MonacaYankee

My jeep has been making this noise since it had 130k miles. It now has 166k so I'm not that worried. What is making this sound? You can't hear it outside with the hood up. It only happens when I am stopped and then goes away as soon I as give it gas.

MonacaYankee

Nobody?

Cowboyformhell

honestly.. it sounds liek your driving on gravel because I didnt hear anything maybe point out the time the sound is clear?

MonacaYankee

It's during the first ten seconds. You have to turn the volume up a lot.

1991Jeep_Man

I'd bet loose flex plate bolts.

MonacaYankee

I already took the inspection cover off and tightened the bolts to spec. It still made the noise after, as you can hear in the video.

Solomon7

I hear it. Maybe just the 4.0's clasic piston slap comin' out in it's "old" age?

Slugger

mine makes that same sound when I'm at idle sometimes. only sometimes. some days I hear it some days I dont. But as soon as I give it some gas it goes away. I was going to post a vid eventually and ask, but now you have so maybe someone will figure it out here

MonacaYankee

That's exactly what mine does.

It's not coming from the engine and the noise never gets louder or increases in frequency at higher rpm. It goes away as soon as you press the gas.

sluggy

ok diffrent car but mine makes the same noise and its a worn bush on a engine/gearbox mounting?

Solomon7

Not the engine? Cuz I hear a clicking from inside mine but that' sjus tthe EGR tick. If it' sa click or tick it' s just the EGR. A knock is another story.

It could just be the sound quality of the camera, but with the depth of the knock's tone it sounds like it' s coming from the bay and dampened by firewall and interior parts. Probably below all the top end stuff ya hear from the bay where the exhaust noise takes over underneath.

The rhythm sounds same rate and speed of 1 piston at idle, ya know, the classic lublublublublublub they all devvelop.
May not be slap per se, but to me it really sounds there is something goin' on with one of them near the firewall like #5 or 6.
\bearing, worn cam lobe, something like that maybe, or just more slap.

Wouldn't worry about it. Mine sounds like a helo is following me on the highway cuz of dying carrier bearings in back lol.

Again we all know camera mics suck at "3-D'ing" sounds though sooooo....

maybe try stethoscoping with one ear plugged and a piece of hose all over the firewall and around the block and components?
I hear this in a friend's XJ so I look forward to what you find out.

Like sluggy said, how's your motor mounts and block brackets look? tranny mount too.
Retorque your mount to block bracket bolts if you haven't. 3 on eack side on the block.
They shear off at the worst times (ask me how I know 800 bucks later lol)and like to work loose.

MonacaYankee

It's definately a tick. Why would an egr tick though? I've never been in other cars that make a barely noticeable tick like this.

flyboy141086

i dont think this is a tick. i had my mechanic do some work on the air conditioning and jeep came back making this exact sound, you couldnt hear it under the hood and it would disappear as soon as i started driving.

there are two air conditioning lines that run into the cabin on the passenger side and right before they go thru the fire wall there is a round thing with two plastic lines on bottom and a electrical plug on top coming out of it. (pardon my terminology but i have no idea what it is) anyhow this was bent down and resting on the ac lines and making the ticking sound inside. scared the crap out of me at first. took forever to figure it out, had to use a stethoscope. ive included a pic, hopefully this is all your problem is. look for anything else that could be against those ac lines.

MonacaYankee

Thanks for the reply. I'll definately check that out asap tomorrow. Did the sound seem to come from the center like in my video? If this is the problem, do I just unbend it?

flyboy141086

it seemed exactly like your video. ya i just bent the thing back up. let me know if you get it fixed