For several months my Ford Smax 1.9 tdci 08 plate will not start first time. It has been in 4 garages, been rigged up to diagnostic machines, had its glow plugs replaced, battery changed and still not one garage can tell what's wrong or why its doing this. Its groundhog day. The day starts.... Starts by second attempt, get to destination then back in car 5 to 30 attempt to start, it gets worse as day goes on and takes more attempts to start. It sounds like it wants to start but doesn't fire up straight away. The time leaving it between trips or taking it on a long run has no effect on its starting. This doesn't help when doing the school run and I'm now leaving my engine running when doing the school run because I know it will fail to start. I've had the RAC out and they didn't know what was wrong with it either. Costing me a small fortune to find out nothing.

have you done any scans on the car for error codes?

I would say your looking at an issue with the car cant heat the engine properly.

Try sitting in the car, turn the key over for 10 seconds to position 2, then back to 0, then repeat 3 times.

This will at least give the car the best chance of heating up to see if this is the problem. My car is slow to start in the cold, and I am about to get the glowies changed.

we do this every time we start the car. It makes no difference. the problem started mid Aug, so weather hot or cold makes no difference. We have had the glow plugs change because we thought that was the issue. Sadly it wasn't. Thanks for you help.

the only other thing it could be is not pretty...

your DMF could be on its way out, disintegrating and the shards could be in the starter motor causing the car to struggle to start.

It is EXTREMELY common on the TDCi engines.

It is caused by the DMF. Due to the cost of replacement most owners just live with it.

get the crank sensor removed and check it for iron filings blocking the signal, as this is a common fault if the DMF is failing, and will cause a difficult start.