I was driving in an unhurried manner in traffic (sub 30mph) the other day when, as I recall, I changed up from second to third and was treated to the most awful noise from the engine. It was very loud and very difficult to describe! Rather akin to someone hurling an enormous number of pots and pans continuously down a metallic refuse shute!

Interested, I did not immediately drop a gear, but applied the accelerator gently to see what would happen. I found that I had lost the ability to drive forward ... it felt as though I had not engaged third properly.

The BMW behind me had dropped back the moment the noise happened, which may give an indication of how loud it was! The moment he realised I had lost forward momentum he gently eased past me.

Letting him pass I dropped to second and the noise stopped instantly. Thereafter I have tried to replicate it, but cannot. The car went on to drive normally in all gears.

I recalled I had heard the same noise once before when passing a demolition site in our local town a few days ago ... on that occasion I had thought it must have been noise from the site!

Took the car into the dealer ... they have had no notice of a problem like this. A mechanic took the car out, but couldn't replicate the problem - he then asked me to drive him round for 15 minutes but we had no joy either. I asked him if he had any worries about my driving, to which I got, "Actually you are driving extremely well", which was comforting! The car was put on a ramp, but nothing unusual found, so the dealer drew a complete blank.

Dealer has notified Ford, but I wondered if anyone here had experienced this problem and knew the cause. Car was bought (new) in April this year and has circa 8,500 miles on the clock. It is a manual 1.5TDCI.

Perhaps the gear just didn't engage properly and the noise was the cogs clattering together?

alexp999, I have to agree with you. Sloppy driving on my part, I think! The car has driven many miles since the two incidents without another occurrence.

Sorry for the false alarm!

Not necessarily your fault. If you happen to go to engage the gear and the teeth on the cogs line up perfectly at that moment then they won't mesh and will effectively bounce back off each other, which leaves the car half out of gear and you'll hear the cogs clattering.

The B5 box is notorious for doing this in reverse gear almost every time. But any gearbox has the potential, it is just very unlikely that the cog teeth perfectly line up at the point of engaging the gear.

The syncromesh helps but can only speed match and not line up the cogs.

The only influence the driver can have is feeling that the gearstick hasn't gone all the way in to position.