'Sticking' needle on speedo

[SimmoTech]

I've just bought my first Merc (E320CDI estate) and have noticed a minor problem with the speedo:-

When accelerating hard, up to around 50mph the needle goes up smoothly but then seems to stick and then jump forward (in increments of around 5mph) until 80mph or so and then it is fine again.

I mentioned this at a Merc dealership and they said the dash panel needed to be replaced at a cost of around £250. I assumed that it just needed a bit of lubrication! (Everything else works fine so I'm not going to pay that for a minor irritation)

On the other hand, is its position fixed to that of the digital speed signal? I changed the display to show MPH and that also jumps a bit - I would expect that of a digital display but not an analogue needle.

Any ideas?

 

[Arnie]

The whole instrument panel on the E-class works on CAN-bus. Either the needle has a mechanical problem causing it to stick, or the CAN-bus data is not being properly decoded by the CPU. Check if the increments are evenly spaced which might indicate a CPU problem, rather than a mechanical one, which might be more random.

The dash can be reprogrammed by a dealer and this may help.

If you can extract it (thin hooks required to pull in the corners), they are easy to dismantle and if it's a mechanical sticking problem it should not be difficult to sort, as long as the needle bearing is not damaged.

 

[SimmoTech]

Thanks for the reply.

The problem doesn't always occur so I'm hoping that the needle is sticking and I'll have it checked next time the car is at the garage.

Cheers
Simon