Hi people, this is my first post here so be gentle!

I have recently purchased a Mondeo 2.0 TDCI 115, 2006 with 73,000 miles on the clock. The car is brilliant, and the fuel economy is amazing! That aside however, at idle power there is a sound coming from the right hand side of the engine (can hear it equally well inside or outside of the vehicle), that 'purrs', but not in a nice way! It has the resonance frequency of a pigeon (!), and comes on once every one or two (sometimes three) seconds.

It is NOT a rattle, or a clunk, or anything like that, just a sound. In any other instance I'd blame a loose belt (or a wet belt), but normally this causes a constant tone, whereas this goes on and off every other second or so.

Very strange! Doesn't affect the drivability of the car, and it passed an MOT today with no problems, so it's got me thinking...

Anybody had similar encounters?

Cheers =)

its a very contraversial engine,we all gt the same problem lol,,ask any mondeo owner,,theirs a genius on this website called mintalkin,,thats his user name,,,get in touch with him ,,and he will guide you right!!!look him up!!

does the sound dissapear at a constant 1000 revs?

Sounds like the dreaded Aux belt Tensioner or Crankshaft Pulley....

I made the mistake of changing just the tensioner and belt as i was told it was that.... but it is the crankshaft pulley, probably advisable to change all 3.

I think every TDCi has the same prob on idle, i hear em when in supermarket car parks lol...

As soon as you increase revs to 850 + the noise dissapears....

Cheers for the replies everyone - yeah the noise isn't audible when driving, or like you said above idle RPM. But in saying that I don't know whether it's still there and just can't hear it because of the engine noise...?

Have done some other research before and the aux belt tensioner and crank pulley has been mentioned - my main concern is that it's not something about to severely screw up in the engine (it doesn't feel like this), I can bear with the noise on idle!

Also had an advisory slip from MOT about an oil leak - one of the seals is starting to wear, and wondered if it was related to this, but I doubt it.

Thanks again, and if anybody else has any advice please speak up!

Cheers =)

if you can stand the noise do not worry, if the belt starts bouncing around on tickover it time for the change, but it could be thousands of miles before it needs doing just keep an eye on it.when it does require doing you can buy a complete kit for the job.

http://www.fordpartsuk.com/shop/mondeo_20tdi__and_22tdi_duratorq_diesel_kit_1917.htm