Went to change oil on my 1990 XJ this morning and found the plug was stuck. Tried a 12" cresent wrench, vice grips, rapping on it with a mallet, heating it up, and a wrench tied to a rope with me pulling on it from out from under car. Nothing would make it budge. Unless it is threaded backwards I have been pulling/pushing the right way (bolt turning counterclockwise as I am looking at the bolt). Would liquid wrench be worth a shot? Anyone have any ideas or does it need to go somewhere with an impact wrench?

 

Gunnerman, I would shoot it with some liquid Wrench or PB Blaster (PB Blaster seems to work a little better). Then I would find say an 18" breaker bar. That are the longest bar that you can (can also put a piece of pipe over the end of a ratchet and then pull on the pipe to get a longer arm). As long as you are not deforming the oil pan, keep trying to bust it loose.

Much beyond that, the next steps I would recommend doing is going to involve metal shavings and that would be best done with the oil pan off of the car. Not sure how difficult that may be on your car, but cutting the bolt out is the next option. You have exhausted most of the common ones.

The only other thing that I could think of is what is called an impact socket. Essentially it looks like a big handle with a 1/2" drive attachment on the end. Using a big hammer, you put the socket on the end of the tool with the properly sized socket on the end. Place the socket over the bolt. Now, trying to twist the bolt off with one hand, use your other hand with the hammer and strike the end of the impact socket. This will give a jarring motion and also a quick twisting force to the bolt. It may take a few swings.

I guess my next question is what caused the bolt to get to that point. Sounds like to me it got cross threaded the last time it was put in and the person installing the bolt just kept cranking down on it until it was tight. I find it a little bit difficult to see a bolt getting stuck that should be removed about every 3-6 months. Stripped, it happens. Frozen, something else happened.

 

Well I got it out, tied the wrench to rope and had someone pull on it from outside while I hit it with a 5 lb hammer. Finally came loose... the threads and plug was in good condition, so I think either they tightend it down way to much or it got seized somehow. Don't think it had an oil change in a long time. Thanks for the help and post though.

 

Good news!

I was worried you would be saying that you had sheared the welded stub of the pan, maybe someone used heavy duty loctite?

 

NOrri, heating it up would have softened the Loc-tite so you could remove it. Sounds like some PFM happened in this case. All is good, so, smile and move on.