I bought my C180 (reg 2002 - 42k miles - automatic - petrol) 4 months ago.

not long ago I noticed a jerk/knock noise when shifting from 1st to 2nd gear. An emgine fault warning light appeared too.

I've had the car looked at by an approved Merc Garage and identified a problem with the ECU (engine control unit). They told me that the ECU was full with oil that travelled from the engine through some cables and fed onto the ECU.

Since then I've had the cables replaced, oxygen sensors, a filter put to stop from happening again and a new ECU fitted (over £1000).

The engine management warning disappeared but the jerk/knock is still there.

The garage had a look at the MAF sensor and gear oil (level and colour) and explained that they both looked fine.

It sounds like a mechanical fault with the gear box.

I am getting rather desperate atm. Any ideas or suggestions?