Strange whining noise - possible alternator or AC compressor?

[JackBvmb]

JackCLK280New Member
Hi, my car has started making a weird noise. It does it almost everytime I start the car. It lasts for around 30 seconds and stops. Then reappears every 3-4 minutes. I don't notice it when driving, just when idling.

I'm really hoping it's just a pulley???

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

Thanks,

Jack

On another note, I have the option to buy a 5.5 CLK500. Are they worth it? It's a cabriolet, 85,000 and £7000. Only part service history.

 

[JackBvmb]

Anyone? Feeling pretty lonely in here.

 

[Oldlae]

It is hopefully the idler pulley bearing.
Tony

 

[pillow]

It would be useful to open the bonnet and record. Try to identify the area the sound is loudest and you can get a good idea of what it might be.

Just from that it sounds a lot like the radiator fan or similar.

Does it happen on a cold start?

 

[unimog]

I have something similar on my C350, going to replace belt and pulleys as mine is constant for a few minutes after start up, but as the steering feels a bit more ‘wooden’ than usual I’m suspecting the PAS pump is on they way out...

 

[JackBvmb]

Thanks for the reply, I'll get a recording under the bonnet later, after work and post it. I had a listen this morning and it's coming from the front of the engine, behind the radiator and fan.
Sorry, I'm not very mechanically minded.

It does it from cold always and almost always from warm.
The noise seems to have returned to 'normal' again - as in the noise from the original video.

Thanks

It would be useful to open the bonnet and record. Try to identify the area the sound is loudest and you can get a good idea of what it might be.

Just from that it sounds a lot like the radiator fan or similar.

Does it happen on a cold start?

 

[JackBvmb]

I have something similar on my C350, going to replace belt and pulleys as mine is constant for a few minutes after start up, but as the steering feels a bit more ‘wooden’ than usual I’m suspecting the PAS pump is on they way out...

Thanks for the reply. Hopefully it's not your pump. They're pricey. I'm going to try to do the pulley myself... hopefully it's not too difficult.

 

[Larkone]

There are plenty of youtube videos on how to take the tension off the serpentine belt and then you can spin the pulleys to check which one is wearing.

 

[steve333]

If it is a pulley I would replace them all and serpentine belt-usually recommended around 80-100k miles.

 

[chrisk2010]

I haven't listened to your vid but the secondary air pump is a noisy little so and so and makes horrible whining noise when starting the car and when idling after a journey.

I have read it's an inherent problem to the pump but not detrimental.

You tube vid here

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

 

[JackBvmb]

If it is a pulley I would replace them all and serpentine belt-usually recommended around 80-100k miles.

Hi,

What do you mean when you say replace them all?

 

[steve333]

Pulley(s),belt.

 

[wongl]

Is the whining noise related to the air con being on or off?

 

[JackBvmb]

Is the whining noise related to the air con being on or off?

No, it makes no difference.

 

[slade1]

Agree with steve333, change the lot as precaution The idler pulley let go on my CLK M272 motor. the shredded belt wrapped it's self round the crankshaft between block and pulley causing more problems. You will be surprised how small the bearing is on idler.
Use only OEM parts

 

[JackBvmb]

Thanks all for your thoughts, I think I'm going to have to take it to a garage. So many avenues you take and I domt want to piss money up the wall replacing parts that are potentially ok.

Thanks again!

 

[JackBvmb]

Sorry. Me again. I'm like a boomerang, keep coming back.

I think I have found the noise.

Does anyone know what this is and is it an easy fix/diy job?

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

Thanks,

Jack

 

[pillow]

Sorry. Me again. I'm like a boomerang, keep coming back.

I think I have found the noise.

Does anyone know what this is and is it an easy fix/diy job?

To view this content we will need your consent to set third party cookies.
For more detailed information, see our cookies page.

Accept third party cookies

Thanks,

Jack

Secondary air injection pump.

I would say it is one of the more straightforward DIYs you could do.

 

[JackBvmb]

Secondary air injection pump.

I would say it is one of the more straightforward DIYs you could do.

Hi,is it a fixable or a replace?

 

[chrisk2010]

Hi,is it a fixable or a replace?

Have a look at the vid i attached in post #10 he strips one down Jack.

It may be fixable but much easier to replace.

They are noisy things though they work on start up to blow air into the injection to help get the Cat converters going from from cold.

If anything goes wrong they usually throw a code P014 .... something i can't remember off the top of my head.

Mine makes the same noise but hasn't thrown codes up and is excellent on the emission from the car come MOT time.

I'll swap it out at some point but with no urgency do note though there is a relay that controls it i think (don't ask me which one) if it's on all the time it could be this.

In the summer months you may not notice it as much because the Cats warm up faster.