2002 Jeep Gr. Cherokee - 4.7L Tim. chain

[Ruger77]

2002 Jeep Grand Cherokee Limited (143,000 miles) in for ticking noise cold, better when warm, but still there. With stethoscope, isolated noise to right bank, front of engine. Suspected timing chain or valvetrain issue, removed valve cover, (customer approved lifters replacement estimate if necessary before vehicle was dropped off) and found major sludge. Ran engine with v.c. off and noise is loudest in top chain guide (that is the guide w/out the tensioner). When turning engine over by hand, chain gets loose then tight every revolution of the crank. My thinking is the tensioner is weak and is being affected by cam load, and warm oil helps it. Any thoughts? Also, I am probably going to reccommend a Jasper due to the heavy sludge. My worry is the oil passages feeding the tensioner, and the possibilty of breaking loose enough gunk to plug the oil pickup. I think I caused an avalanche when I removed the valve cover! I know that these engines are bad for sludging, but this one is worse than I've seen. Maintenance was not good (this oil change is at 7500 miles). My gut says reccommend an engine and ship it, but sounds kind of drastic. Thoughts?

[steven kiser]

you answered your question in your statement. yank it and replace it. messing around with the engine especially after the way you described the maintenance is like putting a gun to your head.

[Tim Martin]

Taking what you posted about the engine at face value, I'd also be recommending a replacement engine. It's difficult to justify major engine work when a Jasper unit can be installed.

[steven kiser]

the customer will probably drop when you give them the price. another tip here is if the customer goes for it i would replace the transmission lines when while its easy. i've found the hard way that once you disturb them they have a habit of leaking.

[ricmorin]

Replace or run.

[Ruger77]

This customer is not one of my favorites anyway. The tough thing is the Jasper option is about 5 times more money than a chain, but you can't rule out damage from all that sludge. My thinking is that the customer will run it the way it is until it breaks (it has been this way for at least a few months). I think I'd rather lose the job and the customer, than to live with this thing on "warranty issues"......... I hate these phone calls......I can't imagine what a doctor must go thru.

[steven kiser]

once you touch it you own it...........

[mopwrforme]

i have tried too remove both v/cs oil pan frt timing area clean all the sludge out then go back with all new tensoners. chains and guides and lifters only too find the passages that feed oil under preasure to not only lfters but the tensoners as well were restricted. basicly at that point i was stuck like chuck. and ended up doing what i should have done to begin with r/r engine completly tore down dipped and cleaned at the machine shop then rebuilt it. then let us not forget if they didnt take care of there vehical before the repair what makes you think they will know.fix it right the first time. i can tell you from experence dont attempt a mayjor repair on a sludge motor. if your not prepaired to do it right. your not doing your customer or your reputation any justice.

[Ruger77]

My thoughts exactly. Thanks for the advice. I brought the customer in today and showed him what the engine looked like while I still had the v.c. off. Of course he blamed synthetic oil, Chrysler, Elvis, and solar flares for the sludge....... Oh well, I'm off the hook on this one. Thanks again for the help.

[steven kiser]

ruger 77 said, "I hate these phone calls......I can't imagine what a doctor must go thru." as a rule situations like this aren't around long enough to really bother doctors. the other point here is that there are pharmaceuticals that the dr's can prescribe that will make you forget what's bothering you. woooo hooooo sign me up............