Originally Posted by zaxfire69
So far the NGK plugs are doing great! I filled up and I think in will get close to 300 Miles out of this tank. Usually out around 225 miles. The Jeep runs cooler around 190 F unless you stay idling for an extended period. With the old platinum plugs it ran at 210 F mostly all the time. I'll leave them in. See how it does over the winter. Still have to find this oil leak I have and pray it isn't my rear main seal. I'm going to replace valve cover gasket and oil filter adapter and see if that fixes it.
Can't go wrong with NGK.
Ever read 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 canít see your Jeep from where theyíre at, and good old Uncle Bob seem to enjoy telling you itís the rear main seal. Has a catastrophic ring to it, doesnít it?
A simple leak at the back of the valve cover or other source could produce the same symptoms. You donít need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, youíre 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. "***** 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.