Squeak with Defrost on..

[thatoneguysean]

It tends to only come around in the winter (cold) months, but when i have my defrost button pressed and run the defrost function on the switch my car will have a squeak when i idle or start to slow down, but if i turn the button off and move the switch to say just the foot vents then the squeak is gone.. whats going on?

 

[diss3ntienc]

It could be the alternator serpentine belt. Same thing happened to me everytime i ran something extra that drew power in the winter (heater, defrost).

have a look at it and see if its tensioned properly, if you can't tension it anymroe, i suggest your replace it

 

[CheeseHelmet]

Are you talking about the rear window defrost button? If so then I agree with diss3ntienc, your alternator belt is loose or worn and in need of replacing.

 

[Silverfox]

Another thing to consider is your battery could be getting weak causing the alternator to have a bigger amp draw when you have accessories on, you want to be careful you don't over tighten your belt. You don't want to wear out the alt bearing by over tightening the belt to mask another problem.

 

[tweety2300]

Could be the ac belt as well The car will run the ac when you have the defrost on to de moisturize the air

 

[JayG1989]

I get the same annoying ass squeek before my car warms up. Most common when I have air pumping/heat/defrost. It will get really loud for like 15 seconds and then shhhhhh silence. Sounds like the serpentine belt to me.

 

[tweety2300]

Just replace both belts and be done with it they're like 10 bucks a piece

 

[SoCalMP5]

LOL, I have the same thing. Only when the car is cold. I get that nasty shrieking sound until I rev it up past a certain RPM, or until the car is warm. Then it's quiet. My belts look to be in OK shape, but I'll be replacing both of them as soon as I can find the time. It's embarrassing with everyone looking at my beat-up P5 when it screams like that.

 

[thatoneguysean]

I got all my belts replaced when I got a new timing belt (around 2.5k mi. ago) so I don't see how worn out belts could be the problem. What is the correct tension for the belts?

SoCalMP5: its more embarrassing when the car looks nice and sounds like s***... lol people always looking at me like wtf...? (boom06)

 

[Tamn]

Its the belts. Might try spraying them with a belt spray after making sure its tightened right. No idea what its called, but its always worked well for me.

 

[JayG1989]

Bellingham, FTW!

What spray? It's funny you mention kind of lubricating it. Up at Lake Chelan we had a boat that ALWAYS had a squeeky belt, every time you turned it on and it warmed up. Our little trick was to take a bar of soap and push it up against the side that has the ridges. The soap would kind of break away onto the belt and it would become immediately silent...

The thing is that this was a short term, temporary fix, as opposed to never having to deal with a damn belt.

 

[Tamn]

Haha yeaaa more bellingham p5's. Gotta start a cult.

Yea Prestone Belt dressing spray can get it at walmart. Its probably only a temp solution, but I find it works well when i re tighten the belts.

 

[tweety2300]

It will glaze the belts and then you'll have to replace them. You shouldn't be able to twist the belts more than 1/4 of a turn. The belts probly just stretched a lil bit no big deal just tighten them

 

[JiggaBro]

It will glaze the belts and then you'll have to replace them. You shouldn't be able to twist the belts more than 1/4 of a turn. The belts probly just stretched a lil bit no big deal just tighten them

+1

just tighten the inner belt a little until it goes away (i put it on ramps and would turn on all electrical components to try to make it squeak)

 

[CheeseHelmet]

I got all my belts replaced when I got a new timing belt (around 2.5k mi. ago) so I don't see how worn out belts could be the problem. What is the correct tension for the belts?

Then it's definitely a loose belt, generally the belts will stretch a bit after they're installed. It's perfectly normal for them to start squealing after a couple thousand miles, once you re-tighten them they'll stop making noise for good. The correct tension is available in the service manual, a good rule of thumb is that you should have at most 1cm of deflection when pressing down on the belt with moderate force in the middle of the top two pulleys.

Don't use any kind of "belt spray", that's just a stupid waste of money.

 

[xitoxic]

my car has been doing this for like a year and i just didn't bother fixing it cause i got a belt and that never helped so i stopped caring. but could anyone tell me how to tighten the belts to stop the squeaking? help is appreciated thanks.

 

[xitoxic]

anyone? i would love to fix the squeak problem

 

[CheeseHelmet]

my car has been doing this for like a year and i just didn't bother fixing it cause i got a belt and that never helped so i stopped caring. but could anyone tell me how to tighten the belts to stop the squeaking? help is appreciated thanks.

If you've waited a year the belt is probably finished, I doubt tightening it will help much. The procedure for tightening the belt can be found in the service manual. In order to access the alternator belt tensioner you're better off lifting the front end of the car and removing the strut tower bar and the cruise control actuator. That way you'll be able to easily access all 3 bolts that need to loosened/tightened to get the job done.

 

[xitoxic]

the year thing was me just blowing it out of proportion, hahah. but thanks man

 

[masmech]

Squeal may be the power steering pump

It tends to only come around in the winter (cold) months, but when i have my defrost button pressed and run the defrost function on the switch my car will have a squeak when i idle or start to slow down, but if i turn the button off and move the switch to say just the foot vents then the squeak is gone.. whats going on?

Even though the squeal happens when you turn on the AC or the Defrost (which also uses AC), it could be the power steering pump. On my Mazda, the PS and AC are on one belt and the Alt and WP are on another (good setup). Here is a test. When cold on first startup, turn the steering wheel left and right several times. If the belt squeals it is the PS pump. Of the belt does not squeal, try the AC or defrost and see if there is a noise. If there is a noise, turn the steering back and forth a few times. If the noise stops, it is likely the PS pump. There is a possible cheap fix. Buy some Lucas power steering additive and follow directions, that may sure the squeal or make it better. I know it is hard to understand how the PS pump can cause the belt to squeal when you turn on the AC, but that is possible due to the belt setup if it is the same as mine.
Here is how you can test the AC compressor. With the engine running and the AC on max and compressor engaged, use a pump sprayer to spray water mist in the AC pulley groves. If the AC compressor pulley tries to engage but slips and starts and stops (you can see it do this), it is probably OK and the bearings are fine. If the AC compressor pulley just sits there while the belt slips by, it may be the AC compressor.
If you have two belts and want to pinpoint whether the squeal is the Alternator or AC belt, the crank pulley has two areas. Target the AC/power steering groves first with a directed spray of WD 40. If the squeal stops, it is NOT the alternator or water pump.
If you have the ridiculous crap serpentine belt (you poor thing because one belt fails and leaves you on the side of the road. AC's will seize, pop the belt, and you suffer THE BLACK DEATH! which means your car will be towed) target the power steering pulley grove, then the others with WD40 until the squeal goes away and you locate the source.
In most cases it will be the belt, or the power steering pump that is causing the noise if your AC compressor runs smoothly and your AC is cold.