Presuming this has been answered many times but unable to find what I am looking for so hoping someone can point me in the right direction.

I have recently purchased a 2009 Mondeo estate, its a 1.8TDCI Titanium. Whenever the engine is revved I get a constant whine which seems to match the revs (louder as revved, high to low sound during engine braking).

Can be heard from drivers seat but when lifting the bonnet I can't hear it? Even during revs. Don't know if related but car appears to be giving an average of around 35-40mpg according to the digital readout on the dash on a pretty flat 60mph road.

Turbo boost seems to kick in but feels flat around 3000rpm.

I have read a few posts  in regards to boost pipes, turbo, EGR, alternator etc. Just wondering if anybody had experienced similar and where I should start. I noticed a small amount of oil where the intercooler pipe meets the EGR valve but fitting seems tight, can't see or feel any splits down the pipe as far as I can see or reach.

Thanks in advance.  

Just to make sure, are you hearing it inside the car with the radio on or off? Have you tried removing the radio fuse? 

Radio on or off its there. Driving to work today I notice that during engine braking, if I dip the clutch pedal it goes, release the clutch pedal and it's there again. Leaning towards possibly alternator on its way out.

Hi There

I have a 2010 Mondeo estate 1.8 tdci titanium with 125,000 miles on it and it has just started to do the same whine - I have narrowed the whine to either the alternator or auxiliary drive belt tensioner. I need to do a water pump on it real soon anyway (which is driven by the auxiliary belt) so I will find out here in the next week or two. Have also noticed an oil leak coming from the lower wet timing belt cover area so all in the one corner - Suppose with the age & mileage these things are starting to fail now - Will post my findings

If you dip the clutch and it goes away, I would expect that it is something to do with clutch, gearbox, and that side of things. if it was the alternator then surely disengaging the clutch would not change it (as alternator is driven at all times from the engine).

Booked in at garage on Tuesday so will post my findings. Would it possibly be the gearbox/clutch if it does it at standstill in neutral? 

1 hour ago, Aj Math said:

Booked in at garage on Tuesday so will post my findings. Would it possibly be the gearbox/clutch if it does it at standstill in neutral? 

If you dip the clutch you disconnect the clutch and gearbox from the engine. So if the whine continues after you have dipped the clutch then it sounds like it will be something from the engine side of it. If the whine stops, then it is probably something from the clutch / gearbox side.

Thanks for your help micro, would appear I have been looking in the wrong place. Researching the gearbox side I have found forums with similar issues and symptoms down to the likes of "input shafts, and bearings" etc which would make sense.