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Help!!! Oil everywhere!!!

553 views 8 replies 2 participants last post by  redbeard 
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#1 ·
Today I was driving in my Jeep, and I looked out the back window to see lots of smoke. Not good. I pulled over to check it out, and heres whats up. First off, its the 4.2L engine. There is a bunch of oil in the air filter canister, and the little PCV valve filter was soaked. When I revved the engine, tons of smoke belched out of the PCV valve. Also, I noticed that there was an unusually large amount of suction on the oil cap. when I tried to take it off, it was tough to get off, and if I held it a little above the valve cover, the suction would pull it down. I'm not sure if that is normal or not. Also, it makes no power, it was straining to even hit 60MPH. It will idle, but under a load it almost feels like its missing, which is possible considering the amount of oil it must be sucking through the carb.

I am thinking that this is something vacuum related. Any ideas?? Please post anything that comes to mind, because I need to get this fixed if I ever want to go home from school again!!!

MattYJ
89YJ 4.2 5"lft 33"Firehawk ATX
Damn you, Firestone!! Now I have drag slicks!!
 
#3 ·
It could be a broken ring , but it doesn't sound like it. The PCV contains a little ball that could be stuck. This can do wierd things to an engine. Excessive pressure is one of them if there is no other outlet. Check this first.


http://home1.gte.net/rythem/davescj7.htm
 
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#4 ·
Matt,
I had this problem with my 4.2 before the rebuild and the current problems I'm having now....
First, put your finger tip over the end of the PCV valve. Is it sucking at your finger tip? If not then it is bad. Replace it. If it is good...you are going to need to get a pressure gauge that screws into your spark plug holes or an aircompressor. U will need to do a compression test. Get a Hanyes manual for a more detailed description. It could be either the valves or the rings. More than likely you've got pressure blow by from bad rings if your 4.2 has high mileage. You could put an oil trap in the vent hose for the crank case, but that wouldn't solve the problem.

The bad news is that you are looking at a head rebuild or an engine rebuild...well you could just go with a ring job, but I'd rebuild the whole thing if you are going to do the rings.

Let me know if you need some more info on the pressure test.
Robert

Robert87yj/wwwthreads_images/icons/tongue.gif
4.2 w/(4.0 head & MPI) (jeep is down need a new head)
Process of a moonguy after beer
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#5 ·
The engine does have high mileage. I did a compression test not too long ago, and all the cylinders were within spec, or very close. I'm really hoping its not rings, or something that will require a rebuild, I will be under it tomorrow, checking things out, so does if there are any other suggestions that anyone has, please let me know. Thanks

MattYJ
89YJ 4.2 5"lft 33"Firehawk ATX
Damn you, Firestone!! Now I have drag slicks!!
 
G
#6 ·
Worn rings should pressurize the crankcase not cause a vacuum at the oil filler cap. Did you run it without the air filter lid? did that make a difference? If nothing else stands out, pull the valve cover and make sure all the valves are opening and closing. Make sure it's not overfilled with oil. The compression test will tell alot. Pay attention to the sparkplugs also.

 
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#7 ·
before you do anything make sure that your PCV valve is free to move. It sounds to me like your PCV valve is stuck open. this is the only way I know of ot have vacuum in the crank case. warn rings would creat pressure not vacuum.

 
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#8 ·
What would the differances be between a valve and a ring. my 4.2 is blowing oil too:\ I've replaced all the pcv system and it slowed down a little. So I'm going to check the cylanders pressure but I've been told that the engine was rebuilt recantly so i Don't know why this would just start one day.

/wwwthreads_images/icons/cool.gifhttp://members.home.net/paul5696/wwwthreads_images/icons/cool.gif
 
#9 ·
To me it sounds like a worn or broken ring.
In one of our 4.0L motors the rings went bad due to an overheating problem and after that the blow by began.
Have you ever had a problem w/ the engine temp?
Just my $.02.

Member TX 4X4 club Arlington Chapter
1946 CJ-2A ---- stock and rebuilt
1987 XJ ---- stock and waiting to be rebuilt
1998 TJ ---- stock Daily Driver
 
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