Hi,

I have a 2001 Mk3 Mondeo petrol that has done nearly 70k. It is in great nick but..... about a week ago I have noticed a rattling coming from the engine ONLY at idle and ONLY when the engine is hot (not mildly warm, but hot). The rattling is irregular and sounds kind of like you are shaking a plastic box with a coin in it. The rattle doesn't seem to be contributing any vibrations. As soon as you gently press the accelerator the rattlings stops.

On closer inspection with the bonnet up, it sounds like it is coming from the belt area (to the left of the engine). These symptoms suggest a possible belt tensioner on it's way out or the more worrying scenario of the inlet manifold butterfly flaps breaking loose!!

I took the car to a mechanic yesterday and suggested these two possible scenarios. I got the car back today. The mechanic said there was excessive play on the tensioner so he fitted a new one. I was relieved and very thankful........only to come home just now and hear exactly the same rattle as before. The problem is not fixed and now I am very worried it could be the manifold flaps, even though I have spent money on getting the tensioner replaced!

So I have put it to this forum. I have tried to be as detailed as possible with the symptoms. Do these symptoms present themselves as a manifold flap problem in people's experience, or could it be something else?

I commute 120 miles daily on a round trip to and from work. Is it wise to continue this until I can get the car booked in for a weekend?

Thanks in advance