4.2TDI Engine Noise
 

I noticed today when I left the office I had a noise, sounded like it was in time with the engine or wheel.

So got home and opened the window and heard it again. Put the car in neutral while moving forward, noise spins up, so its engine related.

So I took the cover off and recorded this.

Engine pulls well, no warnings. It was serviced 2 weeks ago, so unless its related to the service, not sure.

Thoughts?

Googling 4.2TDI issues doesnt raise much .... these engines are normally bomb proof?

https://www.youtube.com/watch?v=ZoxpQNXDl-s

I took a vid as I arrived at work this morning. The car is parked from around 2 mins in and you can hear the sound whilst revving the engine.

https://youtu.be/quuK2GqjQco?t=2m10s

If I had to guess, Id say something like a timing chain tensioner. Does anyone know if this is a failure item ....

Google gives very little about issues with these motors, so not sure what it might be.

Definitely sounds off but so hard to pinpoint.

On the second vid it sounds a little delayed, almost like it could be something catching or rubbing on a belt or viscous fan.

And yes, bar a few DPF issues, the 4.2 Tdi is usually pretty bomb proof.....

Thanks.

Is the timing gear on the rear of the engine? The sound does seem to come from the rear but does not pin point to anything directly related to the RPM. It is also random but does increased as the revs increase.

Ill fiddle around over the weekend and see if I can track it down.

Thanks

Back of engine..possibly and hopefully vacuum pump.
Just guessing but worth a closer check?

https://www.youtube.com/watch?v=U2PZ4Xklx38
https://www.youtube.com/watch?v=yYlz9pDzfsY

Wow, thanks. The Beemer video sounds similar. Ill do some digging about vacuum pumps on the 4.2TDI.

I took a quick look. Arent all the 4.2 TDI engine ancillaries around the front of the engine? The sound 'seems' to come from the rear, so not sure.

I don't know but on other VAG V-engines, they come off one of the camshafts at the back (on longitudinally mounted engines) The pump is smallish and only one one side and has the air pipes for brakes etc.. coming off.

It seemed to respond more to some sort of pressure. The closest I've ever heard, was a catalytic converter had broken up and made a similar sort of noise. Doesn't really sound like a pulley or tensioner as it would sound more consistent and be in tune with the RPM. These engines are pretty complex so it's going to be either something major, or something minor that's tricky to access.