Timing chain or rod bearings?

[clunk]

So ever since I bought my Jeep around 10k miles ago it has had what I thought was a stuck lifter. I just finished a 600 mile highway trip across the province and finally pinpointed the noise to the front of the engine, possibly from the timing chain area. The noise sounds like a can full of marbles being shaken at a couple thousand RPM. Basically, I'm pretty sure it's the timing chain slapping around in there. Is it possible the noise I'm hearing could be worn rod bearings or a weak wrist pin? From underneath, I can pinpoint the noise to the front of the oil pan with my mechanics stethescope.

Despite the horrible noise, the jeep still pulled 70 miles per hour up and over a half dozen 5000' mountain passes and blew the doors off a few rice burners along the way while barely breaking 1900rpm. Gotta love the I6!

 

[outlander]

I have the exact same noise on my rebuilt motor that only has about
10k miles on it....been driving me nuts!

I broke out the stethoscope and pinpointed the noise to the timing chain area.Just to make sure it wasn't an accessory bearing or belt noise I took the belt off and ran it,noise was still there.

I felt pretty confident it was timing chain/sprockets so I went ahead and tore the cover off and installed a brand new timing set even though the set that was in there had less than 10k on it.It was a remanufactured long block so I didn't rebuild it myself,I figured that the place I bought it from used a bad /old timing set.

Noise STILL there after new timing set,chain guide and crank dampener!!!
I started a thread on it here a while back and didn't get any definative answeres.....
If you find out the problem clue me in.

 

[outlander]

What year is it?Mines an 89.
One way to tell if you have a worn out chain is to take the dist cap off and turn the crank pulley....there shouldn't be any hesitation.The dist. rotor should move at the same time that the crank is being turned.

 

[Shorty]

had the same issue since I bought this turd. I was figuring it was the chain, but it runs well enough that 'til I have a problem it can rattle it's fool head off and I'll turn up the radio.

Outlander-- did you notice if yours had the oil slinger still attached in front of the crank gear? I've seen people leave that out and get a horrible noise as the chain and gear try walking foreward and backward on the crank snout. How about the spring and "botton" in the face of the cam-- maybe the cam is trying to walk foreward and binding the chain??

 

[outlander]

yep I made sure the slinger was there and the spring and button.
I'm lost.This is a new engine with around 10k since the rebuild.......sucks!!!I was expecting a nice no noise motor after the rebuild.

Come to think of it the old motor made the same noise with about 177k on it....Still I think these motors shouldn't sound like this.

Well atleast I'm not the only one.

 

[doodahman]

If it's an automatic, check the torque converter nuts in the transmission. They sound like a rod knock when they are loose.

 

[99XJWhitey]

just a thought....

I just rebuilt mine, and even though I never saw the harmonic balancer physically wobbling, it apparently was moving just enough to barely touch the timing chain cover and it cause a little bit of a rattle. I wouldnt have known it until I scraped the sludge off of the cover and saw the circular dent in it.

 

[outlander]

5speed.
The balancer isn't touching the timing cover.
Someone has to know what causes this......:lecture:

 

[Clean Racing]

What OIL pump do you have on it?? My hi volume in the stroker makes noise due to the tight tolerance at the pan. I have A new stock pump, just waiting till the next oil change to swap it.

 

[clunk]

It's the stock oil pump, has around 108k miles on it. The engine is stock, I opened the bottom end up around a year ago to replace the RMS, checked the bearings and had a quick look at the timing chain. I didn't give it much thought because it was my first time into an engine, but the timing chain seemed a little loose at the time.

 

[CaliGold]

Don't forget the simple things first. Taking 5 minutes to remove the belt, and starting the motor will reveal if it's internal engine noise or one of the accessories. Gives you much more info to narrow down the problem.

If it's a gurgling - grinding sound, I would check the water pump first (with enjine off) by spinning it as fast as you can after you take the belt off.

 

[clunk]

It's a high pitched, metallic rattling noise-basically sounds like a few marbles being shaken at a few thousand RPM. It also doesn't make any noise until the engine gets good and hot, and presumably the oil thins. I had originally thought it was a lifter (or two) bleeding down, but I could never pinpoint the noise to the top end. I eventually pulled the valve cover and checked if the lifters were holding a prime and they seemed fine.

 

[CaliGold]

It's a high pitched, metallic rattling noise-basically sounds like a few marbles being shaken at a few thousand RPM. It also doesn't make any noise until the engine gets good and hot, and presumably the oil thins. I had originally thought it was a lifter (or two) bleeding down, but I could never pinpoint the noise to the top end. I eventually pulled the valve cover and checked if the lifters were holding a prime and they seemed fine.

Definitely check the water pump first if it happens when it gets hot and makes that kind of sound. Timing chains last a long time. Could be wrong, but sounds like a water pump to me. Take the belt off and running for about 5 to 10 secs to verify. It will be worth it to check.

 

[CaliGold]

BTW, lifters make a very specific tapping noise. Almost like a small exhaust leak. I've never heard lifters sound like a metallic rattle.

 

[Ecomike]

5speed.
The balancer isn't touching the timing cover.
Someone has to know what causes this......:lecture:

What about some trash in the cat converter rattling around. Sound does travel and bounce around in these beasts. Mine sounds like it is coming from everywhere when it is cold and making maximum noise, but I am sure now it is sticking lifters because I finally hear them stick and unstick during the warm up at idle. I was originally afraid it was rod bearings from the loud knocking sound, but they had already been checked when the oil pump got upgraded.

MMO and Lucas at each oil change has almost totaly eliminated mine during the last 10,000 miles. It now sounds like a sewing maching, and when hot I can barely hear it running at idle now.

One other thought, I recently solved the last of my marble noise problems by restoring the OEM rubber isolators on my exhaust pipe near the engine/tranny section. Prior owners had bolted the exhaust pipe just in front of the cat converter to the damn tranny with perforated metal pipe hanger material. The Exhaust on take off was feeding back noise into the tranny and frame that sounded like rattling marbles. I also discovered my tranny mount at the cross member had no bolts in it, :scared: adding to the bizzare noise.

 

[bcsavage]

It's a high pitched, metallic rattling noise-basically sounds like a few marbles being shaken at a few thousand RPM. It also doesn't make any noise until the engine gets good and hot, and presumably the oil thins. I had originally thought it was a lifter (or two) bleeding down, but I could never pinpoint the noise to the top end. I eventually pulled the valve cover and checked if the lifters were holding a prime and they seemed fine.

are the timing chain tensioners in these motors hydrolic?

 

[clunk]

Definitely check the water pump first if it happens when it gets hot and makes that kind of sound. Timing chains last a long time. Could be wrong, but sounds like a water pump to me. Take the belt off and running for about 5 to 10 secs to verify. It will be worth it to check.

the main problem is that it's very hard to check--the noise is very intermittent at idle even when the engine get's really hot. It's been part of the problem why I havn't been able to track the noise down for so long.

 

[outlander]

I am starting to think this is normal renix timing chain noise.
Mike(user name,89xjgrey)came over today and we were listenening to my noise and he was scratching is head.I told him to fire his renix up and it makes the EXACT same noise from the timing cover!!

bcsavage:The timing chain tensioner is just a rubber block....it's not hydraulic.

 

[clunk]

I am starting to think this is normal renix timing chain noise.
Mike(user name,89xjgrey)came over today and we were listenening to my noise and he was scratching is head.I told him to fire his renix up and it makes the EXACT same noise from the timing cover!!

bcsavage:The timing chain tensioner is just a rubber block....it's not hydraulic.

there is no way I can call the noise mine makes normal. I see so many similiar aged jeeps to mine on the road that purr along silently, and mine does too--until it starts rattling away, then it sounds like it's going to spontaniously combust.

 

[outlander]

So the noise isn't constant?
I would suspect a lifter that is bleeding pressure.Do a vacuum test.Also as I recommended earlier take the belt off and run it to rule out waterpump,alt,pulley noise.
Accessory noise can sound really bad....