I noticed for the first time last week the engine pre-heat light come on when I started then engine from cold (about 3 deg C outside).

This morning it was even colder (1.5 deg C) and no preheat came on ? Is this normal ?

To be honest I've never given it a 2nd thought - being a bit of a diesel newbie - but surely the engine should require preheat on most cold starts?

 

In the old diesel day it took up to half a minute or even more to preheat.
On mine i didn't notice it before.
Now when temperatures are dropping i too noticed the preheat simbol coming up for a second or so.

 

I've noticed the coil symbol, but nothing more. Doesn't seem to affect things, or delay the engine firing up.

I have noticed that the diesel engine takes longer to warm up than petrol. A colleague in Finland explained that diesel cars there put out so little waste heat, that there's not enough to warm the inside of the car. So they have to install secondary heaters. Interesting!

I've also heard about "winter diesel". But perhaps that's an old product. Only seems to be the one diesel, which we use all year round.

 

How often do you see the coil symbol ? I have only ever seen it once.

 

Noticed it a few times. Don't pay any attention to it, so maybe it's most times. Maybe it was just the once or twice.

 

Does the pre-heat not come on when you open the door rather than the ignition key?

Just a thought.... saves time in the long run

 

It's the same diesel fuel that is used in home heating systems (only colour difference). The winter diesel I believe has additivies to stop the fuel from freezing when in outside storage tanks for home purposes.

Re the glow plug symbol, because diesels are compression ignition systems, there is no spark plug to ignite the mixture. The glow plug heats the cylinders to get the fuel ignited first after which the heat generated keeps it going. With newer diesels, the glow plus is almost instantaneous in milder climates.

To minimise waiting time to heat the cylinder, VW, on some cars, started the glow plugs when the driver opened the car door. So by the time the drivers ass hit the seat, the diesel engine was ready to fire up. Thought that was clever.

 

My dealer told me that I should disregard the icon and proceed immly with starting up
irrespective of weather conditions. So far had no problems. That's my second winter.

 

Your dealer is right, you can do that. BMW Diesel enbgines are so damn good that you don't really need the pre-heat.

 

Thanks guys that puts my mind to rest !

I'm in the dealers next week for a few troubles - I can knock this one off of my list.