Squeak/Squeal Under Hood

KEENA1120

MEMBER
2004 FORD TAURUS
3.0L
6 CYL
AUTOMATIC
140,000 MILES

My car is making a squeaking/squealing noise when I press on the gas. It gets louder the faster I go the louder it gets. The serpentine belt, belt tensioner assembly, alternator, starter, power steering pump, front brakes and back shoes and battery have all been replaced, but the squeaking/squealing will not stop. Can you make any suggestions of what it may be I read the other posts, but I have replaced all the parts that have been mentioned in the previous post. I am afraid if I do not find out what the problem is when it is time for my safety inspection in a few months my car will fail because of the noise. The car runs good and smooth but the noise wont stop. It started after I replaced the battery which was the first thing replaced.

1 Reply

CARADIODOC

MECHANIC
33,916 POSTS

Dribble a little water on the smooth backside of the belt while the noise is occurring. If it changes, start by checking that the tensioner is keeping the belt tight. (Check that with the engine not running). The next thing normally would be to check the belt. It can have up to one crack per inch on the ribbed side. We can skip that since yours is new. The last thing is to determine which pulley is tipped or turned. Most of the time you can sight down from on top. If you look straight down, you should not see the belt peeking out on the lower pulleys. If you do see it off-center on a pulley by as little as 1/16", that pulley or the one right before it is tipped or turned. Most commonly that is an idler pulley. Tensioner pulleys are next most common but those are a little beefier to handle the repeated spring-loaded movement. Being off-center forces the belt to slide across the pulley as it goes around it. That is what makes it squeal. Water can act like a temporary lubricant and make the noise stop for a few seconds, or it can make the belt stick better and squeal much louder.

If you cannot see the belt off-center anywhere relative to where it rounds other pulleys, look for a pulley where the paint is worn off making a shiny silver area that is wider than the belt. That tells you the belt is running in a different location than it was before. When the squeal is a fairly new problem, look for a pulley where the belt is running on an area that still has paint o it. That paint would have been worn off if the belt had always been running there.