hawk521 wrote:
A couple of thoughts...
1. I have read that although the GP lamp goes out quickly, the GPs themselves continue to heat for another 15+/- seconds. Is this really true? Hard to know without more testing than I'm willing to do on a very cold morning - but if true - it might be useful to wait an extra 3-4 seconds past the extinquishing of the GP lamp.
Hawk521
If not it would be the only diesel car in the world without the after-heat feature. This is used to keep the cylinder temperatures up while the engine has just started. Normally when cold starting a diesel engine the glow plugs heat up the chamber enough to let the compression detonate the diesel charge. When the engine is stone cold and the glow plugs go out, the cylinder walls and piston will absorb the heat and reducing the temperature below the detonation temperature EVEN when compression kicks in. The GPs stay on in this period until the cylinder walls are warmed up enough to support the self-combustion process of the diesel engine.
Normally the computer measures the water temperature and calculates the time required until the cylinder wall is hot enough and uses that time to after-heat when the engine has first started. The cycle kicks in when the RPM goes above a certain threshold so you don't waste time while cranking the engine with the starter.
When you don't crank the engine after the pre-heat system has stopped, the after-heat system starts with maximum time to support the slow people who don't immidiately turn the key to start the engine.
What happens with combinations of these two I don't know
