Check engine light + Multiple misfires
Thread Starter
Newbie
Joined: May 2018
Posts: 13
Likes: 0
From: Ontario
C63 507 Sedan - Sold \n F80 M3 Stage 2 - Sold \n C63 507 Coupe
Check engine light + Multiple misfires
Hi all, I picked up a 507 coupe about 3 months ago. Ever since I have been chasing this check engine light and multiple misfires.
Mods/Info:
- MBH Headers, Midpipe, Eurocharged V7 tune and K&N Filters.
- Car is a 2015 with 77,000kms
What I've tried so far:
- New spark plugs (OEM from dealer; corrected gap to 0.040"; torqued to 22Nm or ~16ft-lbs)
- New O2 sensors (Bosch OE upstream/primary)
- New ignition coils (OEM from dealer)
- New air filters (K&N, plus removed charcoal filter)
- Cleaned MAF sensors 3 times
- Tested battery with a multimeter (OEM battery replaced 2 years ago)
- Oil changed with Liqui-Moly 5W-40 (Oil cooler drained, OE filter, torqued to spec)
Codes:
- Small EVAP Leak (this is very rare and only happens every 5 or so times I fill up for fuel; doubtful this is related. Maybe a fuel filler neck.)
- Random misfire on multiple/unknown cylinders
- Misfire on cylinders 2,3,4 and sometimes 8
Pretty bad misfiring during cold start. Sounds like a cammed corvette, unfortunately not in a good way.
Also, I know these cars are just awful on fuel, but my dash displays approx. 13L/100KM on the highway in comfort. In reality by tracking km and fuel usage, I am getting more like 19L/100km
Any help on this is much appreciate! I am not a mechanic and may be missing something obvious - I'm all out of ideas.
Thank you!
Mods/Info:
- MBH Headers, Midpipe, Eurocharged V7 tune and K&N Filters.
- Car is a 2015 with 77,000kms
What I've tried so far:
- New spark plugs (OEM from dealer; corrected gap to 0.040"; torqued to 22Nm or ~16ft-lbs)
- New O2 sensors (Bosch OE upstream/primary)
- New ignition coils (OEM from dealer)
- New air filters (K&N, plus removed charcoal filter)
- Cleaned MAF sensors 3 times
- Tested battery with a multimeter (OEM battery replaced 2 years ago)
- Oil changed with Liqui-Moly 5W-40 (Oil cooler drained, OE filter, torqued to spec)
Codes:
- Small EVAP Leak (this is very rare and only happens every 5 or so times I fill up for fuel; doubtful this is related. Maybe a fuel filler neck.)
- Random misfire on multiple/unknown cylinders
- Misfire on cylinders 2,3,4 and sometimes 8
Pretty bad misfiring during cold start. Sounds like a cammed corvette, unfortunately not in a good way.
Also, I know these cars are just awful on fuel, but my dash displays approx. 13L/100KM on the highway in comfort. In reality by tracking km and fuel usage, I am getting more like 19L/100km
Any help on this is much appreciate! I am not a mechanic and may be missing something obvious - I'm all out of ideas.
Thank you!
Newbie
Joined: Nov 2021
Posts: 3
Likes: 1
From: New England
2012 C63 AMG - p31 package
Same except mine at 76k miles. I had a cam adjuster rattle on start for a while and then one day car started misfiring and shaking like crazy on highway. Got it towed to my local Indy. Codes were all indicating misfires in right bank. Got the cam adjusters replaced in that bank along with solenoids and sensors. No more rattle on start up and car runs great. (Did new plugs and injectors too for preventative)
Thread Starter
Newbie
Joined: May 2018
Posts: 13
Likes: 0
From: Ontario
C63 507 Sedan - Sold \n F80 M3 Stage 2 - Sold \n C63 507 Coupe
@mr747 Thank you for the feedback. I will try a smoke test to see if there are any visual leaks.
If I end up removing it, might as well replace the gasket while I'm in there
If I end up removing it, might as well replace the gasket while I'm in there
Last edited by james_duro; Sep 2, 2022 at 04:10 PM. Reason: Adding username
Thread Starter
Newbie
Joined: May 2018
Posts: 13
Likes: 0
From: Ontario
C63 507 Sedan - Sold \n F80 M3 Stage 2 - Sold \n C63 507 Coupe
Same except mine at 76k miles. I had a cam adjuster rattle on start for a while and then one day car started misfiring and shaking like crazy on highway. Got it towed to my local Indy. Codes were all indicating misfires in right bank. Got the cam adjusters replaced in that bank along with solenoids and sensors. No more rattle on start up and car runs great. (Did new plugs and injectors too for preventative)
My father's M156 CLS63 needed this back in the day. It only had 10,000km at the time
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Joined: Apr 2013
Posts: 339
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1998 E300TD
Experiencing something similar. According to the data is a vacuum, pcv, or intake leak causing my cold start misfire woes.
smoke test and visualyl inspect all the vacuum lines. Also check intake bolts to see if you have a loose one. Don’t tighten it down if so. Get a new one, they are tty bolts
smoke test and visualyl inspect all the vacuum lines. Also check intake bolts to see if you have a loose one. Don’t tighten it down if so. Get a new one, they are tty bolts
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