weird engine noise

[zulfi]

I have a 2003 E320 mercedes. For the last month there has been an intermittent noise coming from the engine. It occurs when the engine has been switched off for some time and the car is stationary. The noise is almost like an electrical beeping but I now think it is a more squealing noise- like something is being forced through under high pressure. I have located it to the right side of the engine - near the power steering pump (so the dealer tells me). The dealer has no idea what it could be (its a good job I managed to record it on tape otherwise I'm sure they wouldn't have believed me). Nobody has any idea what it is -especially as the engine is switched off and the car is not moving. Can anyone shed some light on the matter? I would be very grateful for some advice.

 

[Keith D]

Engine Noise

Check that the hampster is still in it's cage.

 

[panason1c]

There is a cooling fan fitted in the 'electronics' box located under the bonnet,(similar function to the fan in home computors) the bearings on these fans can sometime go dry and make the 'squealing' sound that you describe. Maybe worth checking out?

 

[guydewdney]

coolant going through the cap of the radiator? try loosening the cap when the engine is off and still warm - NOT hot - you may well scald yourself... does the noise stop?

panasonic - he said engine OFF.. would the fan be running after its switched off?

 

[panason1c]

Guy,
I dont know if the fan i refered to would still run after switching the engine off...i just pondered the possibility that it may 'time out' after stopping the engine to continue cooling the electronics....just a long shot. (-:

Having said all that, i think you may have the correct answer regarding the rad' cap.

 

[TheJim]

Long shot, but it could be that the power steering pump is on its way out. You can get strange beep type sounds when fluid is getting past the seals. My Dad had a Lancia Thema that did it sometimes when it was parked on a high kerb, the extra weight on one of the front wheels was enough to cause it to make almost a chirruping noise like a small bird. Took us a long time to hunt it down using a length of rubber hose as a stethoscope.
Good luck.

 

[zulfi]

Thanks for the suggestions. Its not the radiator cap as I have heard the noise after the engine has been off for over an hour and is cold. It's definitely not a fan of any sort but it does seem to be coming from the power steering pump. Thanks for the suggestions. Any more suggestions - the dealer has never heard of such a noise before (I had recorded it on my mobile). He also said that if he changed the power steering pump then it would no longer be covered on the merc warranty. Is that true? The power steering suggestion may be the correct one as I've noticed that most of the time it happens when the car is on an incline or parked on the kerb.

 

[SLinKyjoe]

Thanks for the suggestions. Its not the radiator cap as I have heard the noise after the engine has been off for over an hour and is cold. It's definitely not a fan of any sort but it does seem to be coming from the power steering pump. Thanks for the suggestions. Any more suggestions - the dealer has never heard of such a noise before (I had recorded it on my mobile). He also said that if he changed the power steering pump then it would no longer be covered on the merc warranty. Is that true? The power steering suggestion may be the correct one as I've noticed that most of the time it happens when the car is on an incline or parked on the kerb.

a new item fitted under warranty will be covered by the existing warranty for its remaining term. the part itself will also come with some gauruntee from its manufacturer...so if it was fitted with a month of your warranty left then the part could reasonably be expected to last at least a year or more without trouble. so they are not giving correct advice there...and if it was correct then they would change all the parts on your car at the first service for free and take it straight out of warrenty.

get him to confirm all what he said in writing if it comes to it..bet he wont

you have to make sure that you are driving the vehicle in the manner it was built...by that i mean if you charge up and down over the kerbs they they could argue that isnt wasnt built for that and you have caused the problem by operating the vehicle outside its design. The warranty should cover parts that develp a defect during normal usage over a time they would expect it to last without developing a fault.

 

[zulfi]

Thanks for the advice. The car has only done 13000 miles and has one year of warranty left. I've only parked it on the kerb once- not out of choice. Would you expect the power steering pump to go after 2 years? I think I'll get him to change the pump. If I hear the noise again then I'll get my stethoscope on to it to see exactly where its coming from. Cheers.

 

[TheJim]

I have an old merc so I don't ever go anywhere near a dealer. Boy am I glad.
Hope it all pans out OK.

 

[jberks]

I suspect that he meant that if the pump was not the cause, the warranty wouldn't pay out and you'd end up footing the bill. Daft question, but where is the alarm sounder situated. - I had an new audi A3 alarm that used to beep randomly when parked up. Sound came from the rear bumper on that one.

 

[zulfi]

yes I think your right about the warranty. I used to have an alarm that beeped (VW Golf). It's definitely not that. This squealing noise has no regularity about it - the noise and frequency can be different minute to minute. I think thanks to you guys that I have enough evidence as to what the problem is. Question is if the noise only occurs once every 2 weeks whether its worth changing the power steering pump.