Evening all.

I have 2009 TD4 with a squeaking noise coming from the top right of the engine. I thought it may be an injector so pulled the power to the injectors 1 by 1, the squeak still remained. It is very constant and sounds almost electrical rather than mechanical as it pulses. It goes once the revs rise from idle even by just 100rpm. Any ideas before I take it to a garage.

Thanks

Simon

Could be the vacuum pump?...

Thanks Alex, would you be able to point me to the vacuum pump as this does sound like the culprit.

Aux belt tensioner

It's the other side of the enginw so definitely not Aux belt tensioner. Standing on front of the car the noise is coming from the top right hand side. It only does it when warm. Cheers

Just an update on this. It seems to only make the noise after a start stop cycle, possibly related to this. There must be something different when the car goes in to start stop mode, can't fathom out what though.

Could be the throttle body as that can make a noise similar to a squeak?

Thanks, it squeaks whilst engine is running so def not Throttle body. Looking at where the noise is coming from it is either the HP fuel pump or vacuum pump. Plenty of threads on failed fuel pumps but none on failed vacuum pumps so the cynic in me thinks fuel pump.

If the squeaking is with a frequency about the same as the engine diesel knock, then it's the vacuum pump...
I also have a noise in that area, but it's more like a ticking noise than a squeaking.
In extremis, you can dismantle the vacuum pump - only 3 bolts - and see if the squeaking stops.