Oil in airbox, yes this topic again.

[pinaplebob]

1058615

Ok, I've got a 92 xj with the 4.0 ho and it is blowing oil into the airbox. Yes i know that this topic has covered several times but I would like to bring it up again. I've read everything on it here and at various sites and tried just about everything I possibly could have. I've checked all the vacum lines for build up and for collaspe, I've checked the valve at the back of the valve cover, (is that the pcv valve?) My fix right now is just to remove the hose the goes to the air box. I was wondering with that valve is, that a one way valve? Should I be able to blow thru and suck air thru it. I mean normal pcv valves don't work like that. Any input would be very help ful Thanks a lot.


[addsig]

 

[Bullet3600]

1058633

Hey Bob your not alone. My XJ does the same thing I've replaced allvacumm lines, CCV valve harness which cost a small fortune at the dealer, air filters, had the valve cover off and cleaned everything spotless and still no luck. The dealer said by replacing the harness it won't blow oil anymore but guess what? still oil. I took a 1 liter bottle and ran the hose into that and empty it once a week :lol: it sucks but it works right now for me..................Bullet[addsig]

 

[dingus]

1058636

guys - the PCV valve isn't located in the valve cover. the valve is located in the intake manifold. bullet - if you're getting that much oil pushed through, there's probably more problems involved (piston rings or valve seals or something)...

-nate[addsig]

 

[Bullet3600]

1058639

I just did the valves and seals when did the head gasket in January, For the last year i've been getting oil in the airbox and did everything the dealer said to fix it. The engine doesn't smoke and runs like new with only 163,000 miles. the oil is clean along with the coolant. I get about a pint of oil a week in the bottle so for the inconvenience of have to empty it there is not much else I can try..............Bullet[addsig]

 

[dingus]

1058667

...so do you just pour it back in or dispose of it?[addsig]

 

[Bullet3600]

1058670

I get rid of it, I fill a gallon jug and drop it off at the station down the road. I kind of think of it as a continuous oil change :lol: [addsig]

 

[pinaplebob]

1058749

Well, I screwed around with it late last night. I found that I had a little too much oil in it, so i drained it out and set it to the right level. That seemed to fix it for right now. I drove about 100 miles today and also about 45 min of screwing around on a frozen pond and it isn't sucking/blowing oil right now. It seems to me that the problem is very random and does it when it feels like it. I think I'm going to just run the hose off the motor like bullet did. Another thing I've seen is that people will remove the hose and put a little breather filter off of the valve cover instead of the elbow. Anyone ever try this. Its something that I've seen in import catalogs nowadays. [addsig]

 

[dingus]

1058819

i had one of those breathers on my CRX... it worked fine, but it won't (shouldn't) pass inspection... because it vents those harmful vapors into the atmosphere. if your blowby is BAD enough, the vent breather could just spew oil everywhere too, all over your engine.[addsig]

 

[pinaplebob]

1058879

The one benifit to living in the middle of know where in the desolate corn/sudvision fields that there is no inspection just yet. But with the amount of growth it wouldn't surprise me if they started. It's really not that bad for me. I only get spots on my air filter. It's nothing compaired to bullets. But it's enough to make the jeep run like crap. I drove it for like 200 miles with out the hose on it no oil was on the engine. It's really weird. [addsig]

 

[MudDawg]

1059036

The PCV system serves to ventilate the crankcase by using manifold vacuum..In the case of the lnjected motors that use the little skinny tubing, if the engine blow-by rate exceeds the flow rate of the PVC system pressure will build up and find a way out...usually into the airbox...backwards flow..the line to the airbox is to assure filtered air is used to ventilate the motor..

It is entirely possible to have a motor that blows by, but doesn't seem to burn much oil. The top piston ring could be worn along with some wear in the first part of the cylinder..the oil control rings are lower on the piston and are better lubricated, and as such could still be doing their job.

There is a test for this condition... it is called a leak-down test.. it will tell you in percentage how much leakdown each cylinder has...A good Hi-Po engine shop can do the test... or if you have access to a shop with a air compressor that puts out at least 7-8 cfm @ 125psi...you can get a good gage from Tavia tool company..bout 80 bucks.[addsig]

 

[adkchopper]

1059045

I had this problem as well, not too much oil just enough to notice it on filter. I took both lines running out of the valve cover off and shot some foaming engine cleaner in them and blew them out with compressor a few times to clean any crud out. Then I took both front breather elbow and rear elbow (some calll it a PCV, but it is not its a CCV ... just a elbow breather with a smaller hole in one end.) soaked them in cleaner and cleaned good. Then unscrew the part out of the intake where the rear CCV valve line hooks to and clean that real good and ream it out with a piece of wire. If that part or any lines are clogged it will cause oil to blow out of front breather. If any lines or connections have hole or leak in them it will cause oil to blow also. I had th replace the rubber boot that connects rear CCV to its line cause it was dry rotted and cracked, just used 2 pieces of rubber hose to make the correct size for line to fit into CCV. Problem solved!! I have heard this is a common problem, and oil will show up in small amounts if driven alot short distances without time to warm up, or if oil level is a little high.

[addsig]

 

[Bounty__Hunter]

1059123

Check a vacuum line for the PCV system for a plastic connector, looks like a splice in the line but it actually does more. It has a small orifice (hole) in it that restricts vacuum, this usually clogs with carbon and is easily cleaned with a straightend paper clip. This can cause the PCV to run in reverse, spewing oil into the filter box.[addsig]

 

[pinaplebob]

1059211

My hose doesn't have a little splice in it at all. What year is yours Bounty?[addsig]

 

[Bounty__Hunter]

1059283

This was on my '88. Check where the PCV lines and vacuum lines enter the valve cover. If they enter a brass fitting screwed into the valve cover, remove this fitting and clean the orifice in it.[addsig]

 

[adkchopper]

1059312

He has a 92, which does not have a PCV valve, it has a CCV valve. Not the same. they stopped using PCV valves in 1990. Don't believe me try to order a PCV valve for it, you won't find one in any parts catalog or store listed for it. try what I said clean the elbows coming of valve cover, and all lines coming off them, and unscrew plug in intake that rear line of valve cover goes to and clean it out good. They get plugged with crud and thats what blows the oil out the front line into airbox. any cracks or holes in those lines or where they connect should be fixed also or oil will blow out as well. :roll: [addsig]

 

[Bullet3600]

1059348

Actually I have an 88' also that does not have a pcv but a ccv. In all the parts books and catologs there are no pcv's avail for 88's and the dealer told me this as well and sold me a ccv for $40 plus bucks.........Bullet[addsig]

 

[adkchopper]

1059403

the ccv should not have to ever be replaced unless it is missing or broken, all it is is a elbow with a smaller end on one side, just clean it and its as good as new. thats why it was 40.00 noone ever buys them ,, supply and demand.
[addsig]

 

[Bullet3600]

1059489

I had to replace it, the thing was all worn, cracked and broken in a few spots from age. I kept checking the rear line and it was free and clean with no junk in it, BUT!!! I never checked the air valve on the manifold where the line went in, it was so pluged the it had to drill the junk out. Oil blow by is just about eliminated now.[addsig]