Manitoba deli wrote:Starting and driving imediately will dramaticaly decrease the life of your diesel engine. It is recomended to let the engine warm up even in the summer for a few minutes. The heat generated by the combustion of deisel is tremendous, and driving a cold diesel engine will cause the engine to warm up unevenly. this causes uneven wear, warping, and glazing of many parts. Just because a diesel engine can be driven right away doesn't mean it should be. If you want to get the longest life out of your engine, let it warm up. Of course this is only my opinion as a diesel mechanic for over 20 years. I have no documented proof of this, I've only seen the damage caused by cold driving on engines I've had to work on.
This is actually the opposite of everything I have ever read/heard about diesel engines.
Diesels generate very little heat at idle, it is actually bad for a diesel engine to idle for extended periods, this is why big-rigs have a "high idle" function to let them put the revs up when idling for extended periods. Now on a 1993 and earlier delica you have a hand throttle, but this is not so on newer delicas, as such you should never idle them for extended periods.
Diesels should be driven as soon as the oil pressure comes up (usually about 10-20 seconds), but driven gently for the first few minutes until they have warmed up evenly. (that part we agree on)