had my 2001 octavia ambiente for about six weeks now and really like it, i have noticed that when warm it takes a few seconds of cranking for it to fire up, its fine when cold starting straight away, i think the thermostat is kaput as it takes ages to get up to central mark on temp gauge, would this have any bearing on the slow start issue,? its a 1.9 tdi engine, and is it a big job to change the thermostat? had a look around and can't find its location but somebody told me its behind the alternator.

Try changing the temp sensor, costs about £13 delivered from Joliry (I think that's what its called) it seemed to have cured mine but then some plonked ran into it! It's a common problem.

My advice is get a genuine VAG CTS. Aftermarket CTS's are notorious for failing. Could be the thermostat is stuck open though, but I'd still do the CTS as well.

ok thanks for that i will try a temp sensor.

I have the same problem. It is to do with the engine needing to get to 240rpm before it will start when the coolant is above a certain temp. If you unplug the temp sensor (which then disables the glow plug circuit) and start it when the engine is warm you'll find it fires straight away. The problem seems to stem from a weak battery combined with a slightly worn starter motor, dirty earths etc and then the problem gets worse as the starter starts to crank more, wearing even more.

Try googling TDI hot start problem, it's very common. There's a wiring mod called the Hamman mod which can overcome this problem. Otherwise it's recommended you get a new battery and starter motor, which is a bit expensive.