Jeep running rough.

[John - JeepsWorld.com]

Ok the Jeep has perfromed really well up until yesterday.
I was driving and suddenly the Jeep starts running really rough and idling like crap, up and down the RPM needle went. I just drove it home but it was a distance.
I found that the air hose going to the MAP sensor was disconnected. So I hooked it back up, and everything was basically smooth again, but now the Jeep just runs rough in general. And its louder than it used to be especcially the front belt pulleys.
I know I shouldnt have driven the Jeep after it spit the air hose out.
What should I do?
I just changed the oil like 500 miles ago, but after yesterday I probably put an equivelant of 2000 miles on it.

On start up its a lot louder than it was, then settles down, but then the engine is rough when driving.
I have 195 K miles on the 4.0 but after yesterday its seems to be at 300k.

All the air hoses are new.

I havent changed the plugs in a while.

Maybe new plugs and an oil change?

How can I quiet down the belt pulleys too?

 

[martin]

John,

I wish you had given us the model year and mileage on you XJ. On the belt making noise I have some suggestions.

* Remove your fan belt and wipe down all the pulleys with a lint free rag, may want to use water or some spray cleaner to get the dirt off the contact surfaces.
* Turn each pulley and see if the bearing is rough, you could have have a water pump bearing going bad, AC clutch, etc.
* Check the harmonic balancer, at 115,000 mine failed and began to walk forward toward the radiator, it can also walk backward into the timing cover.
* You might as well change out the idle pulley by the AC compressor, they run about $10 at any parts store.
* If you want to change the mechanical fan bearing you have to get a new AC mount bracket from the dealer, they run $75
* once you get all the pullies cleaned up consider installing a new fan belt. I found the goodyear brand claims it makes less noise and on my XJ it does. I believe in changing fan belts every 4 years regardless of mileage.

Bonus stuff:
* if you do all this work you might as well change the mechanical fan clutch since you have to remove the fan to inspect the bearing in the bracket or change the water pump.

HTH

Martin

 

[eric91xj]

If i was you i'd try disconnecting your battery and letting the computer reset itself, see if that does anything. After that if it still runs rough i dunno, maybe just a tuneup? low voltage Tps?
As for the loud pulleys if it sounds like a whining, or bad bearing just spray the pulleys once at a time to see which one is bad, the bad bearing will quiet down after its been sprayed
Changing the oil won't really make a difference towards the problems you have now.

Eric

 

[John - JeepsWorld.com]

disconnecting the battery worked.
I dont know why I didnt think of that, I always tell people that too.
Oh well its fine again and thats all that matters.
Thanks men.,