I'm changing my oil tomorrow and was just curious what the usual weight oil is that is in my 1990 XJ. 4.0L I6. I am just guessing 10W-30 and am curious if you guys think it's a good idea for me to bump it to 10W-40 to maybe slow my leaky rear main? Also what are some decent oil filters and spark plugs that aren't too overpriced.

 

I use 5W-30 in my '93 Laredo 4.0L . I've thought about using heavier weight, 10W-30/40 just to quiet down the lifters a bit. I've read several posts here of others doing that, but i'll wait for summer to try it.
I use NGK plugs in mine.. no platinums or splitfires, just plain ol' plugs. Most posts i've seen recommend champions.

Oil filters? I've used Fram for years with no apparent problems (here's where the Fram flamers filter in) pun intended But lately I've used oreilley house brand cause they're cheaper and better quality than Fram. Oreilley has WIX, Fram and house brand filters cut in half so you can see the difference inside.

 

Fram = Orange Can of Death. Use WIX, Mopar, or NAPA Gold.

Use 10W-30 oil. Synthetic not necessary.

I've had a lot of trouble from Champion plugs. I use NGK Platinum.

 

Definitely agree with the filters and the wix/napa gold are cheaper than most filters, Purolator gold is another decent one. Synthetic will cause more leaks. I use rotella 10w-30 and I LOVE it. I do however disagree with the NGKs all my jeeps love Champion. As a general rule of thumb I try to keep domestic plugs in domestic cars and import plugs in import cars, things just seem to run better this way. There have been exceptions but thats what works for me.

 

i use valvoline high milage semi syn with a mobile 1 filter and champion coppers.

 

10w30 and Wix or Napa Gold.

Have you verified that's the RMS leaking and not a drip starting from the back of the valve cover, oil filter adapter housing or oil sender?

 

Wix, Napa Gold (made by wix), Mopar, Mobil 1, or Motorcraft oil filters.

10W-30 is fine

Up to 1999 Uses champion copper plugs
2000-2001 Use NGK copper plugs (due to distributorless ignition)

 

Very good point. I often forget that the xj went distributorless. This would be one of the exceptions I was talking about.

 

Okay yea my brother always tells me that Fram is junk! I'm goin down to O'Reilly's in a little bit to grab everything. I'm eager to see how she runs after a tune up! Reeeaaaaallllyyyyy needed the oil change haha..

 

To bad you couldn't get over to my store.... I hook all my xj guys up with oil changes

 

If you want the truth.... wicked is gonna be the better filter. K&N makes a great one too. Oreillys "house brand" is made by fram....

 

Wix.... not wicked lol

 

Dang that's awesome!!!!

 

My user manual says 5w or 10w-30 when it's above 0*F and 5w-30 when it's below. Also, when you first start it up, being the lifters are hydraulic, they are empty at first. It's normal to have a little tick at start up.

 

Just completed my first oil change (both ever and on the 1999 since I bought it). You may have already started but don't forget to check for the old O-ring! I yanked off the old ACDelco (gag) filter and didn't even realize that the O-ring didn't come with it until I fired up the Jeep, built and lost oil pressure, and my wife informed me of the sudden leak Newbie mistake for sure. I used a lot of paper towel today lol

Regarding filters and plugs, I just jammed in Mobil 1 M1-204 and Mobil 1 5W30 as it's going to get chilly soon. PO said he ran Mobil 1 but I have no idea what's up with the crap filter. For other parts I like OEM unless an aftermarket is a clear upgrade. I've read a few posts explaining why the Champion copper ones are best on a 4.0. It was a bit over my head lol.