Hi,

This is my first post using this forum as I am a new Audi owner as of last week.

The car is a 2005 A4 2.5TDI Cabriolet, 74000 miles, 6 speed, front wheel drive.

I am having problems when it comes to starting the car from cold which I have read about and have tried most things so far. When turning the key it takes longer than usual (about 6-7 seconds) to start, followed by a cloud of smoke which Im assuming is excess fuel. It starts fine when warm.

I have so far changed glow plugs, fuel filter, camshaft timing sensor, coolant temp sensor with no results. The coolant temp sensor was suggested because if I unplug the sensor the glow plug light stays on longer and the car starts perfectly! Had the car plugged into diagnostic equipment with no fault codes.

Starting to lose hope now so any help would be appreciated greatly. Next I was thinking glow plug timing relay but I am just guessing now.

Thanks,

Phil