budboy315

Hey everyone,
If i can possibly get some help. my 2000 jeep Cherokee has been leaking oil from the oil filter. i changed the oil filter thinking that the person who changed the oil maybe cross threaded the filter but it is still leaking oil from somewhere. it also has three codes that it is throwing. a p0300 p0301 p0304. these are a multi cylinder misfire and a cylinder one and four misfire. i cannot figure out what is going on with it and cannot afford to get a brain to look into the computer to find out what is wrong. also i checked for air leaks in all the vacuum lines and there are no leaks. if anyone knows how to fix this please let me know. oh also the temp of the engine is sitting below spec. instead of 210 its running at 180-190.

belvedere

The leak is probably the oil filter adapter O-rings.

There are quite a few possible causes for misfires. Gonna have to dig in and get your hands dirty. Has a good tune-up been done lately? Plugs, wires, cap & rotor, clean IAC, run some Techron through the gas, etc.

cruiser54

Here's a write-up with pics.

https://www.cherokeeforum.com/f51/oi...o-ring-127359/

budboy315

Hey I changed the plugs about a month ago and checked all the gaps yesturday and they are good. Also I tried to get the oil filter adapter off and there is very little room to get the screw out of it. Its a t60 bit screw and I cant get any leverage on it. Also there is no cap and roter. Its a coil pack on the newer 4.0l jeeps. However I did take the battery cables off and reset the computer and the codes for the misfire havent come back. Any sugestions on getting the adapter off to change the orings?

Turbo X_J

"Any sugestions on getting the adapter off to change the orings?"
You can't be a girlie man using a 2" ratchet handle, put some torque on it and get it loose.

"the temp of the engine is sitting below spec. instead of 210 its running at 180-190. "
What color is the coolant? the oil?

s346k

I ended up knocking the torx portion out of a socket and using a 12 mm wrench on the hex end of the torx and another wrench on the end of the 12 for leverage. it was no problem.

and it prob has a 180 Tstat in it. might take 5 mins to check.

cruiser54

ask and you shall receive.


http://www.jeepforum.com/forum/f19/o...iteup-1339088/

KungFuGrip

Just wanted to share that I have a 96 Cherokee, and I thought it was my oil filter leaking but it was the oil pressure switch above it leaking down. It will leave a pretty good sized puddle while idling, twist the housing and it stops.

cruiser54

That's why I came up with this:



　
I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.
Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking.
Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?
A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.
First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.
Revised 02-26-2013

KungFuGrip

Haha, yeah man. My other vehicle is an '86 Ford Ranger, and it leaks from the top end, bottom end (RMS), and in between. I only worry about it when it stops leaking.

Fords and Jeeps are notorious for leaking, but they never fail until something awful happens.