Knocking from front of engine bay

[4l4life]

I got a 97 tj sport manual with a freshly rebuilt head. A knocking noise has made itself apparent starting a couple months ago but has gone from partial noise to constant knocking. It’s residual as long as it’s running, it gets faster when I accelerate. I think the noise is closest to the front by the power steering reservoir

 

[TJ Jim]

Got the video but there was no sound?

 

[pagrey]

Sounds quiet to me but I'd check the timing chain. On a 4.0 a loose chain sounds more like a knock then the rattle of a chain. It's easy to check moving the crank and feeling for play.

 

[4l4life]

Sorry here ya go

 

[Davidtj]

Take the belt off run it briefly see you have noise or not. I agree with previous post might be timing chain

 

[pagrey]

I'd pull the belts like @Davidtj said and check everything by hand, noise like that should be obvious in one of the pulleys.

 

[4l4life]

Ok I’ll do that and get back to you guys! Thanks much!!

 

[4l4life]

Ok so update, belts pulled.timing pulley has 0 play. All the other pulleys spin and the power steering pulley has a little resistance and doesn’t come close to making a full rotation once spun

 

[4l4life]

Ok so update, belts pulled.timing pulley has 0 play. All the other pulleys spin and the power steering pulley has a little resistance and doesn’t come close to making a full rotation once spun

 

[kincaid.0678]

Have you checked for exhaust leaks? It’s hard to hear well In the video but I know it can sound like a ticking or tapping sound. You had your head off so the manifold was too. When I replaced my manifold and gasket I had the bolts loosen up and cause a leak. Had to re torque them with some medium thread locker

 

[4l4life]

Have you checked for exhaust leaks? It’s hard to hear well In the video but I know it can sound like a ticking or tapping sound. You had your head off so the manifold was too. When I replaced my manifold and gasket I had the bolts loosen up and cause a leak. Had to re torque them with some medium thread locker

I’ll give that a shot, the wierd thing is it’s just coming from the far front by the power steering housing in the engine. Is that noise from the PS housing normal?

 

[4l4life]

I’ll give that a shot, the wierd thing is it’s just coming from the far front by the power steering housing in the engine. Is that noise from the PS housing normal?

 

[JKP]

Pull the belt and start it up. If it still makes the noise, not the accessory drive.

Won't hurt anything to run it for a min or two.

 

[Austin O.]

Reviving this thread because I have a very similar sound...

Something in the engine bay has been squeaking/squealing on and off for the past few months now. Just a couple days ago this stopped but now a knocking sound (Identical to the one OP shared a video of above) has started. I have to think that these must be related. Knocking does not start immediately when I start the jeep but maybe 20 seconds after starting. I can hear it while idiling, its coming from the top of the engine area (if I crawl under the oilpan/transmission I cant hear it nearly as well). Hard to tell if the sound speeds up when accelerating because it's too hard to hear with the engine making noise.

I have a hunch that it has something to do with the harmonic balancer. When watching it while the tj is idiling, I dont think it's spinning perfectly in a circle, kind of wobbling very slightly I think. I had it off about 2.5 years ago when replacing the timing chain and it looked to be in okay shape but it has been quite a while and many miles since then. Is this a possibility?

Any thoughts as to what it may be and what my next steps are in diagnosing? Thank you!