Nomoney
Member
- Joined
- Feb 1, 2016
- Messages
- 12
- Reaction score
- 0
- Location
- Worcs
- Your Mercedes
- B class Cdi & W211 E Class
Hello, I have a really annoying issue with my wife's B Class that recently developed. The background story relates to an injector issue and the car sounding like a box of nails on cold start up. Turns out it needed an replacement injector and this issue was resolved. However, now it has developed an issue at idle when warm only.
When warm the engine sort of hunts during idle. The rev needle does not move but you can hear the engine note changing and feel the vibration, almost like you are blipping the throttle just a little bit.
The really annoying bit is the car is not throwing any codes at all as checked by STAR. From my limited experience my thoughts are towards the following, MAF sensor, MAP sensor, EGR, O2 sensor or maybe a vacuum leak.
This is what I have checked so far, breather pipes, cleaned EGR, cleaned MAF sensor, cleaned MAP sensor and replaced fuel filter. Sadly non of this has cured the issue.
One thing I noticed recently is if you unplug the MAF sensor the idle returns to normal. So this was replaced with a new part and the problem is the same still. If the MAF is unplugged it returns to normal, I assume when unplugged the ECU defaults to other parameters for the fuelling and therefore whilst it may seem to be MAF sensor related its not really?
I must admit to be a little confused and frustrated by this issue. So before I start replacing expensive parts, I though I would ask if anyone has any ideas or pointers of which way to go now.
Thanks in advance for any help.
When warm the engine sort of hunts during idle. The rev needle does not move but you can hear the engine note changing and feel the vibration, almost like you are blipping the throttle just a little bit.
The really annoying bit is the car is not throwing any codes at all as checked by STAR. From my limited experience my thoughts are towards the following, MAF sensor, MAP sensor, EGR, O2 sensor or maybe a vacuum leak.
This is what I have checked so far, breather pipes, cleaned EGR, cleaned MAF sensor, cleaned MAP sensor and replaced fuel filter. Sadly non of this has cured the issue.
One thing I noticed recently is if you unplug the MAF sensor the idle returns to normal. So this was replaced with a new part and the problem is the same still. If the MAF is unplugged it returns to normal, I assume when unplugged the ECU defaults to other parameters for the fuelling and therefore whilst it may seem to be MAF sensor related its not really?
I must admit to be a little confused and frustrated by this issue. So before I start replacing expensive parts, I though I would ask if anyone has any ideas or pointers of which way to go now.
Thanks in advance for any help.