engine rattle
JK Junkie
Joined: May 2009
Posts: 3,074
Likes: 1
From: Denton, TX
The automatics are notorious for wanting to shift prematurely. That puts too much of a load on the engine. I can only imagine what that would be like with bigger tires and no regearing. I had to have my engine replaced at 18K. When I got it back, the whole Jeep was a different vehicle. The transmission shifts like it's supposed to and holds the gear out as long as I have my foot in it. Come to find out, I didn't have the latest PCM reflash, and when they reprogrammed it from the engine swap, I got the latest one. The difference was literally night and day. I am actually HAPPY with my Jeep again. I would suggest maybe you go to your dealer and see if it has that latest reflash. It may not. If it does not, AND you have bigger tires without regearing, then that could be your whole problem. The trans is shifting into ahigher gear before it should and causing too much load on the engine making it detonate....at least that's what it sounds like you're describing.
I'm curious as to why the others who complain of this "rattle" haven't tried higher octane fuel. If they've never heard what "pinging" sounds like...it could very well be mistaken for something else in my opinion.
JK Newbie
Joined: Jul 2009
Posts: 2
Likes: 0
From: Greensboro, NC
Check the air conditioner tubes where they enter the firewall going into the interior of the jeep from the engine compartment. That might not be it but I have two friends with 4 door JKs and that was where the noise they were having was coming from. If you have someone wiggle the pipes while you are in your Jeep the noise is reproduced. They both took there Jeeps to the dealer and the problem was fixed. I have a 2 door, my pipes are tight and do not move when wiggled, so I do not have the noise. Seems that it might be a 4 door only problem. Good luck!!