Strange rotating machinery noise when switching off engine 1.9tdi

[Fryupdale]

My Superb has a 1.9tdi 130bhp engine and I have only had it a couple of months. It is an 05 reg and had £56k miles on the clock when I got it but now has 62k. It had been used for short journeys but now does mainly clear motorway and A road miles.

This morning I noticed that when switching the engine off at work, there was a noise of something in the engine ( a pump) slowing down rather noisily. Engine restarted fine but same noise again when I switched it off. Seemed like it was on the drivers side but it is difficult to tell. Any one any idea what it could be and what the end game will be?

Many thanks.

[jimbof]

Does it do it with the aircon on and off?  The AC compressor is on the driver's side at the bottom, with I believe a magnetic clutch to decouple it when the aircon is off (ECON mode).

[Fryupdale]

Thanks Jimbof. Of course what has happened now is that it has not performed the trick again! So everything is back to normal. I'll have to wait for it to kick off again. Hope it is a long time.....

[JP01]

Nothing to worry about.

 

I've heard it on mine several times, nothings gone wrong.

 

Air con, stuff.

 

I diagnosed it as the hamster taking a breath, from the tread wheel.

 

[rotodiesel]

Check the alternator freewheel pulley for freedom of movement when turned counter clockwise with the belt detached.

 

When you stop the engine, the alternator rotor should declutch and freewheel to a standstill. If your pulley is loose or broken it will make a noise when the engine is stopped.

 

These pulleys are very unreliable (there have been modifications) and can come apart when worn - often through the radiator. It's worth making a check, although noises are difficult to diagnose remotely.

 

rotodiesel.