W205 C63S 2019 misfiring

[K44HNO]

Hi all

I have an issue with my W205 C63S, only in the mornings on cold start the car misfires but once warmed up the misfire seems to smooth out. Star machine states cylinder 2 misfire, I have replaced with a brand new coil pack and had the injectors checked along with new spark plugs but the problem still persists. Anybody else had this issue? Any help will be greatly appreciated. @Jobsworth any chance in giving me any suggestions?

Thanks

 

[ALFAitalia]

Compression check?

 

[K44HNO]

Compression check?

Hi, yes this is the next plan have the car booked in for tomorrow morning for this. Let's see what that brings back.

 

[Jimmyc63s]

Hi all

I have an issue with my W205 C63S, only in the mornings on cold start the car misfires but once warmed up the misfire seems to smooth out. Star machine states cylinder 2 misfire, I have replaced with a brand new coil pack and had the injectors checked along with new spark plugs but the problem still persists. Anybody else had this issue? Any help will be greatly appreciated. @Jobsworth any chance in giving me any suggestions?

Thanks

Is your ECO start stop button working? Have you noticed it not being illuminated green even you press it "on" or "off"? Keep an eye on that because if it fails to work it's 99% a bad injector.

 

[K44HNO]

Is your ECO start stop button working? Have you noticed it not being illuminated green even you press it "on" or "off"? Keep an eye on that because if it fails to work it's 99% a bad injector.

View attachment 149588

Hi, thanks for your reply, I just went out to check this and it seems as though the stop/start is working fine, I can switch it on/off with the button (illuminates green when on). Have you had a similar issue? Thanks

 

[K44HNO]

Hi all

Just thought I'd update people interested in the issue I have, compression check was done both electronically and mechanically and came back as all good. However I then decided to get a sniff test done. This unfortunately changed the colour of the sniff test indicator from blue to green indicating the exhaust gasses were making their way into the coolant. Ie head gasket is done. I live in Manchester. Is there anyone who can recommend within the northwest who is experienced in carrying out this work? Thanks in advance.

 

[Spider10]

This guy has a caravan next to me and seems a pretty genuine guy and loves anything AMG

 

[K44HNO]

This guy has a caravan next to me and seems a pretty genuine guy and loves anything AMG

Thanks for this, will contact him later today, do you know if he has done a head on a M177 before?

 

[oldguy57]

Hi all

Just thought I'd update people interested in the issue I have, compression check was done both electronically and mechanically and came back as all good. However I then decided to get a sniff test done. This unfortunately changed the colour of the sniff test indicator from blue to green indicating the exhaust gasses were making their way into the coolant. Ie head gasket is done. I live in Manchester. Is there anyone who can recommend within the northwest who is experienced in carrying out this work? Thanks in advance.

SPR Autos in Stockport seem to do AMG and forum members on here have suggested them before. Might be worth contacting them to see what they can do. Merctech in Manchester seem to have mixed reviews.

 

[K44HNO]

SPR Autos in Stockport seem to do AMG and forum members on here have suggested them before. Might be worth contacting them to see what they can do. Merctech in Manchester seem to have mixed reviews.

Thanks for this will check them out also, have tried Merctech before for another issue I wasn't too impressed with them

 

[Spider10]

Thanks for this, will contact him later today, do you know if he has done a head on a M177 before?

Im not too sure i got talking to him about my SLK55 AMG but to be fair a Head is a Head as long as you dont take to much off it hope you can sort it

 

[Smitty1]

Ever since ive had my merc ive always used MPH prestige in Rochdale, who were recommended to me by someone on here, always done a a really good job and always had great service

 

[philnewmerc]

out of curiosity how many miles has it done? Seems a bit drastic to have head gasket failure so young, bad luck

 

[K44HNO]

Ever since ive had my merc ive always used MPH prestige in Rochdale, who were recommended to me by someone on here, always done a a really good job and always had great service

Thanks mate, appreciate your help, will contact them too.

 

[K44HNO]

out of curiosity how many miles has it done? Seems a bit drastic to have head gasket failure so young, bad luck

Tell me about it, car has done 60k though but I would never have expected the gasket to go with this much mileage. Its not a massive amount of miles.

 

[Skd884]

Very unusual and possibly mapped at some point......

 

[K44HNO]

Very unusual and possibly mapped at some point......

I agree, I always thought these engines were bullet proof, maybe mapped but not by me.

 

[tylerdurden]

Is it sorted? What did it cost?

 

[K44HNO]

Is it sorted? What did it cost?

Head gasket mate, must have been a vey tiny crack on the gasket, exhaust gasses were escaping into the coolant. Tested the coolant and it failed the leak test. Water must have been getting into the cylinder overnight hence the reason why the misfire was worse in the morning than during the day. I sourced another engine and swapped them over instead of repairing the head. Not a nice experience.

 

[ALFAitalia]

Seems a bit extreme for a simple head gasket job..........or was there more too it. Seems more of a risk to fit an unknown used motor to me....