I have a '96 GC 4.0 with 170k and it looks like the seal is starting to leak. I was wondering if there was a good web site to go to for instructions on replacing this before it's to late. Thanks in advance..
Before you go getting too dirty, the 4.0 is notorious for valve cover leaks that run down the back center of the engine so it looks like the rear main is leaking.
To test this, run the engine for a bit, then take a clean rag and rub it around the back side of the engine head just below the valve cover. If you find oil, then you should fix the cover leak first to see if that is all it is.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06Jeep 6 cyl engines are nortorious for leaking out the rear of the valve cover, mimics a rear main seal leak very nicely. Take it to the self service car wash, wash off the back of the engine, the firewall, and as far down onto the bell housing as you can. Wipe it dry, look for any signs of fresh oil. Stick a paper towel between the firewall and engine, below the level of the valve cover and drive it home. If the valve cover is leaking, it will show up within 5 or 10 miles.
Chang> I have a ?96 GC 4.0 with 170k and it looks like the seal is starting to
I traded mine in for a new one after my friends wouldn't let me park in their driveway anymore. :-)
RoyJ wrote:
I have done several without removing the crank. It is a 2 piece seal that slips into place easily if you follow the lube directions on the package.
My current engine had the rear main done in 2000 by me and is still leak free. Now I did have the engine on the ground for this one, but only removed the oil pan and back journal.
My valve cover however has started to seep again.... It is only held by
2 center nuts up top, no perimeter bolts on this old one.Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06RoyJ wrote:
In addition to the good advice others posted, you might want to eyeball your air filter element for signs of oil. If your engine is blowing oil onto the air filter your CCV system is plugged and that will make your valve cover leak. Been there, done that...
The CCV tubing and grommet aren't really serviceable, you buy the whole harness and simply swap it.
See:
-- "We began to realize, as we plowed on with the destruction of New Jersey, that the extent of our American lunatic fringe had been underestimated." Orson Wells on the reaction to the _War Of The Worlds_ broadcast.
I use carb cleaner spray and soak my CCV tube with it, then ream it with a chunk of wire. A paper clip will work to ream the grommet's hole.
It works for me. Mine blocks every couple years with 315K km on her.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: N> >Edward R. Wojciechowski JR proclaimed:
Before you do this, check along the back of the block. The most common cause of this leak is the valve cover, the oil runs down the back of the block and looks pretty much exactly like a rear seal. The seals DO go bad, but more often it is the cover.
Google for Jeep 4.0 rear main seal replace and pick the site with the best pictures.
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