Replaced serpentine belt, now squeaking

[BlazerFarm]

I wanted to see if I could get your guys' take on this. I replaced the serpentine belt on my 1990 with an AC Delco replacement (6K970). The belt is the right size. There's ok slack. The tensioner seems fine and everything lines up. The belt went on with no issues. However, right after replacing the belt I started getting a squeaking sound from what seems like the AC compressor. It squeaks whether or not the AC is on.

I tried the screwdriver to the ear trick on the compressor, tensioner, water pump, and alternator but can't hear any squeaks through the screwdriver. So I'm having a hard time pinpointing where the heck it's coming from. It's also quite odd that it would start when I replaced the belt. I never had any noise like this before.

I've been reading online where people have this issue sometimes when they replace the serpentine belts. I've never heard of it before. So I thought I'd see if anyone here has any ideas.

 

[MEANSTREAK K30]

Even though the tensioner seems allright, that might be the culprit. The noise might go away as the belt wears in . Mine used to make this noise every time it rained. I used to put a little bar soap on it to get it to shut up cause I was too lazy // cheap to fix it right.

 

[diesel4me]

I've seen new serpentine belts that went "eek--eek-eek" for a few weeks after being installed,when the previous one was silent,and all the idlers were good ...some belts have what appears to be ground glass in with the rubber,and those squeak the worst..sometimes the squeal fades after awhile,sometimes it doesn't..

Gates and Goodyear belts seemed to be the most likely to squeak--one Gates my friend put on a Mazda for a customer screeched like hell right after a start,like it was slipping due to the altenator putting out a healthy charge to boost the battery back up after starting it...2-3 minutes later the squealing would subside...

He told the customer he checked the alternator,and it put out almost 15 volts after a start up--suggested it may have a bad regulator...customer opted to replace the altenator--after installing it (a real pain too!)--he had zero improvement--it did the same thing...the pulleys all looked perfect,not glazed or worn,rusty,etc and the idler was replaced previously not that long before too--he tried another new Dayco belt,a Goodyear,then finally after having the customer pestering him ,he went to a Mazda dealer and got a OEM belt...

The first time he started it that one squealed like a stuck pig!--then it went away,and was silent afterwards...he was glad to see that car leave..he tells me several Fords he has replaced the serpentine belts on, squeal almost every time without fail...some customers live with the noise,others squawk and want it gone...

 

[BlazerFarm]

Yeah, it's just quite odd. The first test drive was fine until I got home and I could hear it faintly. It seems to be getting a bit worse. I'll try the bar soap to see if that stops the squeaking. If it does then that would point to the belt being the culprit. I just don't want something to grenade because I'm thinking I have a belt squeak when it's actually a bearing somewhere.

 

[mrk5]

I had a Super Duty that I replaced the belt on shortly after we bought it. Few months later started to get a squeal at high RPM. Tried replacing stuff I thought it could be including tensioner. Always disregarded the belt because I had put on a good quality Napa belt.

Chased the squeal for over a year. Finally decided to buy a Ford Motorsport replacement belt and the problem went away. It was an $80 belt but I had spent more than that chasing the cause.

AC Delco should be a good brand but you never know.

 

[BlazerFarm]

Ok, I tried the old Windex trick. Spray some glass cleaner on the belt (since it evaporates fast) to see if it's the belt squeaking or something else. It's the belt. I'll give it a bit to see if it'll go away, then I may replace the belt again. We'll see. Thanks for the tips guys.