I took my 94XJ to a local Jeep hobbyist install/repair shop with some blow-by in which I have, he explained that I need to flush my engine, but googling around suggests that it may be my PCV valve (which is broken, physically) but also when the guy stuck his finger into the filler cap there was a very good amount of sludge, he wants to charge 40$ for an oil change to flush out the contaminants this week and to return next week to flush it again for another 40$, as well as he will replace the PCV, should this be a go? or should I go somewhere else?
So I guess no matter what engine you have it does need a couple flushes. You should put an additive in, drive it a bit then change the oil. Several times.
I am concerned a bit with the PCV thing. If the mechanic doesn't know the difference between a PCV and CCV, well... Run fast...
Jeep engines are really touchy about the PCV and CCV systems working right or they can blow massive amounts of oil into the air filters. Enough I know a few folks that got suckered into new engines only to have the same oil blow that only needed a $5.00 fix...
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Ah, thanks, you just opened the can of worms that I was looking at. My `89 Cherokee 4.0 is blowing a respectable amount of oil into the filter box, as well as around both valve cover grommets and the filler cap. There's a small diameter hard tube that exits the rear third of the valve cover and enters the intake manifold. There's a large-bore hard tube that exits the front third of the valve cover and enters the rear of the filter box. Clearly something isn't venting correctly, but where should I look?
The rear plastic tube is plugged up. A good soak in carb cleaner and a ream with a chunk of insulated wire fixed mine. 12 gauge automotive wire I think it was.
The CCV grommet in the rear has a metered hole that can be cleaned out with a paper clip. If it has been blocked for a long time, sludge will have built up and the grommet might need to be taken out to clean under it or even the cover removed to really clean it out.
The CCV is calibrated to use the air intake hose from the filter. If the grommets are leaking, too much air can get in and the CCV will not suck hard enough so again oil spits into the air filter.
Same for a worn out oil filler cap.
But if the back tube is plugged, it just spits oil out everywhere, fix that first and see if the leaks continue, if they do seal more up.
Here is a link on it with some part numbers for new:
The link below helped me as well, I just gor my ZJ and it took all of 5 minutes to change the CCV, I was told by a mechanic that I needed a new rear main seal, and quoted 6 to 10 hours to fix. As we were changing the CCV I realised it was probably a simple clean up with carb cleaner and a wire as well. But at less than $10 CDN, I put the new one in. You should use a Forked Pry bar and make sure the prongs are long enough to fit around, you may break the plastic lip.
The grommets on my `89 4.0 were shot as is the connector to the filter box so I went looking for them locally. I hit almost every parts house in town before I happened on the friendly guy at the NAPA store. Now, this is why mass retailers like AutoZone aren't always the better place to buy parts (leaving aside the question of quality for now): AutoZone hires pimple-faced kids who are completely lost if it doesn't pop up for them on a computer screen. "I don't even know where the paper catalogues are" is not an infrequent whine (they're right by your left foot, ya twit). I often look up my own parts at the local AZ and tell them what I need.
So the guy at NAPA listens to what I'm describing and says "I know that we can get them, but the soft parts are molded onto the hard tubing and they're called something utterly wrong in the catalogue."
He checked all the likely index entries in the Balkamp catalogue: Valve cover grommets, PCV, CCV, emissions, vapor, nada. He finally found them by paging through the catalogue, knowing what it looked like. The parts fit a range of years for the 4.0 (something like `87 - `92) and there's three of them: "Left Vacuum Assembly", "Right Vacuum Assembly" and the small-bore tube from the rear to the manifold, whose name escapes me. They _are_ _not_ _indexed_ in the current Balkamp catalogue, but for those who will eventually need to replace these parts here's the Balkamp part numbers 715-1365 (rear) 715-1366 (left) 715-1367 (right). Total cost locally for all three parts was US$41.
Thanks again Mike for the advice. I'll be replacing those parts this afternoon.
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