Engine idling and automatic gearbox

[Goldreef]

Hi,

I have noticed a couple of small things with my C270 cdi that I was wondering if someone could offer advice on please? (Its a 2003 classic se auto, with 31,000 miles)

The first thing is that after starting the engine from cold, the car idles alittle eratically. When the engine is still cold the revs rise and fall between around 500-900 (approx). I have read some of the forum guides and was wondering if this could be the MAF sensor?

The second thing is the automatic gearbox is very occasionally alittle eratic (sorry I haven't managed to ascertain if this happens when running cold or whether it happens when the engine is at operating temp).

Sometimes when I press the accelerator to pull away from stationary, the car feels like it is struggling to pull away. Even with the revs at around 2,000-3,000 the car barely moves, and I have noticed this once or twice when reverse parking too.

Tonight I was pulling away on a slight incline, and the car would barely move with the revs at 2500 or so. So I stopped, held the car on the footbrake, and when I let off the footbreak to pull away again, it started to roll backwards, which I know isn't meant to happen when the gearbox is in drive. But once you get going, its fine again. Can anyone offer any advice on this please? I know this needs to go for repair, but I would like a rough idea of the problem, so the dealship does not try to pull a fast one.

Any advice would be very much appreciated,

John

 

[television]

Hi john, as far as I know the MAF does not affect idle, do you have 2 faults here, hopefully some answers in the morning

 

[Goldreef]

Hi Malcolm, thank you for getting back to me. As far as I am aware the two problems are unrelated.

Not sure if my concerns are maybe something in nothing, however I'm sure when the car goes in for it's next service in January, the technicians will pick up any possible difficulties.

Many Thanks,
John

 

[Parrot of Doom]

How long does the erratic idle last for? Glow plug failure perhaps?

 

[jberks]

Not sure what is affecting your idle but if the idle is low, it may be more willing to roll back. Older autos didn't roll back at all but the newer ones, such as yours and mine can do, depending on the incline. If your idle is low, it may roll earlier, so I suspect the problems may be related.
Low idle / hunting is often a vacuum issue - I'd check the vacuum hoses as a first step.

 

[JimSharp39]

wonky rolling gearbox

Have you checked the fluid level in the g/box? I had a ford sierra once (sorry) that exhibited similar characteristics and I found the fluid level to be low.
Jim

 

[Bolide]

Does this sound like a torque convertor problem?

Nick Froome
www.w124.co.uk

 

[jberks]

When you say 'barely moves'. Do you mean that the speed is lower than it should be for the gear and engine revs, or that the acceleration is poor?
(I took the latter but others are going on the former).

 

[BlackC55]

Does this sound like a torque convertor problem?

Nick Froome
www.w124.co.uk

Could be.....

It needs plugging in and testing.

 

[Goldreef]

Hi,

Thank you for all your replies, your help is very much appreciated.

I dont have any problems in starting the car, which I thought may be associated with a glow plug problem, however this would be worth having checked.

The car usually idles at about 600 rpm when started, and will be alittle erratic while it is cold for say about the first 10 minutes, with the rpm bouncing around 600 - 900 rpm.

When I referred to the car barely moving, I meant that the car would stuggle to even pull away from standstill, with the rpms in excess of 2000+ , rather than just sluggish performance (almost like the gear was not engaging properly).

Admittedly the incline was not that great (it was on my driveway), it just felt like the car was in neutral to be honest.

The areas for which I will be having checked intially are the vacuum system, the automatic gearbox fluid and also glowplugs. I will mention the symptoms to my Mercedes dealership, so that they can hopefully identify something on the Star system.

Thank you once again for your help, very much appreciated. I'll let you know how I get on once Mercedes have had a look.

Kind Regards,
John

 

[britnordic]

Cold & slow off the mark?

I've got a 2003 C270 cdi Estate and experience that same slow uptake when cold. First couple of times I even wondered if I had selected "Drive" ?
With 46k on the clock I'm praying it's nothing serious. Our previous C200 cdi had to have a new torque converter & gearbox after only 55k, thankfully just under warranty.
Once warm everything is brilliant.

Tony.

 

[Goldreef]

Hi,

Just a wee update to let you know that my gearbox trouble was due to a leaking multi plug seal in the gearbox. The multi plug seal and transmission fuild have both been replaced and the gearbox is running perfectly

Many Thanks,
John