Excerpt:
PCV valve Problems:
"Now this system is so simple, what could go wrong?
Well, it turns out, lots of things that cause more problems
than some people realize. What if you take your fancy European
Luxury car to a quick lube place, and the new guy changes
the oil but leaves the dip stick out some. And then the
engine won't start because now there is an extra vacuum
leak through the engine. And he panics because he thinks he
just ruined this $40,000.00 car, and he cries to his boss
that he didn't mean to... And the boss plugs in the dip stick,
and all is right with the world again.
Or what about the old Volvo owner that has had every seal
and gasket on the engine replaced, but the engine still
leaks oil. Until somebody cleans the flame arrester screen
that is part of the PCV system. Now the blowby doesn't get
trapped in the engine and blow out the seals to escape.
Or what about the new Ford brought into the dealer for a
tune-up, but the parts department can't be bothered keeping
those little valves in stock, so they get an after-market
valve and now the customer has a hesitation on acceleration.
And there's lots of complaining about this $300.00 service.
How can this be? Well that valve and spring in the PCV are
both calibrated to give the right amount of vacuum leak for
that engine--a small leak at idle and a bigger leak under
light to medium load when more blowby is created. If you don't
have the exact valve for that engine, the valve can open too
much and be too big a vacuum leak on light acceleration. (Don't
ask me how I know about this one.)
One more. What about the top notch driveability technician
that has a car in his stall that won't idle. He does
every check in the book, but finally, after two hours, pulls
the plastic PCV valve from the valve cover and sees that it
came apart on the inside. There is no valve on the inside
that shuttles back and forth against the spring to create
the right amount of orifice. So there was a huge vacuum leak,
but he couldn't hear it because it was inside the crankcase.
Another problem: the engine ..."
The article contains these sections:
- PCV Valve Problems
- Fuel Evaporative Problems
- Air Injection Problems
- EGR Problems
- CAT Problems
