Sprinter making whining noise when accelerating and decelerating.

[ringway]

Evenin' all.

My 2001 313cdi sprinter makes a whining noise when accelerating and decelerating - sounds a bit like and old fashioned police siren.

Just replaced the viscous fan so all quiet now apart from the whining noise.

Any ideas?

Many Thanks.

Paul.

 

[Sp!ke]

Is it sort of a whistle noise?

 

[ringway]

Is it sort of a whistle noise?

No, not like the sort of whistle you'd hear from say, a split hose.

It's a whining noise that follows the rev pitch like when a radio has a bad earth, but this noise is thicker and mechanical.

 

[Sp!ke]

Spend £8 on a mechanics stethoscope like I did.

Pinpointed my noise in minutes.

 

[ringway]

Spend £8 on a mechanics stethoscope like I did.

Pinpointed my noise in minutes.

Never used one before but I'm sure it is worth getting one.

 

[cplnoonoo]

Does it do it when revving in neutral whilst stationary or only when in motion?

 

[ringway]

Does it do it when revving in neutral whilst stationary or only when in motion?

Yes, the noise can be heard when revving the engine whilst in neutral, although not as pronounced as when driving.

Thanks,

Paul.

 

[corned]

Wild guess dept: Water pump bearing heading south?

Or alternator bearing?

 

[BlackC55]

It could also be a turbo on the way out. Remove the hose (very easy to get to) and to see if there is any play.

 

[ringway]

It could also be a turbo on the way out. Remove the hose (very easy to get to) and to see if there is any play.

Thanks Olly.

There is around 1.5mm play in the turbine at the front. Is this normal?

Cheers,

Paul.

 

[BlackC55]

1.5 I would say is a little excessive. Run the engine and rev it. Does the noise come from there?

 

[lynall]

So long as rotor vanes are not touching the turbo casing i would say its okay.
Remove fan belt and start engine to check for noise.



Lynall

 

[ringway]

Or alternator bearing?

Give that man a prize.

I think the alternator is on the way out.

In neutral, held revs at 2000rpm and turned on lights, wipers and heater blower and the whining noise changed.


If this is the case do I use MB alternator or does anyone know of another brand that is up to the job?

TIA.

 

[bennesspipers]

Bosch ?

 

[BaldGuy]

Leave the wife at home!!

 

[bennesspipers]

If you haven't got a mechanics stethoscope, just use anything like a long screwdriver or 18" of brush shaft, one end to the part you suspect,other end to your ear (Carefully avoiding moving parts of course) I'v used this method for years.

 

[ringway]

It is indeed the alternator.

Around £330 + Vat from MB (£30 exchange).

Does anyone know of a compatible alternative make that is not so expensive?

Sprinter 313CDI 2148cc 2001 X Reg.

TIA.

Paul.

 

[wemorgan]

Would you be OK with a second-hand part?
Something like this seems a good idea. Not tried them myself though.

Mercedes Parts - Buy Mercedes Parts from The Parts Gateway

 

[jaymanek]

check with Euro Car Parts.. you could get an OEM make much cheaper.

 

[ringway]

I fitted a new alternator and serpentine belt this weekend and the noise still remains.


So maybe water pump or one of the other pulleys? I hope it's not the turbo.


I've booked in the job with myself for next weekend.