Smoking after fitting new MAF on ml270 cdi

Britsons2019

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Aug 13, 2021
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Ml270
Hi all. My first post so hoping I got it rite... long story short. 2001 mercedes ml 270 cdi. I got all three brake issue lights on and car is running limp mode IE wont rev above 2500 rpm and very low power. Had a basic code reader done and it said lateral speed sensor fault ? and second fault code read MAF low voltage. I ordered both parts online. MAF came today so I did a quick swop and took it for a test drive Amazing it pulls ok now no restriction on rpm. Just the usual puff of black smoke on hard acceleration!! So I did about 10 miles to be sure it's ok. As I pulled back in to my village I was waiting at traffic lights and it started to miss fire and plumes of black / blue smoke when I pulled away.. very bad I couldn't see the traffic behind me. Got back home took the new MAF off and put back the faulty one. Road test and back to limp mode no blue smoke but a constant haze of black smoke constant haze on load or off load ? Break issue new part arrives tomorrow so hopefully that will sort brake warning lights ? Just this smoke issue is making me worry !!! Any ideas guys ! Just ordered another MAF to rule out a faulty new MAF
 

Martin 1

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Northants
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'05 CLK 200 auto Convertible. silver with blue hood.
Although mine's not diesel, my experience of MB parts service and prices has been surprisingly good, can't say the same about their workshop.
 

grober

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You have the 5 cylinder OM612 engine -they can have problems with the EGR valve or turbo seals----a lot of oil /exhaust gas in the inlet system may also contaminate any new MAF-so don't thro money away on new kit till you find any other problem.
 
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Britsons2019

New Member
Joined
Aug 13, 2021
Messages
3
Location
Doncaster
Car
Ml270
You have the 5 cylinder OM612 engine -they can have problems with the EGR valve or turbo seals----a lot of oil /exhaust gas in the inlet system may also contaminate any new MAF-so don't thro money away on new kit till you find any other problem.
Thank you your info sounds plausible? But I never had any smoke issues upto the time when it went limp mode around same time brake issue lights came on. I only found out the MAF had an issue when I got a fault code for brake problem
Hence changing the MAF which i now assume was causing the limp mode because after fitting new one all was ok no limp or smoke ! Just weird how it just went poorly after 10 mile run at no more than 70mph then sat at traffic lights misfiring at 850 rpm accelerate past 1500 rpm no miss fire but unbelievable amount of mixed black blue smoke ? Removed new MAF refit old MAF no misfire no blue smoke but very lite black haze at all rpm levels
 

coldy5

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Oct 2, 2010
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1
Location
ireland
Car
ml270cdi
Any news on your issue
My ml270 cdi has developed similar smoke problem
 

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