[jeepsyco]

So this past week, I've been trying to trace down a single "pop" after I've parked the Jeep after a significant drive (read 45 mins). It happens about 2 mins after parking. Everything sounds normal then POP and thats it. I think I've traced it down to the passenger side engine bay somewhere. But I'm still not sure. Has anyone else experienced this? I cant figure out while it'd be. I put a BL/MML in a few weeks ago and I never heard it. I've done a quick look at the MM bolts and it seems fine.

Its an 05 LJ with 52k miles.

 

[gregert12]

Backfire? Check your spark plugs.

 

[JimmyB]

possibly an over tightened bolt? maybe the heat from running is expanding a bolt. never really heard of it but who knows. check if the exhaust is rubbing the lower control arm bracket on the frame....maybe it's rubbing funny on cool down.

 

[jeepsyco]

Backfire? Check your spark plugs.

I dont think its a back fire, doesnt sound like an explosion, more like metal on metal like JimmyB mentioned with something expanding then cooling.


Thanks for those ideas, I'll try to take a look at them.

Also, I should mention, nothing else seems out of whack, no crazy noises/rattles/shaking while driving. And it doesnt do it on small 5 mins trips. Which makes me think what JimmyB said.

 

[KaiserJeep]

Let the Jeep cool while on ramps or jackstands. Go underneath, loosen all the exhaust hangers and clamps, shake the exhaust, and re-tighten them in the new positions. Now check the entire length of the exhaust and make sure it does not touch anything except the hangers.

Your MML changed the location of the exhaust, and although I think the sound is nothing to worry about, it obviously bothers you, so this will probably fix it.

 

[Squint]

I had to have them heat and bend my exhaust near the front right control arm because it would knock. Check that area. It was right after I got my mml.