98 isuzu trooper buring oil excessively

[Sword King]

Originally Posted by Sword King

My '99 SLX has a PCV valve on the front of the driver's side valve cover. The tube goes to the common chamber immediately behind the throttle body. That is the only vent OUT of the crankcase, and is typical of ALL automobiles I know of for the past 40 years or so. On the other valve cover (passenger side) is the tube allowing filtered air in from the air tube. The PVC valve controls the amount of airflow through the crankcase, and doesn't allow unfiltered air back into it.

Basically your idea would defeat the whole purpose of the PVC system on my '99SLX. What I have decided to do instead is make a 'catch jar' based on the ideas at <http://better-mileage.com/PCV.html> After reading their site, you might consider it yourself.

I bought it with a messed over engine and tranny and have spent the better part of two months getting it running well enough I could get it to a shop and have the codes read. Survey says... I have a 'random mulltiple misfire'. DUH!

Good Luck, SK

Thanks for resurrecting this thread. I had lost it, but wanted to post some results.

I, too, think there are better solutions than replacing pistons. But drilling a finely machined piston ring land isn't a proper solution either, and the time and energy spent doing it would be worth a lot more than just replacing the pistons. However the pistons were not the only changes. Everything I've read says the way to tell the new engine (with redesigned pistons) from the old is the redesigned PCV valve arrangement.

When I took my intake manifold apart, I found the same dirty oil and fuel mixture described above. I cleaned it all out thoroughly, put it back together without a catch can as I described above, got it running, took a 2000 mile trip without major incident other than needing another fuel filter, & using about a pint of oil, but heard what seemed like a leak from the intake manifold gaskets. My son and I took it apart again and discovered the same dirty oily liquid and a leaking fuel injector O-ring (probably my fault from careless reinstallation the first time).

We also made two catch cans, one for either side of the PCV system, and took off on another trip of three thousand miles. Again, we used practically no oil. The catch can on the PCV valve side collected about a quarter cup, the other is still as clean as a whistle. I took the manifold top off again, and NO NASTY LIQUID!

After about 5500 miles, and using about a quart, I changed the oil. It was dark, but not black, and smelled like oil, not gasoline. I was planning on changing oil much sooner, so originally used 15w40 for Diesels, hoping the high detergent oil would clean out any crud, but it stayed so clean I didn't change it right away. Now I'm using Mobil One 5w30, and still don't have any oil loss to speak of.

That's my story and I'm stickin' to it. SK Now I have to change my signature.

[troopertwo]

Hi Sword King! Your advice sounds inspring- I'm burning about a quart every 400 miles which would sound catastrophic if the car didn't seem to run so well and if so many others didn't report the same thing.

You're saying that it seems like the PCV valve is probably sucking oil vapor and droplets from the top of the head and valve cover, then burning it?And just to clarify, you're letting your valve cover simply "breath" by running a tube from it to some sort of container, then filtering "fresh" air heading into your intake manifold with a small rc filter?

If this is so, it would be an amazingly simple fix even for some improvement. Do I have the scenario correct? It sounds logical to me. Please let me know if I'm reading this right if you get a chance. Thanks!