (the o-ring making a good seal for the pressure to push against).

[MoreIBNR]

Thanks, Beav. I will have to try that. I guess trying a vacuum guage or a compression may work also.

Originally posted by Beav
There used to be (still are, maybe?) case pressure testers to detect clogged systems. Try laying a small piece of tissue paper across the open dipstick tube while the engine is running (keep a hold on it in case it should decide to visit the inside of your engine ). You may have to block the fan wash from disturbing the tissue. With the engine running the tissue should at least stay in place, a slight pull towards the tube being preferable. If the case is pressurized it will be blown off of the tube. I haven't tried this but I think it should be a fair test. I've worked on cars that could give a healthy tug on your hand if you layed it across the oil fill port.

I see it this way - gravity holds the stick down, something would have to push it up. A new o-ring only keeps it in place by friction. If you completely removed the o-ring it may turn out that the stick stays in place, as the pressure could possibly vent without disturbing the stick at all (the o-ring making a good seal for the pressure to push against).

[strange179]

While replacing all the vacuum lines and hoses of that nature on one of my SVX engines I have noticed that there are two seperate systems for venting the crankcase. There is on that connects from the PCV to a F connector under the intake pipe in the passanger side of the engine. The bottom of this connector is connected to a fitting near the rear of the crankcase. The other part of this fitting is connected to bottom of the intake tube just after the pleated section.
The second system is the two tubes that connect to the top pf each valve cover and then into a "Y" tube. This Y tube is sorta molded into the bottom of the plastic intake tube right near the throttle body. The other connector of the Y is connected by a short L shaped hose to the main intake tube. This second system has a "valve" assembly on the top of each valve cover. I don't know if this will help you at all but I thought I'd pass along the info.
Jay

P.S. I am currently running on less than 3 hrs sleep so that is today's excuse for any spelling or gramatical errors including punctuation. Any other time it would just be general toopidity.

[Beav]

The system requires not only vacuum but also a supply of clean fresh air in order to be effective. Fresh air is picked up between the air filter and the throttle body, allowed to enter the case at some point(s) and then 'vacuumed' out by the PCV and burned in the cylinders. If the PCV valve becomes severely clogged the case fumes can push backwards into the fresh air portion of the system and leave a mess in the air filter box, etc.

[strange179]

Thanks for the reply Beav. That makes more sense now as to why the hoses are plumed upstream of the throttle body.
Jay