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Timing Chain Noise at Cold Start

9K views 16 replies 5 participants last post by  smokeman 
#1 ·
Need some help on a noisy timing chain.

Specs.: 1996 Jeep Cherokee Country 2wd
Mileage: 170k

Recently replaced my front crank seal and noticed a great deal of slack in the timing chain. Decided to replace with an OEM Cloyes timing chain since I was in there. Ever since replacement, the timing chain makes alot of slapping noise at very cold startup. Once warmed up, the chain noise goes away. Any ideas? Maybe an oiling issue at cold startup?

Thanks

By the way, I did put the camshaft spring pin back in on replacement.
 
#2 ·
Was the plastic chain dampener still in the cover? This prevents slack from chattering around too much. Sometimes, these will be worn down beyond recognition.
 
#5 ·
Replaced gears and chain. Could the oil slinger be that loud if it was wobbling on the crank nose? It was pretty loose even when slid over the woodruff key on the nose. I just don't understand why it gets so quiet once it warms up after a couple of minutes.
 
#8 ·
smokeman said:
Could the oil slinger be that loud if it was wobbling on the crank nose? It was pretty loose even when slid over the woodruff key on the nose.
The oil slinger should have been tightened up when you put the balancer on and torqued the crankshaft bolt. It gets squeezed between the balancer and chain sprocket. (Which is not to say that you could hear it if it was loose.)

How did you center the timing chain cover before you tightened it down?
 
#10 ·
tangofox007 said:
How did you center the timing chain cover before you tightened it down?
Timing chain cover is centered easily through 3 or 4 shoulder alignment bolts, THEN you can install the rest of the regular bolts..
 
#11 ·
Jeds Sr. said:
Doesn't sound like an oiling issue. You should have more pressure when the engine is cold... :confused:
When I say oiling issue, I mean maybe it is taking time for oil to splash the gears, chain, and cover when cold startup after sitting overnight. I thought this because the noise dies off after a couple of minutes. Also, it only does it on first startup in the morning so I thought maybe the oil needed time to thin out which is why the noise would die off after a couple of minutes.
 
#12 · (Edited)
mickdawg777 said:
Timing chain cover is centered easily through 3 or 4 shoulder alignment bolts, THEN you can install the rest of the regular bolts..
Not according to the service manual. There is an alignment tool that centers the cover at the crankshaft. Alternatively, you can install the balancer, then remove it to tighten the bolts behind it.

I was not asking how to do the job; I was asking smokeman how he did it. If the cover was not properly centered, it is conceivable that the chain is making contact with the cover. Plus, the crankshaft seal will probably leak.
 
#13 ·
tangofox007 said:
Not according to the service manual. There is an alignment tool that centers the cover at the crankshaft. Alternatively, you can install the balancer, then remove it to tighten the bolts behind it.

I was not asking how to do the job; I was asking smokeman how he did it. If the cover was not properly centered, it is conceivable that the chain is asking contact with the cover. Plus, the crankshaft seal will probably leak.
Thanks, I appreciate the idea but it seemed to align with no issues. Also, the front seal, so far, is completely leak free. Another thought I had was that the old cam gear had an indent that was exposed outside of the cam gear washer. I wondered if the indent was to allow immediate oiling of the chain from oil passing over the camshaft through the front hole of the cam. The new Cloyes cam gear did not have this indent and the washer completely covers the camshaft oiling hole. Would this cause an oiling problem on initial startup of the engine after cooling overnight?
 
#14 ·
I have a '05 Rubicon with 22k miles and a noisy timing chain as well. Being under warranty I've taken it to the dealer a couple of times without success. They say it's not unusual for the 4.0s and it's not noisy enough to justify replacing it. It sounds like a diesel when it's first fired up and then a dull rattle while crusing. It's driving me nuts so I'm going to order the parts and do it myself. My wife's '06 has 20k miles and purrs.....
 
#15 ·
Well, I figured my issue out. When I replaced my gears and chain, the cam walked out about 1/4 inch when torqueing the cam bolt down. That is why the chain was slapping the cover. When I took it back apart a few days later, I noticed the cam was sticking out and used a rubber mallet to tap it completely flush again. Also, noticed that the Cloyes cam gear has vertical space between its depression and the cam washer to allow oil to splash on the gears so there was never a oiling clearance issue. Anyway, thought I would update in case anybody else had similar questions or issues. My chain slap is no more. Now I just need to fix those sticky lifters. :brickwall
 
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