Timing Chain . . .2nd time less than year!

Needless to say I'm both P***ed and baffled by this. Timing chains are supposed to last the life of the vehicle. I changed mine at 112k less than a year ago. Now at around 117k am starting to hear the thing acting up in the same way again . . .the same high pitched sound when hitting the gas pedal, but only when the engine gets up to operating temperature. WTF!

BTW I changed out the entire timing chain kit, including the chain, tensioner, sprockets and cover. when I opened it up, it seemed that the chain was good but the plastic tensioner thing was shot.

Before I relive this crappy rerun, my question is: WHAT WOULD CAUSE A TIMING CHAIN TO CRAP OUT IN LESS THAN A YEAR (5K miles)?

Please give me some ideas here! I don't have nearly the wisdom (or money) to figure this out. The only thing I could think of is its not getting enough oil? My oil pressure does dip to 10psi @ hot idle (although it goes up right away to about 15-20 once stopped). While driving it is at 40-50psi.

Othewise, the jeep runs absolutly wonderfully . . .I would say like new. Its pickup is sick and it has alot of acceleration left even at 80mph. But i don't feel right driving it from New Jersey to Maine with it like this.

Sorry for the long post . . . Much appeciated!

Timing CHAIN? XJs have a timing belt. They definitely can prematurely fail if improperly installed. You might want to post some releveant info ie engine and vehicle. IF it is a chain and is beginning to fail within 5k it would have to be defective part or improper install I would think.

Oh sorry, it is a 98 xj 4.0. It definitly has a Timing Chain, as do (to my knowledge) all Xjs. Well, a defective part and/or improper install would cause premature failure. But a pro mechanic helped me install it and it was just fine untill two days ago. Still, what makes me think something else is causing it is this: 1) for a timing chain to fail even at 115k is strange and 2) 5k later it is showing the same symptoms. Why?

Your first failure is strange, let alone the repeat. Something else must be terribly wrong for this to be happening......have you ever hydrolocked?? how true are the crank and cam shafts??

NWPhotog said:

Timing CHAIN? XJs have a timing belt. They definitely can prematurely fail if improperly installed. You might want to post some releveant info ie engine and vehicle. IF it is a chain and is beginning to fail within 5k it would have to be defective part or improper install I would think.

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mjma said:

Your first failure is strange, let alone the repeat. Something else must be terribly wrong for this to be happening......have you ever hydrolocked?? how true are the crank and cam shafts??

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Never hydrolocked, at least since I owned it . . .'bout two years and 12k miles ago. To my very limited knowledge, the crank and cam shafts Seem to be working fine. But i do get the typicall 4.0 chatter when the engine is warming to op temp. And I do get what I believe to be a lifter tick under load (but may be a small exhaust leak). I don't know, maybe my problems are all related. Still, the engine runs strong.

they definitely have a chain i am in the process of rebuilding my 01 (putting new cam lifters oil pump and cam bearings and timing set) i hope this doesnt happen to me.

but i cant help you out on this one seems really strange

NWPhotog said:

Timing CHAIN? XJs have a timing belt. They definitely can prematurely fail if improperly installed. You might want to post some releveant info ie engine and vehicle. IF it is a chain and is beginning to fail within 5k it would have to be defective part or improper install I would think.

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Maybe you should stop giving tech advice until after you've seen an XJ firsthand.


:cheers:

In the parts diagram above did you instal the cam button and spring(#12 in the diagram)
It keeps the cam from walking out and causing a misalignment with the timing set and possibly accelerating chain/gear wear.

Do you have the oil slinger installed on the crank???It sandwiches in between the crankshaft balancer and the crank timing gear

Check the crankshaft endplay.

outlander said:

In the parts diagram above did you instal the cam button and spring(#12 in the diagram)
It keeps the cam from walking out and causing a misalignment with the timing set and possibly accelerating chain/gear wear.

Do you have the oil slinger installed on the crank???It sandwiches in between the crankshaft balancer and the crank timing gear

Click to expand...

I did the cam button and spring, it came with the set.

The oil slinger I don't remember. I guess that literaly slings oil onto the chain. It would make sense if that was the culprit. Son of a b****!

kcjeep6 said:

Check the crankshaft endplay.

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excuse my ignorance but, what is that?

that would be how much it moves laterally...

...meaning front to rear movement of the crankshaft in the block

blaisetd said:

that would be how much it moves laterally...

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duhh! i was thinking it was a part.

Firewater said:

I did the cam button and spring, it came with the set.

The oil slinger I don't remember. I guess that literaly slings oil onto the chain. It would make sense if that was the culprit. Son of a b****!

Click to expand...

Yea you'll find out for sure when you get it apart.Both the cam button/spring and the oil slinger are items that are easily forgotten......I forgot to install the cam button when I dropped in my fresh motor.Found that out when I tore into the timing set to find out why I had timing set noise.
Installed cam button and fresh timing set and noise still persists...IDK.

BTW there are two different types of timing sets available.One is a single roller type and the other is "SILENT" type(the one I currently have in there) that is more beefier and supposedly more quiet by design.I couldn't tell a difference between the two.
You might as well get the silent type to for a replacement if you don't have it already....

Well, I guess it is what it is. but damn! How annoying. I just hope the cam is alright. I will def get the "silent" type. God only knows what I will do if I fix it again and it starts to make noise!

Thanks for all the advice.

It"s very frustrating!!
I was having timing chain noise and like I said I went through the trouble of replacing the timing set only to still have the same noise when I got done