Ok I need help. My merc C220d w203 is having a proble it feels and looks like a misfire. It happen constant when I rev above 2000rpm to 3000rpm. Once the engine drops back to idle it take it from 5 seconds to a 60 seconds but it gets its self back under control and stops misfiring. While it is misfiring loads of white/Blue smoke comes out. And it stinks of unburnt desiel fuel.

I have plugged in a code reader there are zero codes and no EML. I'm not sure what could be causing it, it just started out of the blue this morning

  • It sounds like there's a stuck injector where it's always on. I believe they call this stiction. There are products which can take care of this for you like Howes Meaner Power Kleaner and Hot Shot Stiction Eliminator. – Pᴀᴜʟsᴛᴇʀ2 Aug 27 '17 at 15:27
  • If this was the case would it not have a bad idle? – Barkermn01 Aug 27 '17 at 15:45
  • I think a better way of putting what I'm trying to say is the injector is slow to close all the way. Getting the injectors cleaned is a great (and cheap) first step to diagnosing your issue. It happens quite readily and is easily dealt with. – Pᴀᴜʟsᴛᴇʀ2 Aug 27 '17 at 16:19
  • @paulster2 Aren't your comments here better posed as an answer? – zipzit Aug 27 '17 at 16:47
  • It's had a lot of redex diesel Run though it of late and it's running Shell V-Power Diesel at the moment which is supposed to help them keep clean. – Barkermn01 Aug 27 '17 at 17:21

So since this has been on here a while it turned out that while standard diagnostics did not get any codes a star diagnostics identified that the engine was moving a little too much turned out to be an engine mount was loose.

The reason for taking it into the Garage, in the end, was that the car started applying a Rev limiting factor it would lock me to no higher than 2000 RPM but no Engine Management light would come on.

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.