Warming up and Cooling Down.
 

Hey all, just had a quick question, with my 300E I would always let it warm up everymorning, if I was in a hurry I would still make myself let it warm up for a minute rather than just taking off. I never let it cool down though, just shut it off when I got there.. So my question is, Is it necessary to let my 240D warm up? and also to let it idle for a bit before shut off? Just curious! :D thanks!

I would let it warm up a bit before driving but there is no need to cool it back down.

ok cool, thanks! :)

I'll just add some clarification to 79Mercy's response. Your 240D has a naturally aspirated engine and cooling down is not necessary. Cooling down periods are critical on turbocharged engines. Letting the engine idle for a short period of time prevents coking of the oil in the turbo bearings.

When I bought my naturally aspirated E300D, I had to relearn my shutdown procedure after driving turbo diesels for over 10 years.

Good to know, thank you for the explanation.

At least here on the "left" coast diesel is $4.50 or more a gallon. Warming up is a complete waste of fuel. If the starting idle is smooth and the oil pressure is normal, drive it gently for the first few miles. The only time one should warm up a car is to clear the glass of fog on a cold winter morning. By nature, diesel fuel contaminates the engine oil, so prolonged idling cold will add more raw diesel to the crankcase.

This is one of those hotly debated issues: whether to warm up or not. I don't: I subscribe to the theory that an engine's higher oil pressure under load has a better chance of distributing oil throughout the engine more rapidly than at idle.

What everybody does agree on is that if you don't warm up, you should drive gently for the first few minutes. If the uphill on-ramp to the highway is right outside your door, maybe I'd consider warming up first...

I fire up, wait a moment for the oil pressure do go up and drive. Generally I have to wait in traffic for about 5 min right outside my home. By that time the car has reached 70*c or 82*c. I also refrain myself from going over 2000 rpm if the water temp hasn't reached 82*c.