89 Renix 4.0 140k on it. Just did an oil change a few days ago (Castrol 10w 30) - ran a can of Restore through it with it. Has been running fine. Did the differential fluid and few other things so it hasn't been run in a few days. Started it up for first time in 2-3 days. Sounded like a rock (or what I thought was a tool I forgot in the engine or something) was run through my crankcase. It was just a random clanking around. Turned it off. Cranked it over again, had a rough idle and a bit of a slap but smoothed out.

Drove to get Chinese food (worth it), about 5 miles. Ran completely fine, better than ever if anything. Sat in parking lot for like 3 minutes. Moved the Jeep around the parking lot and it started slapping really bad, like a top end clicking that went with the acceleration (like a baseball card in a bike wheel) - got into a spot, it was slapping BAD, oil light came on, I shut it off, called for a tow. About 2 minutes later I cranked it over again, and it ran fine just had a slap to it, but not as bad (sounded like mid engine, right under the valve cover if anything). Turned it off. Cranked it over like 2 more times a few minutes later and accelerated and everything - ran completely fine. After 20 minutes the tow said they'd be an hour. I said screw that, drove home. Made it home totally fine, it's still running completely fine.

DID RESTORE DO THIS?!?!? It's the first thing that came to mind since it sat for a few days and it must have caked on and stuck a lifter or something?

Either way, as a friend also suggested, I'm getting this stuff the heck out of the crankcase tomorrow and doing another oil change, and I'll putz around the neighborhood and hope it doesn't come back....

 

I've run Restore in the 4.0 with no ill effects, in fact it calmed down the piston slap quite a bit. But that doesn't mean yours likes it. Change the oil and filter and see if the problem stops.

 

That doesn't sound ok, there are not many good things that make that kind of sound and turn out to be good..
Gonna ask the stupid question: you DID fill it back up to level, right?

 

Well...I just went down and checked it....right under the "add" line. Wtf. I had just done a change a few days ago, up to the end of the fill line. So either I'm losing a quart of oil in a few days (which it doesn't seem like I have any substantial leaks whatsoever) or after driving it a bit it after a change, the line wanders a bit and drains down?


Ugh....

I'm gonna drive it as is today and tomorrow and see if it happens again.... the oil level was just real low. How it was so low is another question, but this was probably what caused this...

It's been firing up no problem and running pretty good though. If it was anything serious there's no way it would have fired back up.

I'll be dropping the pan soon, probably next weekend. I'll see if there's anything majorly wrong, and I'll probably stop a little leakage at the gasket, and will do the RMS as well.

 

I'm betting you had a sticking lifter.

The Restore is fine. What brand oil filter did you use?

I had a 4.0 that did that for 6 months or so and finally quit it when the sludge got cleaned up a bit. 6 months for me isn't many miles though since I have a company vehicle.

Be patient.

There's another thing to try as soon as we verify it's a sticky lifter.

 

I actually didn't swap filters this time. Still have a Wix on there from last change.

I'm real skeptical it wasn't because of low oil, which I have no idea how that happened other than burning it. Haven't been leaking like anything, been keeping my eye on it since I was thinking the oil pan plug was stripped out real bad. I put the same one back in and it actually seated perfectly fine. Seems to drip maybe a drop or 2 throughout the day if anything. So I'm not even worried about that anymore, but ya like I said I've been watching for leaks. Now I'll just have to watch my oil line very carefully.

I'm real skeptical of the restore at this point too, as is my friend who keeps telling me to ditch it asap.

Idk how I feel about my wife driving it, even with me with her, if it starts while she's at an intersection or something.

I'll try to get a video of it if and when it happens again.