JD101

Just a few months ago I had all the three belts/water pump replaced with OEM parts on my Civic 2003. Right after this, hear squealing sound for few seconds and then goes away. Took it back to mechanic, he tightened the AC belt twice and says he doesn't want to tightened it further as that may lead to bearing failure.

The squeal sound comes when the engine is cold ( meaning within first few minutes of starting) and the heater fan is turned On in defrost mode. Once the engine is driven for a while then turning on/off heater doesn't produce the sound.

If the heater fan is off then I don't hear this squeal even during first few minutes of starting the engine.

Mechanic now says, it could be dust on AC clutch pulley. What do you guys think? Could it be clutch bearing?

thesushiboy

Could be, but they are very distinct sounds, and if the squeak goes away after the engine warms up, I'd doubt it. A bad bearing really sounds like a loud howl while the belt sounds like a squeak... Can you take a video with sound and post the link here?

JD101

It's hard to take video, as it doesn't squeak all the time and it is very brief like 5 secs or so and then it goes away. It seems like when the temperature is cooler/engine is not warmed up and the AC clutch is engaged then you can hear this squeak. what do you think?

thesushiboy

Generally, belt squeals are caused by bad bearings or water. Not really loose belts. And if a belt is TOO tight, that's a whole different set of problems.

Best GUESS: It's condensation that gets thrown off when the engine starts up. It's cold in the mornings, lots of dew, and it only lasts a few seconds. I wouldn't worry about it. Some schools of thought say shoot some WD-40 on the belt to get the water out of there, but I don't like put anything on the belt that could compromise its strength.

If it's a bearing, man, you'd really hear it and so would your neighbors.

JD101

If it's condensation or water, you would think the squeak would not coincide with turning on heater fan. It would squeak when the fan is not ON. correct?

When weather is warm it doesn't squeak as much.

ezone

Electrical and AC loads causes belt screech? That belt is still not tight enough.

Aftermarket belt? Some tend to stretch out and loosen especially in the first few hundred miles. Some aftermarket belts have shallower V ribs that don't engage the pulley grooves as well as the original belts, and cause slippage problems that way.

JD101

Thanks for you input. All the belts are Honda belts. They were installed few months ago, and I have driven about 800 miles. So I did a test this morning.

I start the car and in few minutes before it is warmed up completely, I turn on the heater fan on and off ( without defrost), you don't hear the squeal. Then I turn on the AC, I hear the squeal, I turn off AC the squeal stops. After few times, you don't hear it again. Then I drive for few minutes, let the engine temperature reach it's maximum, now turning on and off the AC does produce the squeal.

Is there a document that shows the factory specs on belt tensions?

ezone

Sounds to me like you described belt squeal, that alt/ac belt is not tight enough.
Yes.






Oh, you wanted one? Here:

Deflection method involves applying 22 lbs of force to the belt in the location shown by the arrow.

Hiteshrc

I have a 07 Six cylinder Accord .
I get a squealing noise when engine is started in cold weather and would go away after riding a bit.
Recently the noise has increased and it comes on and goes away irrespective of weather and time of the day...
intried turming on and off the ac when the noise happens but it does not eliminate it ...
my mexhanic suspects a bad ac compressor as he said the belt has brown residue due to rubbing
attached is audio noise .. zit is not always as load as it is in the file but this is the worst
thanks for your help

where can I attach the audio file ?

ezone

You've posted in a Civic forum, not Accord....but I'll give it a shot


Upload to youtube or a similar hosting site, and just paste the link into your next post here.

How many miles on it?

A factory EPDM type serpentine belt will turn brown, that's normal and expected and it was probably turning brown 7 years ago. The color alone is not something I worry about.

Has the car had a timing belt job done yet? (8 years/100k miles, whichever comes first) Our shop includes the timing belt hydraulic tensioner and the serpentine belt with the timing belt job.

If your mechanic suspects a compressor issue, that SHOULD be easy to prove --without any guessing.
FYI real compressor failures are very rare, but external compressor parts such as pulley and clutch issues are common and can be fixed without having to replace the entire compressor.



If someone installed an aftermarket belt, is it the wrong length? If it's too long then the automatic tensioner may not be able to keep it tight enough.