C220 Cdi Manual (w203) (HELP)

[faisalamir50]

Hi i have posted before about this car, in first the car wasn't even starting when it started there was large knocking noises and a lot of smoke after that, i found out that the injector in 4th cylinder was leaking, i got it replaced from a merc specialist and conrod was bent so i got it changed from someone not far from my house, ex mechanic, most of the knocking noise went away and so did the white smoke, now it is still knocking, and there is still some lack of power, i replaced the maf it is better but knocking has still not gone away, and knocks even more when under load and still low on power, i think it might be one of the following and need help:

1) Might be another injector but not coming up on OBD2 so how do i check it
2) Might be a Bent Valve but how do i know and check
3) The mechanic never replaced the sheels in the conrod, can it be it and how do i know
4) Might be a Piston problem as when i rev the engine fast i get some blue smoke
5) Last one could it be simply a knock sensor, how do i check it and where is it

Can some please get back to me thanks

 

[Xtractorfan]

A compression test will give you an indication of valve or piston problem, bent valves wont seal properly, I would have thot that the piston, rings and conrod would need changing. You really need an experienced ear to listen to the noise. and I feel the head may need to come off....

 

[Ellsy Tanners]

Unplug electrical plug on each injector in turn, it will run rough but if the knockig stops hey presto its that injector.

 

[faisalamir50]

Hi and Thanks

Thanks for your reply, i will do i compression test on each cylinder but how does that indicate if it is the bent valve or piston/rings and also should it be safe for the car to be started and then i remove the connection from each injector