rev up your engines, today I'm gonna talk about the horrid noise of squealing or
rattling fan belts or pulleys that drive them on your car, now I'm an old timer
and I call them fan belts, because the belt used to drive the mechanical fan
that cooled the radiator, now today cars all have electric cooling fans most of
them, and these are technically called drive belt because they drive
accessories, but I'm still calling them fan belts, now in your noises like that
or squealing noises in this case it's easy to know which one it is, because it
did it when I turned the wheel, so you know something's wrong with a fan belt
that runs the power steering, and in this case it was very easy to pinpoint, the
extensioner fell apart on it so I had to put a new tensioner in, and no big deal it's
got two bolts that hold it in, but this is an older car that has a multi belt
system it has three belts on it, one runs the AC way down there, one runs the
alternator, and the other one runs the power steering pump, so on older cars
it's real simple all you have to do is check the belts one at a time, if you got
a noise take the one belt off, the noise goes away great, if not then take the
next one off and then take the next one off, and then when a noise stops you know
that's the system that's making the noise, but most moderate cars they only use one
gigantic serpentine belt, like just Toyota Matrix and it's 12 years old, it's
got one giant belt and then hidden way inside here down in here is an automatic
tensioner that automatically makes the belt tight, here such an automatic
tensioner, inside is a giant spring and the spring pushes the pulley against the
serpentine belt, so you never have to readjust it yourself and automatically
adjust itself, on an older car like this old Civic, you can see there's adjusting
bolts here, all the fan belts have to be adjusted every once in a while, you
loosen these bolts, then you tighten the adjuster, until you get the right amount
of deflection on the belt, then it won't make any noise, so these older cars
required more maintenance you had adjust the belts every once in a while, and the
big hassle was, if there were two loose they'd squeal, but if they were too tight
they can actually burn out the bearings, you could ruin a power steering pump, you
can ruin an alternator or a water pump if you got them too tight, now you don't
have to worry about that on a modern car because the tensioners automatically
tensions it, but of course over time as they age the tensioners can wear out
or the belt can wear out and start to make noise, now when this tension went
bad it was simple, because you could see the fan belt was wobbling on it was rattling
making a lot of noise, but sometimes the bearing starts to wear inside and you
don't see anything obvious, so here's a trick I learned years ago, if you think
the tensioner is going bad and making a noise, get some wd-40 spray it on the inside of
the tensioner where the bearings are, then if you start it up and the noise
goes away,
you got a pretty good idea that the bearings on the tensioner are just worn and
it's time to replace it, before it breaks and throws things all over the place, now
you do want inspect the belts as you see here this one's full of crack, so it's
long gone it, should have been replaced a long time before they were all cracked
but here's something you might not know, since they're serpentine belts and they fit
on grooves, the belt has to fit the grooves perfectly and the depth is such that
the grooves and that inside the belt are riding on the pulley perfectly, but as
they wear the grooves actually get deeper, which is a bad thing because then
you're only riding on the edge of the groove and it's not seated in and then
they can slip and make noise even if they look okay, so if you have a modern
car and the fan belt isn't cracked with one of these serpentine belts and the
tensioner is fine, and you don't see it wobbling all over the place because it's
too loose and it's just running smooth, but it still makes a squealing noise you
just need to put a new fan belt on, because as I said after many years of
driving, the grooves just wear too deep, then the belt doesn't sit right, so if
you got a belt that's been on there are eight or ten years and starts making
the noise, just changes the thing even if it isn't cracked and here's a
warning of something not to do, they make various belt conditioners that say
they stop squealing and stuff and condition the belts, they're basically a
very sticky substance, and my warning is this don't ever use any of these things
they just cause more problems, and if they're masking a problem, let's say your
belt is worn and you put this on and then the sticky stuff makes it grip
better, you might be in the middle of vacation somewhere, then the old belt
just breaks and you're stranded, don't use these conditioners they're just a
stopgap measure, and actually if you spray too much on it and you get them on
the electronic sensors, you can actually damage the car, back when I was a kid we'd
even use a bar of soap and when the cars running if you stuck the soap on an old
fan belt, it would quite it down for a while, but really it's not a fix and with
modern cars generally only having one fan belt on them, you don't want to get stuck
in the middle of nowhere, so if you're hearing noise, fix it just don't
mask it with some kind of sealer or even a bar of soap rubbed on it to make it go
smoothly, because really these modern serpentine belts, they're pretty well
made, this is a 12-year old Toyota Matrix, still has the original belt on it
doesn't make any noise, it isn't cracked, so when they do have a problem,
just replace the stupid things, it's easy enough to do on these one belt systems
because all you got to do is make the one tension or go loose, and then replace
the thing, now you might need a special tool but hey places like autozone, they'll
even loan you one free, but here's a trick if you're going to change your own fan
belt, get your phone and take a picture of what it looks like on the vehicle
because they used to be nice on cars and under the hood of your car with the
picture of the fan belt and everything it went around, so you know how to put it
back right, but unfortunately most manufacturers they got stickers but they
don't have the pictures of the fan belt anymore sitting on the frame somewhere
like they used to, so since they go over so many pulleys take a picture of it
first, so now you know all about fan belts and tensioner pulleys and how to
fix them when they start making noise, so if you never want to miss another one of
my new car repair videos, remember to ring that Bell!