Name That Sound
 

Listen to the audio file and see if you can identify the source of the noise. What do you think it is that's making that sound (from the engine - not the commentator)? Cheers!

Possibly a loose cam chain?

sounds like a loose flexplate to me.

Mine was making the same noise a while back. It was a failing water pump.

I thought it was the water pump but the noise emanates more from the passenger front corner of the engine than from front & center. I used a long extension as my noise probe up against my cheekbone and touched on everything I could reach safely on a running engine. Later I had the opportunity to check it with a stethoscope and it made me suspect something other than water pump. The wife and I are due for a White Mountains road-trip next week and into New Years weekend. I'm flat-out with family matters, Christmas and general holiday and winter prep, so I brought it to the corner shop (good guys) and asked them to diagnose/address the noise. They seem to think that the noise source is the belt idler/tensioner (confirmed my suspicion). As far as replacement is concerned, they claimed that Chrysler made a change to the idler design that caused a change to the belt length. I think they quoted $125 and told me it would be ready tomorrow noon - that $125 might be just the cost of parts - but it seems like a good start so I told them to go ahead and do it. It's a small enough price to pay (at this point) for a degree of confidence without delving into water pump and associated details right out of the gate. If it stops the noise then we will have eliminated it with less investment and I'll be all set. If it doesn't stop the noise then we can find the source more readily next time. If it is the W/P then I'll still have enough time to go all-in on it before the trip. The next challenge is figuring how I'm going to pay for everything without sacrificing my beer money.

We all must make sacrifices to drive a jeep! LOL! Between paying my mortgage, utilities, buying food, and keeping my jeep running, I'm tapped out this Christmas. Just last week, I had to replace my house water heater.

I hope this problem is just the belt tensioner. I've heard there can be a problem with the cam chain idlers as well. Good luck.

I had to do it. Normally I'd be singing the "shoulda-coulda-woulda" song by now but must convince myself that I had no choice. No crying over spilled milk allowed. But wouldn't ya' know it, I let them replace a belt and tensioner/idler assembly for nothing. I found that was not the noise-maker too many dollars after the fact. The trip to-from the mountains was a problem-free 500 mile pleasure cruise and this last week since was fine as well - except for the lock solenoid, panel fasteners and now cruise control.

Tonight, while looking for the speed control servo, my "name that sound" noise was really prevalent so I searched more and it was revealed. The stinking fan clutch is doing it. It's almost ready to croak but I must drive on it anyway because I cannot do anything about it until the weekend. I just ordered the replacement - a Hayden fan clutch off Amazon - should be in my hands by Thursday. What's the risk (?) with 75 miles round trip every day, 55 of that is highway, and daytime air temperature's cool enough so that if my fan clutch fails completely at least it is unlikely to result in an overheat for lack of moving the air. It would not be the first time I ran on a prayer. Is this rationale flawed?

The replacement fan clutch arrived Thursday. I carved out the time I needed to replace it. Borrowed the recommended loaner tool kit from AutoZone and ready to get 'er done. Arrggghhh! The tool kit does not include a fan clutch spanner wrench nor do they have one to loan. The tool costs ~$35 and I'll probably use it only one time. Do any of you have a clever trick or workaround to share for holding the water pump pulley while unscrewing the fan clutch from the threaded shaft?

Where there's a will, there's a way. I made my own water pump pulley spanner tool from a piece of flat bar stock and a couple bolts. Easy fan clutch replacement once you have the tool.

Sometimes you can't keep up with factory changes thru the model years and it get VERY confusing.

Case in point; My 2000 Laredo 4.0 has a 2-speed electric fan run by a PCM controlled pulse relay. I thought all 4.7's had hydraulic fans controlled the same way. I realize the "tow package" vehicles had supplemental cooling requirements but wasn't aware of what they were. I was told the reason for removing the clutch fan from the WJ was to decrease the engine's power demands for accessories.

So Cherryoke, I never thought it could be the clutch fan because I wasn't even aware you had one!

Scientifically speaking, why does a thermal power plant even NEED a cooling system? Most of the energy produced by combustion is waste heat! Stone age technology that works.