1991Jeep_Man

One of the greatest inventions of man... Marvel Mystery Oil. MMO is like Red Wine for a Jeep Cherokee. Makes a good body wash as well.

Zach2610

I took a guess and figured that was it so i bought it and engine flush. Fingers crossed....

hidetheid

You said smoke? White is fuel so ur injectors could be messed up. Try up grading them there are lots of places selling rebuilt 703 bosch for 60 to 80 a set

1991Jeep_Man

Zach, PLEASE make sure you use the engine flush correctly. I've seen guys buy it and not use it the proper way, wipe out bearings and other odd-ball issues. Poor that stuff into your engine just before you do an oil change, run at IDLE only for I think 5 or 10 minutes, then shut down and drain. Refill with fresh oil (minus a qt), then add the qt of MMO. Or, only add 5 1/2qts of oil, and only use 1/2 qt of MMO.

Good luck man! Hope it works out for ya!

Zach2610

Thanks, would you use a little Lucas too or not?

1991Jeep_Man

Been there, done that with Lucas. My opinion:

Over-rated
Unnecesary
Just thickens the oil beyond comparison
Actually makes oil 'froth' from air bubbles.
Also, I actually had a Puralator PureOne filter go out after putting Lucas in the crankcase...

The MMO will be enough. Try and stay away from "cure all" snake oil additives. Not many of them work. I've had luck with only a few, and MMO is on top of the list.

If you have some slight oil consumption, slightly low oil pressure, and excessive engine noise, consider using a 10w40 or 5w40. When I switch to the Xw40, noise was down, pressure was slightly higher, and I burned less oil. And UOA's (use oil analysis) show good wear numbers with Xw40 oils in an XJ.

Zach2610

Ok cool

Zach2610

Ok well its a little better......

1991Jeep_Man

What do you mean? What oil brand/weight did you go with?

Zach2610

Gtx 10-40 high mileage, its a little smoother but i still get a pretty bad rattle sound when it changes gears at about 45mph. It sounds better idling now though. And i found one of my oil leaks

1991Jeep_Man

Progress. Where's the leak at?

As for the rattle noise, where does it seem to be coming from most? Flex plate bolts coming loose is a very common issue as well, but I'd think you'd hear it at idle too. When you say rattle, does it sound like a metal-metal slapping noise, or what?

Zach2610

I sounds like a clicky ticking rattle like loose or somethin but it only happens accelerating and so i can only tell that it from the front, i back off the gas and it stops but if I continue and let it rattle/tick it will eventually run hot; especially if its under a load like pullin a lawn care trailer. I'm not sure what's wrong, my dads xj he used to have did the same and he had the engine rebuilt. I just can't think its completely wore out because everybody else gets way more miles ya know. I love the jeep but I can't get it to run cool and I don't know if the heat causes the ticking or the tick causes the heat but I have a newish water pump and a nice radiator. The radiator did help but its not gone, I have a stock fan and no shroud cuz it broke. If I get a thermostat other than stock will that help? Or do I need to just give up

1991Jeep_Man

Never give up. No XJ is worth giving up on.

After describing your issues to me, I dont think the rattle/clank noise is associated with the overheating. Do you have a Check Engine Light?

Does the rattle/clank sound similiar to this?


Also, did you test your cooling components with the tricks I told you about? The thermostat would be a good place to start, however going to a lower t-stat rating wont help much. Also, the fan shroud is actually a neccesary item for optimum cooling. Try and find someone parting out an XJ and grab one to replace. Any coolant leaking under the water pump?

I'd start with the t-stat (replace it with a stock unit or a 180*, you're choice), see if that helps. Also, try and grab a fan shroud.

Zach2610

No its much less pronounced. It sounds ok idling (exept for the cloud of white smoke from the muffler) but at about 43-45mpg when it shifts gears I get my sound but its not very loud at all compared to that link. Ill get that fan shroud from the junk yard or quadratec and try a new thermostat next. I would video that sound to show ya but it won't do it idling like that but if I really get on the gas it will do it at any speed, its not like I think I'm gonna break down or nothin but 33" tires are in its future one day and I really need it more mechanicly sound before I start working on the looks

1991Jeep_Man

Is it white like cold start smoke or does it smoke even when hot?