Idling after driving won't hurt it but is not necessary. Gasoline
engines have hotter exhaust than diesels so idling them after driving is
an excellent idea but diesels' relatively lower exhaust temperature are
benign on turbos. Turbos on our diesels usually last the life of the
engine's other major components - without special treatment.
Keep in mind that the factory doesn't want the car to idle for 5 minutes. That
long or longer and they want you to shut if off to prevent carbon from accumulating
in the prechambers. So, two mainutes tops I'd suggest.

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Martin Joseph - 21 Aug 2006 03:45 GMT
> Keep in mind that the factory doesn't want the car to idle for 5 minutes. That
> long or longer and they want you to shut if off to prevent carbon from
> accumulating
> in the prechambers. So, two mainutes tops I'd suggest.
This is kind of ridiculous, as obviously the car is going to be idling
for longer then 2 minutes when it is in service.
Richard Sexton - 21 Aug 2006 17:16 GMT
>> Keep in mind that the factory doesn't want the car to idle for 5 minutes. That
>> long or longer and they want you to shut if off to prevent carbon from
[quoted text clipped - 3 lines]
>This is kind of ridiculous, as obviously the car is going to be idling
>for longer then 2 minutes when it is in service.
Which is why howay driven cars have much cleaner engines than city
driven cars and why running some diesel purge through them helps.
Rediculous or not MB says if it idles for more than 5 minutes shut it
off and they've said this for years.
Having said that there are people that let their diesels run overnight
in extremely cold situations, but you do need then to deal with the
commensurate carbon buildup problems - diesel purge.

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Richard Sexton | Mercedes stuff: http://mbz.org
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633CSi 250SE/C 300SD | http://aquaria.net http://killi.net
> Idling after driving won't hurt it but is not necessary.
> Gasoline engines have hotter exhaust than diesels so
> idling them after driving is an excellent idea but diesels'
> relatively lower exhaust temperature are benign on turbos.
Cooling down the turbo isn't the reason that idling the engine
prior to shutting it off is sometimes recommended. If the
material in the turbocharger were all that sensitive to high
temperatures, it wouldn't have been used in that application
in the first place.
Rather, the reason is to ensure that the bearings have adequate
oil flow as the turbo spins down. The only time I bother to do
this is when I've been driving fairly fast and then park the car
without a transitional period of slower driving, such as when I
pull into a freeway rest area.
Geoff

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Richard Sexton - 21 Aug 2006 23:00 GMT
>Rather, the reason is to ensure that the bearings have adequate
>oil flow as the turbo spins down. The only time I bother to do
>this is when I've been driving fairly fast and then park the car
>without a transitional period of slower driving, such as when I
>pull into a freeway rest area.
This has been discussed at some length and the consensus seemed
to be if you use synthetic oil it'll hold up to the high temepratures
found in turbo bearings and you can just shut it down. But, if you
use dino juice it probably doesnt hurt to let it run a few minutes
to cool down a bit.

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Need Mercedes parts? http://parts.mbz.org
Richard Sexton | Mercedes stuff: http://mbz.org
1970 280SE, 72 280SE | Home pages: http://rs79.vrx.net
633CSi 250SE/C 300SD | http://aquaria.net http://killi.net