Hi All

Wondering if any of you out there can help identify the possible cause with a noise I get when starting my 2006 Focus 1.6 TDCI.

This noise has happened a few times now, doesn't happen every time the car starts, in fact the last time it happened must have been over a month ago. But this morning I started the car up, which was fine, but for the first 20 - 30 seconds of running I was getting an odd metallic rattling, jangling type sound coming from the engine bay (driver side I think). Its best described a someone rattling a small piece of metal inside a cup, glass or tin can. After 30 seconds or so, the sound went away, the car drove fine, with no other noticeable noises happening.

Any ideas on possible causes for this would be greatly appreciated.

Many thanks in advance.

I am no expert in this area, but it could be the Dual Mass Flywheel. Are you feeling vibration too? I had this go in another car I had (VW) which was similar to what you describe. are you lacking power? Need to rule out the turbo of course!

On 13/12/2016 at 9:55 PM, Monster Green said:

I am no expert in this area, but it could be the Dual Mass Flywheel. Are you feeling vibration too? I had this go in another car I had (VW) which was similar to what you describe. are you lacking power? Need to rule out the turbo of course!

Thanks for the reply Monster, really appreciate your comments.

I haven't noticed a lack of power, but the noise seems to be coming from the drivers side of the engine, more towards the top I'd say. I haven't noticed any vibration while driving either. I have had a number of people say DMF failure is imminent, but I've also had a few tell me that it could be the small timing chain that links both camshaft cogs has become slack, or the tensioner for this chain has started to fail.

Just wondering if you can remember, or know where the noise from your DMF failure was coming from when it went?

Got an update on this for you. Just so you know the car has done 113,000 miles, and I'm pretty sure it has the orginal turbo.

I'm pretty sure the rattling sound isn't anything to do with the DMF. I drove the car to our local petrol station, and whilst waiting to fill up the car was making the rattling sound. I put the clutch in and the car still made the rattling sound. When I got it back home the noise had stopped. The noise seems to be more noticeable while idling, and not when driving or under load. It doesn't lack any power, still pulls really well, so I'm not convinced its the turbo. I did check the the spindle in the turbo when I took the air intake pipes off to do an air filter changed not long ago, and there was no movement in the spindle, and it spun smoothly and freely when I turned it.

Before I went out this morning, I took the auxiliary drive belt off and started the car from cold, and no noise occurred at all. For its first MOT of me owning it, I let my mechanic mate give it a pre MOT, and he noticed that there seemed to be dust coming from the crankshaft pulley, didn't know if this was significant, but its been like it for many miles now and not caused any problems.

The sound to me does seem like a metallic rattling sound that is in time with engine revs.

Any other ideas would be greatly appreciated

Just thought I'd update this discussion with what I have discovered.

I let my mechanic mate listen to the sound and he said straight away that it sounded like the auxiliary drive belt tensioner was failing. I put a new one on a couple of days ago and I have not had the rattling sound happen again on cold start up. S it seems like this was the issue and I'm well happy that the fix was a £30 part and 20 minutes of my time, wish all car problems were that cheap and easy to fix!!