I have a 2000 and a 2004 Jeep Grand Cherokee. On the 2004 it is a 4.0L it started burning through oil like you wouldn't believe. I found that it's coming out m exhaust pipe when it's running. It idles kinda rough but when put in gear or if I Rev the engine it sputters and dies. Someone told me that it's the catalytic converter but that doesn't seem right. Has anyone else ever seen this?

 

Hi, Wayne, welcome to the forum.

No, that's not your catalytic converter. Though it's being ruined by the oil, it is not the source of the oil. There is no oil in a cat. The oil is coming from the engine, of course.

Sounds like you have major engine problems. Pull your plugs and I'm sure you'll find they are oil fouled. That's why it's running badly.

The oil could be from a number of things, like possibly your valve stems.

Did this start suddenly? Does your engine make any new noises?

 

Is it actually oil, or just sooty black water?

 

My guess is rings and/or valve seals. What do the plugs look like? If youve got oil out the tailpipe, the plugs are surely fouled. Oil fouled cats will literally cook themselves to death, going nuclear as i like to call it. They turn cherry red and the substrate inside melts, plugging the exhaust. Burning oil can get expensive.

Check the coolant while youre at it, to be sure whats shooting out the back end is just oil. How many miles are on it?

 

My guess is we have another one post wonder.

 

sorry, I had not responded I thought I would get notified when someone commented on my post. Well recently I changed both PCV valves and grommets that seems to have helped it run better while idling but it still can't be put into gear without shutting off. The only sounds so far are normal while idle then it sputters and jumps when you try and put it in gear. I was told to spray seafoam into the intake while raising the rpms to 2500 untl I see white smoke come out the tail pipe,, then tun it off for 15minutes or so.. I haven't tried this yet have any of you guys ever done this? Thank you for your responses also I will check the plugs next.

 

Will it stay running if you give it some throttle while shifting into gear? If it does, I'd suspect idle air controller (iac) is dirty or bad. Does it matter if its reverse or forward?

Try shaking and flexing the wiring harness where it crosses from the fuel injector rail over to the firewall and see if it stalls. If you have bad motor mounts, the wiring can develop problems from the constant flexing. Look at the wiring down to the crank sensor on the drivers top side of the bell housing and the O2 sensor wiring, and make sure it's not damaged or near the exhaust. Also have a good look down where the transmission bell housing bolts up to the engine and make sure it's bolted up tight. It's not very common, but it the bolts back out then things can shift when you put it into gear and cause the crank sensor to move out of alignment.

 

Thanks I'll check those this weekend. If I give it some gas and try to shift gears it still turns off. Forward or reverse.

 

The wires all seem to be ok, plugs looks normal.
I took the throttle body off and sprayed Seafoam into the intake. After cleaning the throttle body and putting it back on I got the jeep to start ran for a couple minutes at 2500rpm and then shut it off for a couple hrs while I had the battery recharged. Came back and sounds like a different engine now, but there is still some miss fire feeling when trying to Rev above 1500rpms. Any ideas?