Topic: Oil cap leak

[sharpxmen]

This one keeps bugging me.  Part of the reason is if the engine is right (No Bad rings or Cat) you could leave the cap off and not get that much oil.

does the tbi have a check valve on the pcv fitting? otherwise i would think that all the blowby would go in the airbox though, so i'm kind of leaning back towards a bad seating of the cap on the valve cover, speculating of course.

[grumpygy]

does the tbi have a check valve on the pcv fitting? otherwise i would think that all the blowby would go in the airbox though, so i'm kind of leaning back towards a bad seating of the cap on the valve cover, speculating of course.

Looks like a Check Valve type on the PCV valve.  But it has two lines that go from the valve cover.  Look at the 1st photo Front is the PCV valve what is it in the back.

[chardrc]

on the tbi the pcv valve itself is the normal check valve type with the spring and slug, that goes to vacuum (intake manifold). the otehr connection (back of valve cover) that goes to the air-box has a series of filters in that big black canister. those filters can get extremely dirty and would prevent the oil from getting to the air-box (and air from air box to valve cover). so if those filters have never been cleaned or replaced they could be preventing the oil from going into the airbox.
my experience with that canister http://4bangerjp.com/forums/index.php/topic,8503.0.html

[quicksand]

I know this topic is older but maybe I can get some help/answers, I have a 97 2.5L and found just a little bit of oil build up or collection in the throttle body and cleaned it out, also my air filter has just a little oil build up. Not a whole lot but enough to wonder why. But I thought a 97 4 banger does not have a PCV valve on top of the valve cover. Yet there is a hose from the air tube to the valve cover with a thinga magige there that is elbow shape. What is that? Could that be clogged. Or is there a different valve somewhere that could be causing this slight oil build up.? Can someone help me with this. Thanks

[sharpxmen]

there's another sized fitting on the valve cover with a line going straight to the intake, both fittings (at valve cover and intake) and the line are prone to getting buildup, clean them well and make sure they breathe well (put a hose on and blow thru to make sure it is flowing freely after cleaning them).

with the engine at idle you should feel vacuum at the plastic elbow thingy you mentioned (even with the throttle partly open at 3000rpm for example you should still have vacuum and not get blowby gasses out of that elbow).

[quicksand]

Ok sounds good, but to repeat and make sure I understand there is a another hose that runs from the valve cover to the intake which can build up oil and needs cleaning. Is this normal? And if that that elbow thinga migege on top of valve cover is not sucking in air at idle sould I change it ? Thanks

[sharpxmen]

Ok sounds good, but to repeat and make sure I understand there is a another hose that runs from the valve cover to the intake which can build up oil and needs cleaning. Is this normal? And if that that elbow thinga migege on top of valve cover is not sucking in air at idle sould I change it ? Thanks

negative to changing the elbow, it's just a plastic piece with a big hole and nothing in it. the "air sucking" is a result of the air being sucked into the intake thru the other fitting (being behind the t/b you have vacuum at that line).

the other fitting is located towards the front of the valve cover (close to the thermostat), and yes to the questions related to that in your post above (it gets buildup and it is normal)

[quicksand]

Wow love this forum, thanks alot I will start cleaning the hoses, O do I need to remove any fittings in the valve cover to clean or replace? and another question is do I just clean the vacuum hoses or replace them. Thanks for your experience/ knowledge.

[sharpxmen]

i ran some brake kleen thru mine but had to cut one end shorter (EDIT: i'm referring to the plastic line here). the fitting you can remove if it's plugged badly or just run a thin steel rod or small screwdriver thru it to break the carbon, might as well remove it so you don't push all that junk back into the valve cover.

[quicksand]

Sounds like a plan. I will try to get to it this week sometime. Many Thanks and Happy Wheeeling.