I have read all of the comments about diesel starting problems, but mine still persists! I have a 1999 1.9 diesel estate. I changed the sensor with the green ring with a brand new one (about

Mr Music.

Thanks to this forum I was able to COMPLETELY solve the exact same problem which You are experiencing.

The answer for me was Part No: 6UO919501 B.

Temp Sender with a BLUE band.

This will leap off your Skoda Dealers Parts Fiche as being for a 96 on 1.3 Petrol but Ignore the crying and fit it.

The difference was immediate and now the Glow Plug light comes on for a couple of seconds and Up she flies.....

it might be a problem associated with the little black box that controls the glow plugs/relay

I promised I would report back, and I am delighted to have followed the advice to fit the sensor from the petrol 1.3 engine, as advised by Alek Smart in the previous posting but one. However, the one I found on eBay had a yellow, not a blue band. No matter, I fitted it and ever since the warm start problem has completely disappeared. I did notice that the temperature gauge was reading nearly 10 degrees higher, but that is only a false reading sent by the sensor. The fuel consumption remains the same. The only other thing I've noticed is that the car always appeared to make a sound very similar to "pinking" on older petrol engines when the ignition was too far retarded (or advanced, can't remember which now). It still does that, but slightly more often. What the heck!

So, many thanks to Alek Smart, a smart man indeed!

By the way, the sensor cost just

you need a yellow temp sensor no other colour. blue or green is wrong for a diesel.