Mercedes Sprinter 9 speed automatic

[Roger S]

We have just collected our new van and we are very pleased with how quite it is and how smooth the box is but ! when driving slow and I think it is mainly when going downhill at slow speed it seems to drop down a gear and rev quite high which is not great when trying to run it in. Does anyone have any ideas what is going on ?

 

[Silver-Fox]

We have just collected our new van and we are very pleased with how quite it is and how smooth the box is but ! when driving slow and I think it is mainly when going downhill at slow speed it seems to drop down a gear and rev quite high which is not great when trying to run it in. Does anyone have any ideas what is going on ?

No idea.

But running in, is that still a done thing?

 

[Hettie's Crew]

There’s nothing wrong with revving quite high, not under load.

 

[Roger S]

Apparantly so, it says in the destruction manual not to rev it too high or at the same speed for long periods, but I just dont like to hear an engine rev when its not necessary.

 

[Googlebot]

All the autos with similar boxes I have had do this.

Suits the regeneration system on them and saves wear on the brakes.

You could drive it in manual if it is revving too high for you.

I haven’t in any of the ones I have had but they have all been leased and gone back after three years. No issues with any of them.

^{_{Subscribers  do not see these advertisements}}

 

[Silver-Fox]

Apparantly so, it says in the destruction manual not to rev it too high or at the same speed for long periods, but I just dont like to hear an engine rev when its not necessary.

During a running in period revs and how long for need varying otherwise you get a step in the cylinder walls.

When the engine is finally “stretched” it can do harm to the rings.

 

[Just smiffy]

It’s called engine braking and is normal…

 

[Roger S]

You wouldnt change down like that with a manual box.

 

[Westbarn1]

I have the same auto/engine in my new Hymer, I'm guessing the engine management is detecting you are on a downhill and changes down to provide engine braking, which is better than riding down on the brakes, in fact I normally get in first, on a steep hill, and manually change down, to stop the descent speed. getting too high. Was in the Pyrenees recently and found that I could easily get up to the red area on the rev counter on a steep descent, which is when I'd start using the brakes. As stated in post 3, it's not that the engine is under load. Just keep an eye on the oil level, I found I had to source some correct spec engine oil while I was away, as the level dropped while we were away (4k miles in 10 weeks) and its a real pain topping up without a dip stick, oil level can only be checked whilst the engine is running and on level ground.

 

[EuroTrotters]

Over ride it.

It’s just a combination of YAW sensor signals / PCM sensors communicating with the ESP module through to the engine and gearbox ECU”s.

The 9G-Tronic is a much improved version over the 7G-Tronic and 7G-Tronic+ . It’s designed to do what you describe . I doubt there are problems with any sensors

^{_{Subscribers  do not see these advertisements}}

 

[Roger S]

It's progress then ! I will keep my eye on the oil level too thanks.

I really dont like the idea of red lining the van or any diesel engine, it just sounds so wrong. I never red lined my Morris 1000 and that lasted years.

 

[MR BLO]

I am pretty certain that the engines are bench run before they leave the factory. My last new car even stated that in the owners manual. It suggested that one should try to avoid running at the same rpm for extended periods (like on cruise control) for the first 1000 miles.
It’s right to be concerned, you have thrown a lot of cash at it, but I am with the others here and suggest that there is nothing to worry about unless you plan to drive her like an Italian taxi.
Happy travels.

 

[jongood]

You wouldnt change down like that with a manual box.

Correct. My ML does it, its really annoying, revving its nuts off when there is no need.

I've never managed to override it with the paddles, its particularly annoying in slippery conditions

 

[funflair]

Ours will do it as well but if I click the retarder on before senses it needs engine braking and drops a gear it overrides it and descends all serene and quiet.

The Telma retarder is an option on Iveco Daily chassis and some truck chassis.

 

[Westbarn1]

The Telma retarder is a great bit of kit (but heavy), I believe they fit them on MB Sprinter based ambulances, but, no good on current FWD models!

^{_{Subscribers  do not see these advertisements}}

 

[EuroTrotters]

The Telma retarder is a great bit of kit (but heavy), I believe they fit them on MB Sprinter based ambulances, but, no good on current FWD models!

posh bit of kit that.