davatk

I've noticed recently that my new E350 Bluetec likes to hang in low gear when I first start the car up and head out some days. Mostly if the car hasn't been started for a day or so. After getting to the end of my drive (about 3/4 of a mile) and getting on the main road it seems to shift OK.

Anyone else notice this ?

thanks in advance.

ImInPA

Diesels tend to do this to help warm them up. Diesels are very thermally efficient. This "keeping the revs up" helps them heat up to get the catalytic converter up to temp quickly and to get the engine warmed up. I love my Bluetec.

listerone

My BMW diesel does the same thing...particularly in colder weather.I shift manually for the first couple of miles in order to keep RPMs down and after that short time everything's normal.

I've read that this is typical of late model diesels but my "d" is the only one I've ever owned.If I take the plunge on a new Bluetec (I signed an order and put down a deposit today but am having second thoughts) I'll be sure to watch for this.

LaicepsYdobon

It's normal and more porminent when the weather is cold outside. The reason why the car hangs onto lower gears is to produce higher RPMs which in turn would produce more heat and bring the engine up to operating temperature faster. This is completely normal. You should not try to outsmart it by shifting manaully to keep the RPMs down. The engine needs to be warmed up to be at its peek efficiency.

Dooty

My E350 BlueTec does the same. Check page 152 of the owners manual, "Upshifts take place at higher engine speeds after a cold start. This helps the catalytic converter to reach its operating temperature more quickly."

davatk

Excellent ! Thanks for pointing that out. Makes me feel a lot better about the behavior I was concerned about...