A Not So Easy Oil Change?

[Dibbons]

Is nothing at all just simple, cut & dry these days? Rather than change the oil at the regular quickie shop I frequent (where they always over-tighten the oil filters) I purchased some motor oil at Sam's Club (store brand) for one of our two Jeep Cherokee XJ's.

Brought a breaker bar and a variety of sockets (did not want to fight with a real tight drain plug) and crawled under the vehicle along with a drain pan. At first I found a 9/16" socket too small and a 5/8" socket too bit. Finally, I was able to force fit the 9/16" on (found out later the head of the drain plug bolt was covered in silicone which caused the confusion).

Well, I didn't need the breaker bar after all, although I used it. The drain plug seemed not tight at all. Was almost thankful for that discovery until I spun the plug over and over again and it made no progress in coming out (found out the threads on the plug are almost completely smooth/stripped).

Now had to put on my thinking cap on how to remove the stubborn drain plug. Gathered up a pair of flat bladed screwdrivers and a pair of vice grips. I then proceeded to pull and twist at the same time with the vice grips while simultaneously prying under the head of the drain plug with one of the screwdrivers. Finally, it started out and I grabbed it before it fell into the pan. I'm going to call it a day now and just tell my story to whoever will listen.

 

[Sixpactogo]

I believe you will be dropping the oil pan. At least you got the plug and oil out. I had that happen on my daughter's Grand Cherokee a couple years ago. The nut inside the oil pan was sweat welded at the factory but came loose. I was not able to get the plug out so drilled a hole through the plug to drain most of the oil then dropped the pan to reweld the nut inside. I assumed it was a fluke but maybe more prevalent on the Jeeps than I thought.

 

[Triplegreen500]

You should be able to get a replacement drain plug, either from Mopar or at an auto parts store. Get one with a magnet on it (you'll see why).

I'm willing to bet the pan threads are fine; worst case you may need to run a tap through them before installing the new drain plug. Get a magnet-on-a-stick to get as much of the shavings out as you can before plugging/filling - and this is why you get a plug with a magnet on it. Worst case, drill it out (put grease on the drill bit to catch metal shavings), tap it out (again, grease on the tap to catch metal shavings), and install a helicoil insert to match the new drain plug.

The 4.0 is a tank, you should be just fine. I ran one for nearly 150k miles after having to replace a holed piston (contractor truck, bought it like that, thought the dead miss on #1 was ignition....nope, it was the holed piston from a bad injector and excessive detonation). Put in a used piston (didn't measure it) with new rings (also didn't measure, just put standard rings on it and ball-honed the bore). I put new rod bearings (again, just slapped some STD's in) and main bearings (yep, you guessed it - no measuring, just STDs). Had about a half second of BRAAAP every cold start, but soon as the oil pressure built...smooth and silent, no oil consumption, ran like a champ. For 150k and a little over 11 years - until the floors and brake lines rusted out, and a buddy bought it to build a trail rig out of it. He picked it up at a hair over 435k miles and it was still running like a champ.

 

[71Beeper]

You should be able to find oversized drain plugs that will self tap into the pan.
Like Triplegreen said find one with a magnet on it.

 

[68-500]

Exactly why you should never allow quick lube places to touch your vehicle.Their moto: The cheapest labor money can buy.

 

[BB BELLA]

the oversized plug may be metric sized plug head like your OE.

 

[toolmanmike]

Metric.

 

[Dibbons]

The 4.0 is a tank, you should be just fine. I ran one for nearly 150k miles after having to replace a holed piston

I had a Grand Cherokee once that just quit running one day. I found one piston had a hole burned right through the top of it. Never understood what could have caused that.

 

[#41]

These quick lube places hire the least of the least qualified and least experienced. You pay for their training.... one way or another..... or even both ways.

 

[Triplegreen500]

I had a Grand Cherokee once that just quit running one day. I found one piston had a hole burned right through the top of it. Never understood what could have caused that.

Probably the same thing that killed my old XJ - a weak injector. A partial shot of fuel doesn't wait until the plug fires; it's "lean" and will detonate. Detonation as the piston comes up, is the rattle you hear...and it equates to smacking the top of the piston with a sledgehammer, every time. Eventually...you get a donut instead of a piston.