Most peculiar engine noise from W202 C220CDi Sport

[420SE]

Just noticed this the other day when I parked up late at night. I was driving for about 30 minutes, at mixed speeds, mostly 30 to 40mph.

Exited car, locked doors and noticed a jet-like sound coming from somewhere in teh engine bay

It dies down after a while, about a minute and its deffo not the cooling fan - it is near to zero degrees outside and cold as anything!

It really does sound like there's a small jet wedged somewhere into the engine bay

Is this normal?

 

[420SE]

Anybody?

 

[Harley Man]

It may be a split in one of the turbo hoses, or the intercooler

 

[timskemp]

Fuel driven aux heater - they *are* a little jet engine and they sometimes keep running after engine shutdown - the one on my A class would also continue to plume vapour out of the exhaust pipe.

 

[C230kompressor]

its deffo not the cooling fan - it is near to zero degrees outside and cold as anything!

do you mean you have checked its not the fan? or because its cold you dont think its the fan?

 

[alexander patie]

timskemp has the right answer.

 

[fuzzer]

Yep , my w202 C220CDI made the same noise.

Its the aux heater , you can turn it off with the switch. On the 202 from memory its on the centre console and is visable. down by the gearleaver i think.

Because the diesel engine takes a wee bit to warm up , there is a small diesel powered water heater that warms up the coolant and warms up the car faster.

you can read about them here Webasto England

 

[420SE]

Many thanks for the input guys!

Is it advisable that the heater is off or should I leave it as is?

 

[fuzzer]

i just left them on in all my cars.

The only work below something like 8 degrees anyways , so the car only uses it when it needs it.

 

[420SE]

Many thanks, Fuzzer!