jon1090

last month i was driving jeep and it started making a rumbling oise only while at a stop. but then sometimes the rpm"s drop. . and it'll stall i dont get it im thinking tune up?? also oil pressure guage has been going crazy lately but there is oil and its not overheating so it has to be getting oil correct u'd think this things going to die soon ;(..

MAMMON

What year is it?

jon1090

sorry its a 1993 jeep cherokee laredo 4wd

MAMMON

Well its been happening to a lot of Jeeps. They recalled 500,000 of them a few years back for having defective catalytic converters on them. Here's the link.
http://www.jeepforum.com/forum/f13/9...please-522719/

Im thinking that they never fixed them and now some of us have ended up with the ones that were suppose to be fixed. A bad cat converter will break apart inside and become clogged. When it does that then it will mess up it's idle, make it stall and even just die while you drive it. It will also mess with the power almost like its the transmission and cut into your gas some what.

The dealerships will replace everything else but that and charge you lots of money to do it when I'm thinking its their fault in the first place. Check your cat conveter if its been on there for a while. If you smake it real hard you can hear all the broken pieces shake inside it. That might be why it only happens to it sometimes and other times it runs real good.

jon1090

alright ill check that if it is should i just run it with out the cat.?

Not-Your-Mothers-Jeep

ive had the same prob mine will stumble some time, but i towed a 2080lb trailor plus a WJ. on a 4.0L i just reved it up steady to 3k and let it drop back down and it done good. stopped after that.

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superj

i would verify your oil pressure with a different gauge and make sure your oil pressure isn't really bouncing all over hte place. if it is, and you lose pressure long enough you will mess up your bearings and then have to pull hte engine to over haul.

in reality, you could just have a bad ground wire somewhere but i would be sure since you are getting a rumbling noise to make sure your oil pump isn't going out

jon1090

oh wow i never though of that thanks is there a place in the top or side that i could screw like a piece of **** one that works in ???

trucker

I have bad cat too. Is rumbling and when engine get hot, stumbling when going to full stop. Then pick-up rpm again. Will the loose "shi." inside the cat affect the exhaust (clog)?

MAMMON

I gutted my cat and the thing runs a lot better. I really couldnt believe the horse power and the gas improvement. I think the clogged cat is a huge problem and the other major problem is the the throttle body is dirty as hell. I dont know if its because the cat was clogged and it was sending the wrong message to the PCU and running to rich or whatever, but clean that thing out. I seafoamed mine a couple times and it runs great now. I'm going to go ahead and take the throttle body off and clean it real good but the seafoam made a huge difference right off the bat. You can just spray carb cleaner in there and see if that doesnt help. I did those two things and can now take my Jeep anywhere. Before I was afraid to drive it to the mailbox because I thought I'd be pushing it back. It will sometimes still stall on me but thats when it just first starts up and after I run it for a minute there isnt anymore problems. Thats why I think a good scrubbing on the TB will fix it for good. Its a free fix so it doesnt hurt to try. Even if it doesnt fix it I'm sure it needed it anyways.

jon1090

alrigh i will try thanks a lot ill get back to everyone to see how it went

jon1090

here was what was wrong with it a vaccuum line that goes into the map sensor was unplugged must need vaccuum to work crazy cause it makes the trans all messed up with a rev limiter at 4000 and make it wanna stop running.. also the light comes on! but done fixed now