My '98 Cream Puff came with an annoying chirping sound at idle that screeches when you blip the throttle & drives me nutz squealing while cruising along. Its a 4.6 4X4 that now has new serpentine belt, tensioner & idler pulley-that made no difference at all. Also reluctantly tried CRC Belt Conditioner, brake clean & carefully cleaned each groove on every pulley w/triangular file. Several highly recommended mechanics have looked/listened. They remain mystified as to the sound's source. Spraying water on grooved side of belt, while idling, silences it for a few seconds, water on smooth side does nothing. With belt off all shafts spin 'smooth as glass'. Also ran w/o belt to eliminate harmonic balancer that looks exceedingly close to timing cover. Theories NOW range from AC clutch to cooling fan clutch to alternator. Truck only has 7500 miles on it & everything seems to work perfectly. Veteran mechanics & parts guys all agree that diagnosing these sounds can be a PITA. Normally I'd suspect the declutching fan, but this gremlin came & went for awhile as the AC cycled. The Belt Conditioner made it especially loud.

 

Only 7,500 miles on a 10 model-year-old truck? Dang!

Or did you mean 75,000?

 

I posted & meant 7500. It was 7579 last time I looked. My 84 YO Dad didn't even put 200 miles on it last year & we just got it inspected in NY. That's why he gave it to me, he hasn't put gas in it since before last winter. He drives an AWD Subaru.

Any suggestions on the squealing that's breaking my hump? Someone recommended a few drops of dish washing detergent on the belt? While I wasn't surprised to be stumped by all the things I tried-I am surprised the professionals who looked at it haven't diagnosed it. Just called on a used alternator to try, but hate to keep throwing parts at it blindly. May remove the declutching fan 1st. Still can't see how wetting the belt could quiet that for a few seconds.

 

Try the fan clutch, mine was squeling bad, of course my 98 has almost 210,000 miles lol . You can rent the tool for like $16 at autozone. Get the tool, remove the fan and clutch and let it sit in the shroud, start it and see it you have any noises. If it was the fan clutch go buy one(about $90 at napa) and replace it.

 

May have found the problem. Believe the harmonic balancer/crank pulley has gone bad. Its hard to judge w/o another to compare to, but it appears that the pulley has moved rearward as far as it can on the rubber insert & may be rubbing against the timing cover. Belt still goes silent when sprayed w/water, but I noticed that when the squealing returns, seconds later, there's a sound I'd thought was the AC engaging. Upon closer examination I realized that the belt was popping up, out of it's grooves on AC pulley & trying to move rearward. Spray some more water, it drops back into the grooves & goes silent. Since you can't get a good look directly inline w/the pulleys, the small misalignment isn't obvious. The belt also runs suspiciously far back on the new tensioner pulley. The ace mechanic who'd looked at it noted the belt was running behind the wear line.

No idea why the harmonic balancer's rubber ring has decided to go on the move-no sign of oil contamination. However, it seems to be the reason the belt wants to jump back. The misalignment appears less than 3/16".

Can anyone post on how much clearance there should be between the crank pulley & the timing cover at the 10 o'clock position, where mine looks in contact with timing cover? Or how the harmonic balancer core/crank pulley assembly should fit together? This unit has the pulley ~1/8" behind the core, guessing a new one has the pulley slightly in front of the core. Presume there's no repair/adjustment or replacement rubber for rebuilding? Ordered replacement for $55, parts guy thinks a coworker's unresolved noise may be the same issue. Any tips for R&R the harmoinc balancer appreciated.

 

Kudos on the low mileage ! I dont really have anything to offer you on the problem, but when replacing that harmonic balancer abosolutely make sure you buy a new bolt if it doesnt already come with it! Those are torque to yield bolts and cannot be reused. just a heads up if you didn't know this already. It would really suck to have a truck w. less than 10k on it with a crank pulley which walks its way loose of the crank and messes it up. GL!

 

New harmonic balancer definitely eliminated the nasty squealing & wasn't to miserable to install. Still took ~4 hours total. Note that once in place there's only about 1/8" clearance behind the pulley. Hard to believe such a small misalignment could make that belt scream so badly. The rear of the pulley had been rubbing on the cast aluminum timing cover at the top & most heavily at the 4 o'clock position. I'd run the bad 1 briefly w/belt off & it was nearly as quiet as it is fixed. Still no conclusion why the pulley worked it's way rearward, best theory is that the rubber ring dried out & shrunk-no sign of oil leakage. Nice to have my 7600 mile Cream Puff running w/o the Screamin' Meanies. The Dorman, made in China, replacement was the only 1 available from 4 parts stores. NAPA got the wrong part in overnite, I needed the VIN to order the correct 8 groove belt. Didn't even ask the Stealership.

 

Did you put some RTV on the keyway of the new damper? If not-you're gonna have an oil leak. Just a heads-up.
JL

 

Kind of late for a "heads-up" don't you think? Fortunately the use of RTV was mentioned in Haynes & you'd need to be blind not to see the old blob of silicone upon disassembly.

 

You'd be suprised at the idiots that don't do it.
JL