I am constantly amased that so many technicians still have not cottoned on to the fact that Glow plugs DO NOT contribute greatly to cold starting on Common Rail Diesel powered cars.

More often these days we are seeing a warning message, that draws attention to a glow device error. The reason I suppose is that their main function is to improve combustion during the warm up phase & therefore reduce emissions.

I do find it interesting that enough heat can be harnessed by compressing an intake charge at a temperature around zero degrees centigrade, to produce the heat required to ignite the injected diesel. It takes some comprehending doesn't it!

Regards

Dave