Eliminating Alternator/Serpentine Belt Noise

[USMCtacoma]

I drive a 2004 Tacoma Pre-Runner doublecab with 45K miles on it. I've noticed a chirping/squeaking under the hood when I start up the truck in the morning (on cold days especially) and through out the day. The chirping/squeaking go away when I step on the gas and drive, but when I take my foot off it starts up again. It is not loud and annoying, but I can hear the noise from inside. There is no problem with performance and I've had the belts checked for tightness and everything is ok. I've read things about putting soap on the belt, etc. to eliminate the noise, but I've heard that is temporary. Any help would be great, it is starting to worry me.

[Flash75]

You can buy belt dressing for squeaks but I have never had much luck using it. Of course it's worth trying. Are you sure it's the alternator belt? There should be three belts on you engine, the shop manual shows three on both 4 and six cylinder engines. You may have to replace the belt to stop the noise. On older cars/trucks you can temporarily remove a belt to help locate noises. On OBDII engines you may create a check engine light if a belt is removed. Another possible source for the problem is the fan clutch.

Clifton

[jessematt]

I had the same problem with my 2004 Tacoma Double-Cab about this time last year. Had about 40,000 miles on. Same symptoms you mentioned. Had the serpentine belt changed, problem solved.

[Steve762us]

Belt dressing always made squeaking worse, IME. Best solution (when the belt is in no need of replacement, or new): silicone lube spray. Sounds illogical..but works a treat.

[bangbg]

Are you sure the noise is coming from under the hood?

The 2 piece drive shaft has 5-7 zirc fitting on the U-joints as well as the slip yoke that need regular lubrication. The noise it makes when it dries out is the same as a sqealing belt, but it comes from the rear of the truck. It makes the most noise when you take your foot off the gas or are coasting on hills with your foot off the gas but in gear, and goes away when you accelerate.

May be the serpentine belt, but if that doesn't help, I would check out the driveshaft.

[HotRod53]

If it is the serpentine belt, and it very well could be, go out and buy a Goodyear Gator-Back belt. This is the only one that I could find that runs quiet and is guaranteed for life to do so! Around here Frank's Auto Supermarket sells them. These are designed unlike any other belt you have replaced before. I have used 2-3 of them and have recommended them to many friends, it has never given a cause for a complaint! I have used AC/Delco, NAPA, and a genaric brand..Gatorback is #1!

If you have already used belt dressing.... remove the belt, go to the edge of the trash can, do a slam dunk.... it's toast!