A `whistle' When I Changed Gear In My 06 2.2 L Titanium X Tdci

[davisfrank]

I have recently changed to 2.0L Titanium Auto to protect my worn out left knee. Recently on my 06 2.2 Titanium X Tdci I noticed what I can only describe as a `whistle sound' when changing gear, 1st to 2nd and 2nd to 3rd, it was quite obvious and louder if I changed on a fairly high rev. The sound came with the `over run' between gears and I assumed it was an idler or bearing in the gearbox preparing to fail. I am not mechanically minded but in my car which I had had from new, and was at 58,000 miles, I knew every squeak and rumble intimately. Although I have to say I have had many Mondeos and loved every one of them, so squeaks and rumbles were few and far between.

I arranged to have my local Dagenham Motors look into it after they expressed puzzlement over the phone. Before I could get it to them the rear box of my silencer fell off, jammed and I had to get the RAC to remove it. During the interim I still had the whistle when driving and eventually took the car into the garage to replace the box and listen to the `whistle'.

The box was replaced and when the car was returned they told me they could not detect a `whistle' and sure enough neither could I. It seems that when my rear box was preparing to fall off I developed a warning `whistle' when changing gears? I don't know what caused it but if you should hear an unusual `whistling' sound when changing gears get the rear exhaust box checked before it falls off, like mine did, at 40 mph.

[merckx]

You always have excess air with a turbo engine when you change gear as the turbo is still turning but the engine isn't requiring the air for combustion. I'm not sure how the mondeo system works but many turbo cars have a blow off valve (bov) which you'll get a slight whistle from when you're changing gear and taking your foot off the accelerator,

I'm sure the change in flow rate through the leaking exhaust will have caused the whistle to become louder and therefore audible with it obviously having a turbo which is very much dependent on having a fully functioning exhaust.

On my 2.2 TDCI the whistle started a couple of weeks ago, the back box broke loose this morning and the whistle is now much louder. Fortunately I was only doing 30mph, heard a little thump and then a loud one as the box pivoted under the car lifting it up making me think I ran over something or there was a problem with a wheel. Just need to decide where to get an exhaust from now.