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Help!!!

Help!!!
T

tireman74

Jeeper
Posts
237
Media
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Location
Celina, Texas
Vehicle(s)
1982 CJ5
4.2L i6 258
T-176
Dana 300
AMC 20 rear and Dana 30 front
Well it seems I bought a jeep with a bad motor. I have an 82 CJ5 with the AMC 258 i6 / 4.2l in it. It had an oil leak so I sent it to a shop I use on occasion and he just called and said that it is building up so much head pressure that it is pushing oil out every open hole it can find. I am not a mechanic but can replace parts but this might be getting a little over my head.
What do you guys recommend doing? Rebuilding it? Buying a rebuilt engine (if so what goes back in it).
This was purchased to be a weekend jeep and something for me to tinker with.
 
Before we get too into the details of the root cause, sounds like we might need more information on the symptoms...

Where is the leak? (front / back/ right / left) Are you sure it's oil? Does it leak sitting? Does it leak idling? Does it only leak at higher RPM? Does the leak rate change with RPM? Does it smoke? If so, what color? Does it use oil? If so, how much?

Not sure about head pressure...but too much crankcase pressure is mostly due to excessive blow-by, usually courtesy of worn rings.

Is your oil cloudy? If it is you have a coolant leak into the crankcase and as the engine warms it will increase the coolant and possibly air pressure in the crankcase as well.

Need more info...
 
I would suggest a free flowing breather cap to the top rear of the valve cover and clean the pcv valve.
 
Rear Seal, dipstick tube are the 2 obvious places of the leak. Leaks a lot when it is running and drips a little with the engine off. Black smoke.
Sorry he told me crankcase pressure and mis-typed and put head.
No the oil is nice and black.
 
Torxhead said:
I would suggest a free flowing breather cap to the top rear of the valve cover and clean the pcv valve.
Click to expand...

I agree with Torxhead - replace those and see if it's cured. Both can get clogged and cause excessive crankcase pressure.
 
When you say "free flowing breather cap " do you mean a new oil fill cap?
 
Yes...
 
tireman74 said:
When you say "free flowing breather cap " do you mean a new oil fill cap?
Click to expand...
No, you have to ports on your valve cover one in the front and one in the back. You need to put a PVC in one and a breather in the other one. It has nothing to do with your oil fill cap.
 
did your wrench do a compression test??:cool:
 
IO,
I ended up just sending it to a shop that specializes in Jeeps and going to let them look at it and see what they recommend. I had planned to send it to them later down the road for some other things but I guess I will change my plans and the timeline of things I was wanting to do with it.
 
The leak at the rear main may actually be a leak from the valve cover gasket. They are known for leaking on that engine, I know first hand, and I replaced the rear main seal before I found out it was the valve cover gasket. You have a lot going on that needs looking at one at a time if possible. I may have missed it but how does it run besides the leaking oil?
 
Runs good, drove 65 all the way to shop Saturday. This problem is out of my comfort level so I just sent it to a jeep specialist and let them tell what the problem is.
 
Hopefully they will do some professional diagnostics and report what they find and the remedy. From what you have learned so far it may be $$$.
Compression test and leak down test would be in order.Go from there chasing leaks. Good luck to you and your project. :D mike
 
May I ask where you took it??
:cool:
 
I guess if you have to take it some place that works as well as you can hope. I honestly don't know anyone that has ever done any serious business with them. I did buy a windshield frame and gasket from them way back when, I love the frame but have no idea what the gasket fit. Can't wait to hear what you have to say about them.:popcorn:
 
I'll keep you posted.
On a different note, do you know of any jeep shows in our area? I want to look at other jeeps to get some ideas.
 
I am going to check out the next meeting of the Lone Star Jeep Club. They meet in Louisville. do a Google search and check them out.

About Us | Lone Star Jeep Club

they do informal gatherings in several locations around Dallas where you could check out the neighbors.
 
Just looked, they meet the 2nd Thursday of each month. I'll make myself a note to go next month.
 
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