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Rear Main Seal

could also try cleaning it up real good and try filling it with jb weld but it probably wouldn't be a permanent fix
but would probably hold for a while I had a hole in my block where a rod went through jb welded the hole lasted about 6 months till new motor was built that stuff works wonders sometimes
 
54cj3b said:
could also try cleaning it up real good and try filling it with jb weld but it probably wouldn't be a permanent fix
but would probably hold for a while I had a hole in my block where a rod went through jb welded the hole lasted about 6 months till new motor was built that stuff works wonders sometimes
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Great stuff i will take it apart some time this week and take a picture of the cracked part and from there i will try what you guys suggested. JB weld will prob be my first try. Could that be the reason it was leaking so bad? or does that crack really not have anything with it leaking?
 
I like that idea. If you need to pull the engine you might as well get something better to put in. Unless it is leaking worse than before, I would look around the valve cover for oil. It may all be coming from above instead of the rear main. Also, I found that the faster I went the more oil would come out of the valve cover. Pressure builds up there in older motors with blow by. Keep it under 60 and see if it makes a difference.

Tommy
 
crack is the likely cause if its leaking oil as bad as you said yes a valve cover can leak but not to a point that it pours out
 
like tommy said if you need to yank it it gives you the option to go with a nice V6 or V8
 
Before I fixed the valve cover, I blew all but 2 quarts out of the engine through it running at 65 miles an hour. If the leak is just down below, you are right, it is likely the rear main and the dink. But if has oil all over the upper end and down the block, I would suspect a different problem. 5w20 oil makes it that much worse. Like I said, if the clutch isn't slipping, it probably isn't the rear main. Just my opinion.

Tommy
 
Tommy said:
Before I fixed the valve cover, I blew all but 2 quarts out of the engine through it running at 65 miles an hour. If the leak is just down below, you are right, it is likely the rear main and the dink. But if has oil all over the upper end and down the block, I would suspect a different problem. 5w20 oil makes it that much worse. Like I said, if the clutch isn't slipping, it probably isn't the rear main. Just my opinion.

Tommy
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I will try to do the valve cover again today or tomorrow and what weight oil should i use? something vary thick im presuming ?
 
I have an '81 CJ5 with a AMC 258 i6 / 4.2l . The book calls for 10w30. I use straight 30. I am sure there other good opinions out there. Before doing all that though, check and see if the oil is leaking around the valve train, exhaust, coil and all down the block. If it is leaking as bad as you say, it will be all over the top end of the motor and down the sides if it's the valve cover. If it's just in the Bell Housing area, 54cj3b is on the money with his diagnosis. Good luck.

Tommy
 
I always run 20/50 in the summer in the older engines seems they run a little cooler :chug:
 
well i finally got to fixing the gaskets again...i redid the valve cover and oil pan...i have videos i will post in case others want to look at them. they arent the best but they will help. I let the RTV harden from yesterday and when i got home today i filled it up with oil...before i even turned the car on it was leaking from the valve cover making me think it might be bent or messed up in some parts. I finally filled it up to the top and cranked the car up...THERE WAS NO LEAK from the oil pan or rear main seal!!! So i at least fixed the harder of the 2 leaks...what should my next step be? get a new valve cover or try again with a new seal and RTV...this past time i got a cork seal and RTV'ed both sides of it and it still somehow managed to leak!!!i have a feeling that it will just leak again if i use a new cork seal and RTV...anyone know of any websites that have new valve covers off the top of ur head?
 
polish85 said:
what should my next step be? get a new valve cover or try again with a new seal and RTV...this past time i got a cork seal and RTV'ed both sides of it and it still somehow managed to leak!!!i have a feeling that it will just leak again if i use a new cork seal and RTV...anyone know of any websites that have new valve covers off the top of ur head?
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The AMC 258 i6 / 4.2l had a plastic valve cover and had a problem with leaks. Not sure about your AMC 232 i6 . When I had a AMC 258 i6 / 4.2l I replaced the valve cover with one made by Clifford. You should check out Quadratec.com or 4wd.com. I'm sure they both have valve covers for your engine. Just don't wast your money on anything plastic.
 
BusaDave9 said:
The AMC 258 i6 / 4.2l had a plastic valve cover and had a problem with leaks. Not sure about your AMC 232 i6 . When I had a AMC 258 i6 / 4.2l I replaced the valve cover with one made by Clifford. You should check out Quadratec.com or 4wd.com. I'm sure they both have valve covers for your engine. Just don't wast your money on anything plastic.
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those covers arent cheap!!!! im going to try to reseal it one more time before i spend 100-200 dollars...im just going to cake on the RTV and pray that it doesnt leak!!! Wish me luck!

i have another question that im sure a lot of ppl have opinions on but...i have the original carb still on this jeep, im looking to beef it up and ive read mixed review on all kinds of carbs. What would make the jeep run the best for the money??? any links will be helpful. i was thinking for the time being i would just buy a rebuild kit for it so i can drive around while im looking and waiting for it to come in.
 
just a thought, but what are you torquing the valve cover bolts down to? If over torqued that will cause leaking as well...
 
kicknjeep said:
just a thought, but what are you torquing the valve cover bolts down to? If over torqued that will cause leaking as well...
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didnt have a torque wrench but i didnt over tighten them...when i took the valve cover off i noticed that the cork gasket moved while i was tightening it down and it wasnt on their correctly...im getting another gasket today and trying without RTV...we shall see if that works...thanks
 
Not to hijack but...

Where are you guys finding decent vale covers for pre-1981 258s? I literally cannot find anything but oem plastic replacements.
 
jerseyben said:
Not to hijack but...

Where are you guys finding decent vale covers for pre-1981 258s? I literally cannot find anything but oem plastic replacements.
Click to expand...
Not sure why the 1980 and earlier valve cover is so much harder to find. Maybe they made changes to the engine or cover in '81.
Here are a couple of options. This first one says it is for 1980 to 1986. Odd that other manufacturers say the early '80s cover won't fit 1980. Talk to someone at Summit before ordering it.
Mopar Performance P4876388 - Mopar Performance Cast Aluminum Jeep Valve Covers - Overview - SummitRacing.com
I'm not sure I want to recommend this 2nd one. It only costs $22.
JEEP AMC 6 CYLINDER VALVE COVER 199 - 258: eBay Motors (item 380257080388 end time Aug-15-10 20:41:38 PDT)
 
I had the same problem with my AMC 258 i6 / 4.2l in my '81 CJ5 . After several tries to seal it with RTV, a friend suggested I try " The Right Stuff " made by Permatex and sold at NAPA stores. I was leery of it at first, just thought it was a gimmick, but it is not silicone based so is not affected by the oil. I put some on the valve cover and the head, let dry for 5 minutes and put it together. Don't over tighten the bolts. I haven't had a leak since and it used to pool drastically after a short drive and the block was covered with oil to. Give it a try before buying a new cover. Mine is the old plastic one and it worked great. First week out I took it over the Rubicon and gave it a work out. Still no leaks. Good luck.

Tommy
 
ill make a sugestion . Iv done alot of valve covers on alot of engines and i found the clean and easy way is to use the grey permatex and lightly glue the seal to the valve cover .SEt it on somthing flat seal down and put weight on it over night . This will stop the gasket from slipping around when you install it .And because i tend to remove mine alot on all my cars (solid lifters) i put a bit of oil o the engine block side of the gasket so it dont stick to the head . The flat surface will also tell you how warped the cover is . Doing it this way iv never had one leak and i reuse the same gasket for over a year ech time . And thats good concidering i remove and reinstall them every other week . Just a suggestion
 
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