Aurora

I've had my car for about a month now, and it's been garaged up until this weekend when I was visiting a friend and had to park outside. The temperature the first night dropped down to the low 30s (upstate NY). The next morning I went to start the car as usual and when I turned the key the car seemed to engage, but then all of a sudden it started choking and puttering and shuttering for a good few seconds before fully starting.

The next day the same thing happened, this time it was in the 40s.

Has anyone experienced this before? Is it perfectly normal for a brand new car to have such a rough start on cold days? Could it just be a case of a bad tank of gas? Does it make any difference how long I hold the key in the start position while firing up the car?

I just filled my tank so tomorrow evening when I start it up I guess I'll see if it's the gas.

elchinocache

i have a 2001 c240 and now thats its colder it starts up a bit rough. i dont pay much mind to it since every car i've had before has done the same. my guess is that since there is not so much oil in the cylinders, when the pistons travels up the cylinder its a bit rough. thats what i think but i may be wrong.

nukblazi

mines been doing that since new... turn the key to the on position, wait a couple seconds, then start... that seems to help

Guest0001

My C320 seems to be vibrating alot during start up over the past few months. Some what annoying but nothing that bothers me really.

FrankW

mine did that when i was in SF for couple days over the summer, the temp dropped to 30-40's. Someone mentioned it was the auto choke feature to protect the engine or something. Forgot who mentioned it, but I had posted a thread about this topic before.

vadim

I once had a severe case of misfiring, about 2 months into car ownership. It happened in the morning and wouldn't go away until I shut the car down and restarted it. The dealer replaced one of the coils - they must have seen the fault codes thrown, although there were no messages on the MFD.

As a side note, morning start problems may also be related to carbon deposits that may build up if you shut the engine down before it warms up enough (such as if you start the car, move it to clear the driveway for a family member and shut it down still cold). This is known as a "lawnmower syndrome". To avoid this, let the engine run for a while, or better yet - drive around the block.

New owners generally tend to underrev the engine, trying to baby the car too much, which also causes carbon deposit buildup. To get rid of those, it is enough to take RPM to 4500-5000 several times a day, which usually is not a problem under normal driving conditions, especially with a stick. If you feel that yours is not the case, try this: switch to a lower gear and drive at ~5000 RPM for 5 minutes. This is called "Italian tune-up". Should be done on a warm engine. There exist TSBs prescribing exactly that (haven't seen one for MB, though).

czachari

With the temps falling to the low 30s. I was driving on the highway cruising in 6th gear at around 2000rpm. I needed to speed up a little so I gave it a bit more gas and I heard the S/C sucking air into the engine like it should. Unfortunately, at the same time I felt the shake accompanied by a droning sound ( like a washing machine in the spin cycle ) and some things around the car started rattling ( I guess the vibration hit their harmonic frequency ).
Once the RPM went over 2500 or so the vibrations went away. I tried this a few more time and made it happen every time. I tried it in 5th and it happened there too. I tried it in 4th and it did happen but a lot more subdued. Did not happen in 3rd or lower. This jappened to me long time ago and I explained it to the dealer and they said it was normal for the S/C to do this. I did not quite understand it but I have never driven any other S/C cars, only turbos. Anyone have an idea what this may be?


Thanks

CZ

p.s. It's not detonation(pinging)...

vadim

At 2000 RPM you were underreving the engine - this is below the RPM point where the engine produces enough torque. ~ 2500 RPM is exactly when it picks up. On top of that, you have heavy 18" wheels.

czachari

and/or timing retardation
What I don't get is that the engine actually pulled fine as if it was at 3000 rpm or higher. It just did it in a very uncivilized ( and very worrisome ) manner. I didn't think that a Mercedes Engine should sound and vibrate like a freaking washer on spin cycle.
I wonder if anyone else has experienced this.

Thanks

CZ


p.s. The 18x8 Konig Theory wheels are the same weight as the stock 17x7 C7 wheels.

CitronC230K_03

i had my car parked in the garage and hadnt started it in 4 days, because i car pooled to work with my brother. the avg. temp lately has been high 60's, maybe low 70's i think. anyhow when i did start my car yesterday to go to school, it was high 50's temp at 7am, and my car was very rough when ideling.

mtokfmak

Glad to know that my car is not the only car which demonstrates this problem. I had this rough idling three times over the past two months, and one was recognized by the computer as a misfire. The dealer checked the engine and test drove the car; however, no problem was found.
I have been recently following someone's post that leaving the key on the on position for a few seconds before igniting the engine avoids this problem, and it seems to work (though my dealer says that unless the engine is ignited nothing moves mechanically).

I would be very much interested in hearing sensible explanations and solutions to this matter.

vadim

They may weigh the same, but they introduce higher rotational inertia (=higher unsprung weight), being of larger diameter.

vadim

He forgot about the fuel pump. That would actually explain it - a few seconds in ingnition before cranking the engine must help build up fuel pressure in the system.

Aurora

ok, so i started my car the next day, after getting a new tank of fuel from a different gas station, and no problems starting the engine (outside temp. was the same as the previous day...40). so, the choking on start must be due to a bad tank of gas. and i got it from a "reputable" gas station... mobil... ghetto-looking one though. watch out for those.

mckaype

People,
On my 04 C320 I've not had rough starting, delayed cranking, or the shudders and shakes described.... even at single digit temperatures.

naidd

The rough start can happen because of a defective oil filter. There is a valve in your oil filter which prevents all of the oil from dropping down in the oil pan. This is so that when you start the car cold, there will be some oil in the upper part of your engine.

Sometimes, the valve would fail and would let the oil drop all the way down. When you start the car, the oil pump needs time to pump the oil to the top of your engine (sometimes 20-30 seconds), during which time your engine may run extremely rough.

This has happened to me a couple of times. It is no big deal, as long as you change your oil filter when you see it for the first time.

05Css

Well, not sure if this helps but I will type it any way. I was reading the manual and it states that you should pick (W) on older models or (C) on newer ones so the car can start in second gear for cold weather. That's for automatics though.

vadim

This has nothing to do with starting the engine. What you are talking about is getting the car in motion after the engine has been started.