odd groaning noise on A150 (W169)

[calum]

Odd. Our A150 (new shape W169) has just developed an intermittent noise.

Sounds a bit like a pump groaning, or something. It does not change with rpm, nor braking, nor with speed, it occurs when moving and at rest. Once it occurs, it will continue until the ignition is turned off. If the car is then re-started, it will be some minutes before the noise returns.

It's quite intermittent; won't happen at all on some journeys; on others it starts within a mile of home, and then the only thing that will stop it is ignition off.

It's quite loud, and doesn't seem to get louder when the window is opened, suggesting it's occurring near the passenger compartment. It's not family members complaining about my driving, either

Being neither rpm nor speed related, and the fact that it continues even when the car is brought to a halt, without changing pitch on any of these actions, seems to rule out almost everything

My last guess is perhaps power steering pump, although turning the steering wheel has no effect on the noise.

Any suggestions or advice very gratefully received.

[apols to mods: this may be in the wrong forum, but it's not obviously right for the others, either]

 

[Robbo]

It wont be the power steering pump, the W169 has electric power steering assistance.

Get it down to the dealers and let them worry about it, its still under warranty!

 

[Dieselman]

It wont be the power steering pump, the W169 has electric power steering assistance.

It could be because it's electro-hydraulic so still has a pump. In addition it could be the air conditioning because isn't this now electrical also?

 

[calum]

It wont be the power steering pump, the W169 has electric power steering assistance.

Get it down to the dealers and let them worry about it, its still under warranty!

thanks; yes, I will book it in. However, previous experience there has been somewhat poor, so it would be nice to have an idea ahead of time.

Last time there, we had two issues: a safety bulletin recall thing, and the driver's window one-touch close stopped working (but one-touch opening working). They said they wouldn't do the safety thing, wait until next service - this two weeks after its first service, on a low mileage car - and the window they said was "supposed to be like that". Despite the fact that it's been working since the car was delivered. sigh.

 

[calum]

It could be because it's electro-hydraulic so still has a pump. In addition it could be the air conditioning because isn't this now electrical also?

thanks; I did try turning off the A/C on the panel, but it made no difference to the noise. On my E350, turning off A/C (i.e. via EC button) you could hear the compressor stop and start.

 

[Robbo]

It could be because it's electro-hydraulic so still has a pump.

Oh, in that case I guess it could be that then.

 

[ddentrec]

thanks; yes, I will book it in. However, previous experience there has been somewhat poor, so it would be nice to have an idea ahead of time.

Last time there, we had two issues: a safety bulletin recall thing, and the driver's window one-touch close stopped working (but one-touch opening working). They said they wouldn't do the safety thing, wait until next service - this two weeks after its first service, on a low mileage car - and the window they said was "supposed to be like that". Despite the fact that it's been working since the car was delivered. sigh.

This is to be expected with the Mercedes marque: you bought into the brand, and they now have your money.

Some dealers are good. Most are not. You have to fight to get what you want: write to DCUK and complain that YOU are the customer and you want things fixed. When I complained about the rusty and supposedly aluminised exhaust on my 30-month old C-Class (mounting lugs corroded through - about 3 more months till it fell off) dealer said 'they are all like that - stop whining - and it is not covered under warranty' I wrote to DCUK and hey presto I got a new exhaust.

Dealers work on the principle that 90% of customers will not push back when they are fed nonsense - and in most cases that is what happens. Good luck.

P.S. I see yopu are in the Cambridge area -avoid Robinsons in my view - worst of the bunch for crap excuses. Go to Sytner in Bedford: far better service, and no stupid daily charge for the courtesy car unlike Robinsons.

 

[calum]

thanks much for those comments. Yes, you guessed the dealer.

We've just had them on the phone: the noise is coming from *inside* the tank, but the person I spoke to had no idea what might be causing it. It's a shame when the service advisers don't know, and aren't told, the tech details. It's bound to be a pump, I suppose?

Anyway, they don't have tanks in stock, and they've now left it late enough that they can't get one in for tomorrow, so we have to go and get it, and book it in next week and, yes, pay another 10 quid (per day) for a loan car. That and we only even got the loan car at short notice when my wife told them we have a baby and not having a car would be a problem. Initially it was going to be some weeks to wait for a car (I've had this before).

As it is, we got a very nice 06 C220, leather, etc.

 

[calum]

P.S. I see yopu are in the Cambridge area -avoid Robinsons in my view - worst of the bunch for crap excuses. Go to Sytner in Bedford: far better service

Bedford? That seems a bit of a trek, to drop the car off and pickup etc? Or do they bring out a loaner to you? That would be nice.

 

[Birdman]

I've had better luck with Robinson's Bury who have given sensible answers to my questions and solved technical problems efficiently. But if I have to start paying for a loan car (never had to yet) I shall use their delivery service instead. Unless they charge for that too!

 

[calum]

yup, my friend in Newmarket has had positive experiences with them, too.

 

[Birdman]

I had dealings with Cambridge just once, when considering trading in my Porsche. They were more interested in what watch I was wearing than answering my questions. The only time that happened before was in a Chinese restaurant. In China.

On the follow-up call they asked what I'd bought instead. When I told them, the only question they asked was, 'how much?'

That sort of summed them up, I thought.

 

[ddentrec]

Bedford? That seems a bit of a trek, to drop the car off and pickup etc? Or do they bring out a loaner to you? That would be nice.

Hello again,

Takes me 20 mins to drive to Bedford along the new A421 bypass. They will not collect the car or drop off a loaner - no bother to me.

Funny thing is that Sytner Beford have told me they have 11 other ex-MB Cambridge customers who have defected.

Something definately wrong at the Cambridge branch.

One other thing: MB Cambridge took on average 3.5 dealer visits to fix a problem; MB Bedford take 2.1 visits. Another reason I swapped dealers. Crude statistics, but expect to visit them again. And again.

 

[calum]

interesting, thanks.

update on original problem: fuel tank swapped out, groaning noise has now gone.

Coincidentally - or not - the main key fob stopped working the day after we got it back from them. The spare works fine. Tested the battery in the main one, seems fine. Odd.