Help with squealing noise

I have a 1995 Saturn that makes a squealing noise when driving.

Situations:
- usually when the car is starting up. I've noticed that if I run the
car for a while and stop it for just a few minutes, the squealing
doesn't appear when I restart the car. If I let it sit while I'm at
work, it is more likely to come back. It does NOT always happen
though.
- happens for a random amount of time, usually a few minutes.
Sometimes it appears again after I've waited at a traffic light.
- eventually when I'm driving, it does go away. usually after a few
minutes.
- if I slow down enough (to maybe a few miles an hour), I can make out
that the squealing isn't constant but rather comes and goes, almost
like a sine wave.
- no noise when the car is stopped.

My mechanic replaced the belt a while back which did cure the problem
for a few weeks but now it has returned.

Any ideas? What should I tell my mechanic to look for/replace?

Thanks.

 

Could be the belt. Try spraying some belt dressing on it and see if it goes
away. About $3.00 from WallyMart.

 

Sounds like the belt tensioner is weak.

 

My '94 had a TSB way back when it was new for similiar symptoms. It was the
idler pulley that needed replacement.

Lane [ l a n e @ p a i r . c o m ]

 

My 92 SL2 also squealed in cold weather last year. Replacing the serp
belt with a new one did not help.

I have read about the bad tensioner being a prime suspect for causing
squealing, and decided to just live with it till it becomes unbearable.

But, about 3 months ago, I replaced the water pump since this car is 12
years old w/ 121 k miles, just for peace of mind. And now, no more
squealing in any kind of weather.

The short of it: it might be the tensioner, but it might also be a water
pump that is starting to fail.


=================================

" ..... I ain't no bandleader!!"

 

If it happens more with the headlights and heater on, that's when the
alternator is working the hardest. The highest torque load that the
alternator draws is at idle. More likely here to cause some belt slip and
squealing.

Check the belt for any shiny surfaces (glazing) or cracks. For either
condition the belt should be replaced. Also check the tensioner. It is
supposed to be automatic tensioning but I've seen a few where the spring
snapped and it lost some of the tensioning force.

Belt dressing is only a temporary fix. I tried it once and it lasted two
days... Then I replaced the belt.

On another car, a bad alternator (shorted diode which cooked the stator
assy) caused an ever worsening belt squeal. Got so bad that I pulled over
and yanked the plugs off of the alternator and quickly drove to buy another
alternator. Replaced the second failed nipondenso (OEM)with a Bosch(?)
equivalent and it never failed again.

Oppie
'01 LW300

For valid response address, remove the '1' following oppie
_________________
| I have a 1995 Saturn that makes a squealing noise when driving.
s.

 

If your tensioner is bad you should replace it immediatly because it is very
possible for it to leave you stranded. Couple years ago when I had the belt off
for some reason, when I put it back on I thought that the tensioner felt a
little weird. Worked it back and forth again and it seemed fine. Probably about
a month later, I'm sitting at a red light(radio up) and I see the battery light
flashing. I turn the radio down, and give it a little gas to see if the light
turns out. Well, it made a horrific grinding noise. Luckily I was turning into
the restaurant where I was going anyway, so I popped the hood and found that
the belt was totally loose, and the grinding was actually belt slip. So I get a
ride to autozone, pick up a tensioner, and change it in the parking lot.
So, moral of the story, if you think your tensioner might be hurt, change it
before it bites you.

You might have 'helped' your tensioner when you changed the pump......

I would tend to doubt the water pump. Its most likely the tensioner.

 

I agree that it is more likely that it would be the tensioner, just
sharing my water pump experience , for what it's worth, in case someone
replaces their tensioner still has noise.

While I had everything apart, I fiddled with the tensioner and as far as
I can tell it is OK. The old pump did have a rough feel when turned,
and some side to side & in/out play when compared to the new one.
Whether the play / roughness is normal or excessive for this car's
age/mileage, I don't know. But that's what led me to conclude that the
pump was wearing out & was the squealing source, since it is now
completely gone.


=================================

" ..... I ain't no bandleader!!"

 

I'm with you on this one. Water pump might be a bit stiff when cold but
never should feel rough when turned. Any shaft play, either radial or axial
means that the bearings are about to fail. When under mecahnical load from
the belt, possibly the balls in the bearing started to jam against one
another and that was the cause of the increased torque load which caused the
squeal.

Before automatic tensioners, the most common cause of water pump failures
was an over-tightened fan belt or an out of balance fan. those days are
gone.

Oppie