The owners manaul might not mention what is best
 

Does the owner’s manual tell you to take it easy in your diesel until it reaches operating temperature, not to shut it off before it reaches operating temperature, or not to rev it in neutral? Running the piss out a motor cold will cause a tremendous amount of damage, shutting off a cold motor will too, and revving high in neutral greatly increases the likelihood of spinning a bearing. Furthermore not even close to as much is known as what is today. ;)

Interesting post. I have not in the 14 years of owning Turbo diesels allowed the turbo to cool prior to shutting the engine down. But not a bad idea. My MD80 calls for a 3 minute cool down at idle prior to shuting it down and its just a Real Big Turbo.
However I must add that in the 14 years of owning Mercedes turbos I have NEVER had any problems with the turbos in the cars I've owned, Knock on wood. They include 2-300TDs (150,000 and 190,000 miles) , 86 300SDL (275,000 mi) and a 99 E300 Turbo diesel (75,000mi).

Dave

Usualy I think the lag just gets worse
 

We have 7 Benzes and all of them have a noticeable amount of turbo lag except the ones with 320k+ and 67k... All the other diesels are in between those two in terms of mileage. I do agree that these motors do not run very radical turbochargers and will sustain much less damage than a Cummins that rely heavily on the turbocharger for power.

Sorry last post unclear
 

By more lag I mean that it will get more and more lag the higher mileage it gets due to the bearing wear caused by the burnt oil eating away at the turbocharger's bearing. The car with 320k+ has always been allowed to idle down since we have owned it and according to the last owner.

Does the taxi in time count as "cool down" on the MD80?

Do the M/B use synthetic or dino oil?

Have you shut any of them off immediately after a hot, high speed run?

cool down-equalization of stresses?
 

Perhaps does not apply to mercedes but an old mechanic once told me it eliminates hot spots in engine prior to shutting down after hard use. That does equate to less cracking tendencies if true. Never saw what harm a cool down period would do prior to shutdown anyways. If I ever own a 603 type believe would leave at idle while getting a coffee or something to eat on the interstates for sure. Some have already mentioned this. After I locate a spare late numbers head for a 603 cheap will buy a car then never need the head. I know what would happen if I did not have the extra head. :) Would no cool down make more 603 owners crack addicts? :)

Here is a "cheap" 603 engine ($710 at present time).
NEW head !
I almost missed it looking for engine it wasn't found, then motor. Oh well, OM means Oel Motor ;)
I would snag it if I were anywhere NEAR Northern FLA :(
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7954232618&category=33615

Oh yes, I generally never have to cool down after a run unless I am coming down off a freeway where I have been running fast and hot, then I idle down a few minutes or leave it running while I fill up

you telling me that you mercedes has 320000+ miles. Wow, your car special.
me mommy told me i special two. lag? what is lag? :indian_ch

aluminum is up to more than 50 cents a pound now. i like recycling. good on the environment

Sold at $1400. :mad:

Not cheap anymore.

what not cheap? sold what?

Thats still not bad for $1,400 if the head is a 22.

Cool down period is at idle. so taxiin will count as the cool down period. We ussally try to use the left engine only for taxi so the right is cooling down.

All the oil in the MD80 is synthetic.

My Mercedes use dino oil. My SL uses synthetic.

The only time you would immediately shut and engine down after a hot , high speed run would be on a takeoff abort and evacuation. In that situation we would be running the engine at max takeoff power, if called for, and abort at a speed up to V1 (go-no go decision speed). Stop on the runway and evacuate. But your probably on fire in this situation. So to save lifes you don't worry about the aircraft.

Dave

I was thinking the M/B after a hot high speed run, not the MD-80. :eek:

It has a #18 head.