4 banger woes

I have a '94 XJ with a 2.5 4banger with 115k miles. Last Friday night it started blowing oil from the dipstick tube. Its not missing or anything like that, and no smoke out the exhaust. Anyone else have this problem ? If so what did you do ? or what is the problem?

Stick said:

I have a '94 XJ with a 2.5 4banger with 115k miles. Last Friday night it started blowing oil from the dipstick tube. Its not missing or anything like that, and no smoke out the exhaust. Anyone else have this problem ? If so what did you do ? or what is the problem?

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Um ganna have to go with ....

no mo rings in a cylinder... yes?

MATT

Run a compression test. If compression is within specs, the problem is a clogged PCV tube.

Modern engines do not vent the crankcase to the atmosphere. They are closed systems. There are two tubes to provide ventilation (and pressure control): the intake tube comes off the air intake somewhere between the air filter and the throttle body (forgive me for not being more specific, but I've never worked on a '94 4-cyl so I don't have specifics), and goes into the front of the valve cover. The suction side probably comes off the rear of the valve cover and goes to the throttle body or intake manifold. It may or may not have a PVC valve in it. The older 4-cyl engines use a real PCV, but the 6-cyl engines (at least the early ones like mine) don't.

If the PCV valve gets clogged, or if it's a small aperature tube like on the 4.0L and that gets clogged, any blowby pressurizes the crankcase. The crankcase fumes are supposed to get sucked into the engine and burned -- if they can't go there, they get out anywhere they can.

Only one bvung on the 94 I have......

The 94 2.5 does not have but one output on the valve cover.....



See the 90deg vacume line that runs to the air intake? check thosse lines for plugs and see if the vavle cover is clogged at that rear output. I think that is what eagle is refering to.

sorry to jack, but...

I've noticed that when I check the oil in the morning (every morning--leaked for a while) I'll get the correct reading on the stick but I also have oil from just above the safe slot up to about halfway up the stick. Not just a little oil--the stick is covered. First thought was head gasket but that's fine. 93 4.0l which doesn't have a PCV I don't believe but sounds like a similar deal to what you guys are talking about. CCV possibly? Sorry to jack your thread but sounds like what Eagle was talking about.

Yeah, the 4.0L uses a "CCV" rather than a "PCV," so it makes sense that they might use the same thing on the newer 4-bangers. My newest 4-cyl is an '88 and that still has a true PCV valve.

Ive seen the problem but on different engine. Since it's not smoking at the tailpipe, and only pushing oil out of the dipstick, you need to understand that the oil pan is getting pressurized in some way and the only escape for the pressure is out the dipstick and it is carrying oil with it. Bottom line--check emission control system, PCV valve--EGR etc.

Thanks, turns out that the vaccum line had broken on the front right of the engine, just below the valve cover. I repaired that and I havent had anymore spillage. Thanks guys !!