2010 e350 - got the CEL off but the mechanic says it's "misfiring like crazy"?
02-04-2023 | 02:55 PM
#1
Thread Starter
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Joined: Dec 2022
Posts: 5
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From: New Hampshire, USA
2010 Mercedes-Benz e350
2010 e350 - got the CEL off but the mechanic says it's "misfiring like crazy"?
Hey all,
I was having major misfires so I did up my plugs and coils. It went great (well, on the second try. The first try i forgot to plug in coil 6 🤣
and the CEL went off the next day while i was tooling around. This was about a week ago, havent driven all that much since. Brought it in to inspect and they said "its misfiring like crazy" and wanna take it to diagnose. Now, my little $30 scanner still reads the codes from before i did the coils as stored but theres no pending codes, no permanent codes, no CEL. Sure, it idles a bit inconsistently cuz my gasket's on its way out but i'm not feeling any misfires and ive been staring down my instrument panel and never see the CEL throw.
If it's detecting misfires is it gonna throw the light 100% of the time? Is this tech on to something or should i just take a long drive and try a different mechanic? Any advice would be appreciated, thanks everyone
I was having major misfires so I did up my plugs and coils. It went great (well, on the second try. The first try i forgot to plug in coil 6 🤣
and the CEL went off the next day while i was tooling around. This was about a week ago, havent driven all that much since. Brought it in to inspect and they said "its misfiring like crazy" and wanna take it to diagnose. Now, my little $30 scanner still reads the codes from before i did the coils as stored but theres no pending codes, no permanent codes, no CEL. Sure, it idles a bit inconsistently cuz my gasket's on its way out but i'm not feeling any misfires and ive been staring down my instrument panel and never see the CEL throw.If it's detecting misfires is it gonna throw the light 100% of the time? Is this tech on to something or should i just take a long drive and try a different mechanic? Any advice would be appreciated, thanks everyone
02-05-2023 | 05:24 AM
#3
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Joined: May 2018
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From: Jakarta-Indonesia
2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
If your scanner has Mode 6 OBD2, use its misfire count feature. You need to drive the car or at least see last 10 cycles.
Mode 6 can read misfire as-is . DTC of misfire will only appear as DTC when certain counts are reached.
Mode 6 can read misfire as-is . DTC of misfire will only appear as DTC when certain counts are reached.
02-06-2023 | 02:27 PM
#4
Member
Joined: Dec 2021
Posts: 144
Likes: 70
From: Calverton MD 20705
2013 W212 E350 RWD
Hey all,
I was having major misfires so I did up my plugs and coils. It went great (well, on the second try. The first try i forgot to plug in coil 6 🤣 and the CEL went off the next day while i was tooling around. This was about a week ago, havent driven all that much since. Brought it in to inspect and they said "its misfiring like crazy" and wanna take it to diagnose. Now, my little $30 scanner still reads the codes from before i did the coils as stored but theres no pending codes, no permanent codes, no CEL. Sure, it idles a bit inconsistently cuz my gasket's on its way out but i'm not feeling any misfires and ive been staring down my instrument panel and never see the CEL throw.
If it's detecting misfires is it gonna throw the light 100% of the time? Is this tech on to something or should i just take a long drive and try a different mechanic? Any advice would be appreciated, thanks everyone
I was having major misfires so I did up my plugs and coils. It went great (well, on the second try. The first try i forgot to plug in coil 6 🤣
and the CEL went off the next day while i was tooling around. This was about a week ago, havent driven all that much since. Brought it in to inspect and they said "its misfiring like crazy" and wanna take it to diagnose. Now, my little $30 scanner still reads the codes from before i did the coils as stored but theres no pending codes, no permanent codes, no CEL. Sure, it idles a bit inconsistently cuz my gasket's on its way out but i'm not feeling any misfires and ive been staring down my instrument panel and never see the CEL throw.If it's detecting misfires is it gonna throw the light 100% of the time? Is this tech on to something or should i just take a long drive and try a different mechanic? Any advice would be appreciated, thanks everyone
Barring that, you've addressed only spark. You need to address fuel and air. Clean your air intake filter, service your throttle body, PCV etc. Once you've determined that to the best of your knowledge and ability that there shouldn't be anything wrong with your intake system, address fueling. If your fuel pumps aren't moving enough fuel for the injectors to fire off correctly, there'll be a misfire. Is your fuel filter clogged? Are your injectors junked up? If your fuel ,air, and spark should all be functioning to the best of your knowled, you need to do a compression and cylinder leakdown test.
The following 2 users liked this post by AllPhonesAretap:
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02-06-2023 | 04:41 PM
#5
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Joined: Apr 2019
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From: Silicon Valley
MY'14 W212 M276 3.5NA @60kMi
gasket misfiring like crazy...
This is when your scanner has a chance to pay for itself.
It's hard to help you fix something right when we don't know what's wrong with engine.
There are multiple types of misfires: single cylinders or ramdoms. Hopefully you only have a single cylinder misfiring
Look at LT fuel trims data for lean correction worse than -5 points.
It's hard to help you fix something right when we don't know what's wrong with engine.
There are multiple types of misfires: single cylinders or ramdoms. Hopefully you only have a single cylinder misfiring
Look at LT fuel trims data for lean correction worse than -5 points.
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AllPhonesAretap (02-09-2023)
