Will a dirty IAT cause my jeep to vibrate/run kinda of rough at first start up when in park and reverse but not drive it is fine in drive but once it is at operating temp it is fine. I am asking because a few months a ago i was getting oil in the air filter and the intake i fixed that but still am trying to fix the vibration. It starting doing this at the same time and i am beginning to think that the two are related that the oil fouled the IAT senser.

 

since it only does it in park and rev. it doesnt seem to me like it would be an IAT sensor, as it would probably do it all the time... but you could probably try cleaning the sensor with something and see if that helps. What are you idling at? maybe your idle is too low and causing a vibration? could be a idle air control issue maybe? You may want to try to just clean up the whole throttle body. Just open up the throttle valve and spray some carb cleaner in there. If you can use a rag to scrub the carbon and soot out of it. You might be suprised what a little throttle body cleaning can do.

-Brian

 

I don't have a tac but it seems to be right where it always has been before this started I will try to clean those things and see what happens. Where is the idle air control at?

 

In P and N there is no load. So there is a chance that it COULD be the IAT.
Pop it out (unscrew it) and clean with some brake cleaner then Electrical Contact Cleaner.

Cleaning the Throttle body and the IAC cannot hurt.

IAC: Standing on dr.side of XJ, pop air tube off top of TB.
Look inside, on the side furthest from you, you will notice a rectangular-ish port.
The sensor on the outside of that port is the IAC...IIRC

 

thanks i will try that. I forgot to say that it vibrates when i am coming to a stop but when completely stopped it goes away could that be a u-joint that is causing all the vibrations?

 

i would think a u-joint would also give you vibrations at certain highway speeds as well... or on heavy acceleration/deceleration. could be a brake pulsation... can you feel it in the steering wheel or brake pedal?

-Brian

 

I mostly feel it in the steering wheel but really it shakes the whole car when i pop the hood the power steering pump vibrates more than the valve cover if that means anything. I just got my SYE and taking out my t-case drop so maybe that will fix it

 

This might help.