I have a 1997 Jeep grand cherokee with a 4.0 motor and its had this oil leak. I just found the source and it seems to be coming from underneath where the oil pressure switch screws into the engine block. My concern is that it is actually a crack in the head and the thing it screws into cannot be unscrewed or replaced. I have pictures and really need some insight. Thank you!

 

Please post them if you don't mind? From what it sounds like it is a common problem we get.

 

Are you talking about the oil filter adapter? I know these are a common leak area on the XJ 4.0. I'm assuming the grand cherokee's had them too.

 

Yup! Until 99, they were the same design. There is a simple o-ring (or 2) between the adapter and the block. It's a real PITA to fix because it's mounted with a big Torx-head bolt with limited room to work with.

It could be just the pressure switch, which often gets broken by hitting it with an oil filter wrench. This is such a common problem that when I worked at Valvoline, my store manager kept several in stock in case some clumsy technician broke one!

 

There it is... The OP is under the impression that does not come off.

 

Go to YouTube and search "Jeep oil filter adapter removal" It requires a T60 torx socket cut off for clearance and an o-ring kit.

 

Did this myself not long ago. PITA. What you end up doing is a ratchet wrench , to turn your T60 bit with, and a 1' length of 1" pipe to turn the wrench with as a cheater pipe (I used electrical metallic tubing, called EMT ..home depot) , thin enough to cut to size easily.. You need a sturdy size T60 bit that you then cut down to squeeze in the spot. FYI the reason it is so hard to break loose is they set it at the factory with red locktite. However, it is worth it...leak gone and no more oil smell after climbing a hill.

 

and quite easy to do honestly. I just did mine a few weeks back.

 

Did you find a short torx driver? apparently some are having an issue with clearance. I made thin profile breakers out of flat steel for things like this.

 

Socket to wrench adapter with cheater pipe. I posted about it awhile ago.

 

Knock or cut the bit out of the socket, put a box end wrench over it, interlock an open end wrench with it for more leverage or use a cheaper pipe.

 

I did all of the tricks and mine was seized on. Had to take it to a shop to get it off and they had trouble with it too. Not easy in the least for me.