hi

could anybody help i have a 2009 1.2 skoda fabia and when i switch on my main beam headlights i get a squealing sound from the front left head lamp area noise stops when i turn to full beam or turn to side lights

thanks

Sounds like you may have a loose alternator belt.

With the engine running and said lights on, give the alternator belt a spray of WD40 and see if that cures it.

The belts seem to pull in so much of the damp moisture.

CD

I don't think WD40 would be a good idea on a belt. One of its qualities is lubrication. Belts need friction to operate properly. I would suggest to clean it with some soapy water and rinse well.

Then again, the belt is nowhere near the front left head lamp. It's on the driver's side (on the right).

What type headlights does it have? Is it the ones with the projector or the ones with the reflector? If you have the projector ones, something could possibly be wrong with the mechanism that switches between dipped and main beam. But that's just an assumption. Mine has the reflector ones and there's no moving parts that could possibly squeal.

Sounds like you may have a loose alternator belt.

With the engine running and said lights on, give the alternator belt a spray of WD40 and see if that cures it.

The belts seem to pull in so much of the damp moisture.

CD

Yes the belt may be loose but don't use WD40! Adjust the belt properly. Would you spray WD40 on your brake discs if they squealed?

Brakes and belts need all the friction they can get!

could anybody help i have a 2009 1.2 skoda fabia and when i switch on my main beam headlights i get a squealing sound from the front left head lamp area noise stops when i turn to full beam or turn to side lights

I thought slipping belt at first, but given that noise disappears with change of lights, could it be that the left headlight levelling motor is misbehaving?

Also, I presume you run halogens and not HID (xenons)? HID ballasts can make all sorts of noises, though most can be described as high pitch rather than squealing.

In any case, if you decide it is the belt after all, don't spray WD40 on the belt, as WD40 is oil in a spray can. Clean the belt as described above instead, or with rubbing alcohol (isopropanol/ipa), then tighten.

Sometimes it is not the belt making noise, though, but one of the pulleys/tensioners/bearings.

Edited 23 January, 201313 yr by dieselV6

Interesting one. Never heard of this. Let us know how you get on.

I have heard this from a bulb that was failing before, squeal then TING then darkness

Quote "Yes the belt may be loose but don't use WD40"

There is nothing wrong with spraying the belt with WD40.

I'm not talking of Soaking the belt.

With the engine running SRAY the top of the belt Lightly, this is the outside of the belt.

IF it is the belt holding dampness the Noise will stop or change note.

I have done this for years, and never had a problem with it.

In the end you can determine wether to replace the belt or adjust it.

It helps to diagnose where the noise or fault is.

The belts pull in so much moisture and wd40 helps ruduce that.

CD

Fab59

"I would suggest to clean it with some soapy water and rinse well."

No disagree Fab. This only adds to the problem. The Belt will retain to much dampness.

Norry.

"Would you spray WD40 on your brake discs if they squealed?" NO. This is a completely different situation.

Edited 23 January, 201313 yr by Carlo diesel

Moisture is not really an issue with a belt that's in good condition. Every morning, especially with weather like this, belts will be slightly damp when you first start the car. The heat generated by the engine dries it out soon after though. I'm not talking about excessive amounts, like when going through a very deep puddle, to the point where the belt is submerged in water, that's a different story. Problems start when there is contamination by other substances, or if it becomes loose.

WD40 will help with cleaning any contamination, but it still has lubricating properties, and that effect can stay for a while. In fact, it's a petroleum-based product, and, over time, will degrade rubber. Now, as far as I know, rubber is also petroleum-based, but chemistry is a very complicated science.

Also, I can't see how spraying the outside of the belt would help. The outer side only comes into contact with tensioners, and these just roll freely. They don't drive anything, hence they don't resist the movement of the belt at all, unless their bearing is gone.

I mean, if it works for you, then fine. But personally, I wouldn't recommend it.

I thought slipping belt at first, but given that noise disappears with change of lights, could it be that the left headlight levelling motor is misbehaving?

That's a good idea. I'd move the switch from 0 all the way to 2 (or is it 3?) and then back to 0, to see if anything changes.

sorry for the delay in reply been away with the work!!! car is sorted now went out to it yesterday with a few of your ideas ready to go turned the ignition on and the noise was there had a few tinkers with the light and couldnt get the noise to go got fed up with it and shut the hood down a little too hard in frustration and the noise stopped!! and the light switch works full range again so thanks for all the advice tho guys much appreciated

Hey, I have the same noise from left side head light. Noise appears with head lights, turn off engine and noise still there, sometimes with full and sometimes with dipped. Engine off, headlights on, noise there, switch headlights on while engine off, noise comes back. Takes about a second to appear after turning on light. Has be baffled. Anyone know what it is?

Do you have projector headlights?

I don't know. It's apparently H4 bulbs for the headlight and H7.  How do you tell? It's a Fabia MK2 combi 2009 all stock

Edited 16 February, 20233 yr by Anthony123
More detail

It's projector headlights

They have a mechanical shutter mechanism that moves between Main and Dip beam. I don't know how it works but perhaps that is sticking and squealing. Do both lights move between Main and Dip okay?

Well dipped and fill work fine. One thing I've noticed was that the left light beam was always slightly lower on the wall about an inch. Il have a look tomorrow and see if I can figure it out. Very interesting about the shutter. Thanks. I will post if I find anything wrong with it. 

Hiya Guys is there any update on how to fix the issue as i have the same problem?

On 16/02/2023 at 22:43, Anthony123 said:

Well dipped and fill work fine. One thing I've noticed was that the left light beam was always slightly lower on the wall about an inch. Il have a look tomorrow and see if I can figure it out. Very interesting about the shutter. Thanks. I will post if I find anything wrong with it.