noodlesoup

every morning when i start my car, the engine seems to run very hard. and when i drive it without warming it. it will have like 2k rev when i am driving 10mph. but the problem is gone if i warm up the car. is this normal for c240?

jpb5151

At least with our c230k, the manual states that the engine'll rev a bit higher at first just to warm up the catalytic converter. We get about 3 blocks and then it'll go ahead and upshift normally. hth

noodlesoup

so is it good or bad for the engine if i don't warm up?

pokerFACE

you dont need to warm up the car by letting it idle.. in fact, it takes longer to warm up the car that way.

you should start the car, let it sit for about 10 seconds (so that the revs fall to just under 1000) and then drive away (take it easy though)

...the 2k at 10mph part.. i'm pretty sure that's because the transmission didnt upshift.

I'm no techie, but there is two reasons for that: 1) engine is not warm therefore running at a higher rev to warm it up and/or 2) tranny isnt warm therefore not shifting properly/delaying upshift to warm up.

MB///HRV

Yes, It's perfectly normal. The reason behind it is to get the engine warmed up. So when you drive off it will shift at higher rpms to try and warm the eangine up faster.

pokerFACE

...thanks for the assist HRV!

...just remember if you want to make it upshift anyway, you can always nudge the Touchshift to the right.