primatives

hey guys just wondering is it necessary for a turbo timer on the diesel ml's?? i heard it keeps the turbo in good shape??

dgiturbo

Never heard of anyone with one. With the MB electronics, it would be an expensive install. I usually just drive slowly through my suburbs (speed limit is 25MPH anyways) till I pull into the driveway. By then the turbine has cooled enough to just switch off.
By the way, newer (2013's) and European diesel MB's now have start stop technology which switches off the engine almost at every traffic light. I would hope things were designed to handle that life cycle, which would eliminate the need for a turbo timer.

AudiA4Turbo22

Honestly, I have a BIG turbo in my Audi and it is recommended to allow the turbo to cool prior to shutting off the engine. However, instead of spending ~$500-600 on a turbo timer and going through the headache of installing it, all you need to to is let the car idle for 30 seconds before turning it off. By the time you unbuckle your seat belt, grab your things, open your door, etc. you should be fine. I have yet to have a problem with this method.

Also, Mercedes takes ALL of this into consideration when designing, OEM cars are built to withstand the most oblivious drivers of all, those who get into a car after not driving for 4 days or so, fire it up and before the idle even stabilizes, have the car in reverse/drive, foot on the gas and A/C blowing.

Here's what I suggest:

1. In the mornings allow the idle to stabilize prior to driving off. Also, be very easy on the gas until the car has reached its proper operating temperature.
2. Avoid heavy accelerations for about a mile before parking(hard to do if you live on a hill like me, but if you do just give it some extra idle time to cool down).
3. Let the car idle for 30-45 seconds before shutting off the engine.

You should be trouble free if you follow these steps.

primatives

thanks man!!! I will do that!!!!

roadrutz

You probably won't do any damage because the problem with turbos used to be that if you switched off the engine while they were hot, the oil inside them would get so hot it would coke. Next time you started the engine, it would take a while for the coked oil to blow through, during which the turbo would be spinning essentally unlubricated. But it is extremely hard to get Mobil 1 or any other good synthetic to coke, no matter what you expose it to. I would think the biggest problem today with switching off while the turbo is red hot would just be the heat soak that would take place in the vicinity. The new BMW twin-turbo V8 has both an auxiliary water pump (the turbos are water cooled) and an auxiliary oil pump that both keep running after the engine is switched off until the turbos reach a specified temperature, but that may be as much to do with their location -- in the V above the engine -- as with lubrication. Don't want to be burning the paint on the hood!

jkaetz

I suspect that MB is using a similar system for the bluetec engines. My wife's has a high pitched whine that sounds an awful lot like a pump of some sort that runs for 30 - 60 seconds on key off. The bluetec turbos are also up toward the top of the engine toward the firewall.

iankayem

The need for Turbo Timers relates to air cooled turbos which were fitted (often aftermarket) to the precombustion diesel engines. As Roadrutz said, the oil could cook when its supply shut off, as the oil flow did the cooling in the core of the turbo.

But to my knowledge, almost all modern direct injection engines come with water cooled turbos. With these even if the water does boil within the turbo on shutoff, the steam rises to be replaced with fresh water on the thermo syphon principle. (remember some 1950's and earlier cars did not have waterpumps at all!)

Auxillary water pumps will obviously guarantee safe cool downs are achieved.

But personally, I drive the turbo diesel as if it were a petrol, except that I would still take my time in shutting down if I towed a heavy load up a steep mountain.