What's up guys? First post. Happy to have a community like this.

Recently bought a 94 XJ with 133k. Was a former state trooper car, in pretty good shape. Only other person on the title. Since I first got it, have replaced the crank shaft sensor, throttle position sensor, and ECM (had some misfire issues - ECM was problem). When I changed the oil/replaced oil filter, the old oil was like tar. Just pure black gunk. Thought since it was state owned vehicle it had been well maintained. Made me wonder if I should go ahead and change any other fluids while I'm at it?

All the fluid levels are good, and like I said, everything runs well. Love the way it feels. I've started to tackle some rust on the undercarriage and plan on coating it before winter.

Any suggestions for preventative maintenance? Or should I let it be?

Just want to keep running for a long time.

Any feedback would be greatly appreciated

 

Open the oil fill cap in the valve cover and shine a light around to see if its black inside there. If so you probably have a clogged CCV. Run frequent oil changes (maybe every 1500 miles or so) with 1 quart of Marvel Mystery Oil until it looks clean inside the valve cover. You don't want to knock too much loose or it will clog the oil pump pickup tube or jam the main bearings, just let it rinse clean

 

Change every fluid you can think of. Also do a tune-up. Check the belt and hoses. Give the driveline a good thorough inspection, pay attention to anything with rubber, as it deteriorates over time. Welcome to the forum.

 

Check the whole suspension and steering replace anything bad.

 

If it's a clogged CCV, should I replace the elbows and grommets and use carb cleaner as well? Would MMO be enough?

 

Yeah I would definitely make sure the CCV system is working properly. One end gets vacuum from the intake manifold, the other gets clean air from the filter box. There's no valve on these.

I would be careful about cleaning it too aggressively or else large chunks of goop can fall off and block up critical passages. You just want to let it dissolve away