S-Class (W222) 2014-2020

Misfire and CEL -- typical or no?

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 05-29-2019, 09:47 PM
  #1  
Newbie
Thread Starter
 
nuclearfishin's Avatar
 
Join Date: May 2019
Posts: 4
Received 0 Likes on 0 Posts
S550 (W222)
Misfire and CEL -- typical or no?

Normally a misfire wouldn't bother me much, replace a plug or coil, and it's usually good. Except, I'm still in a 7-day trial period where I can give the car back and walk away. I'm still under factory warranty so getting the misfire fixed isnt a problem, but I'm wondering if it's an ominous sign of things to come. The car only has 23k miles so that's not common for a plug or coil to go bad. Should I let the dealer fix it, or walk away while I can. Just curious if this is highly unusual or no big deal. Thanks.
Old 05-29-2019, 10:17 PM
  #2  
Senior Member
 
bkdc's Avatar
 
Join Date: Dec 2008
Posts: 373
Received 108 Likes on 82 Posts
2015 S550, 2017 GLS450
Well you know the answer. The worst case scenario is an actual issue with cylinder pressure, but a bad spark plug or ignition coil is the most likely followed by a fuel injector problem. If the car has pristine maintenance records, I wouldn’t be scared away and I’d have the dealer replace the plug or ignition coil. If I were buying from a private party, I’d be concerned whether the car was modded as aftermarket performance mods lead to early spark plug failure

Last edited by bkdc; 05-29-2019 at 10:21 PM.
The following users liked this post:
seamus2154 (05-30-2019)
Old 05-30-2019, 01:21 AM
  #3  
Super Member
 
steveb9771's Avatar
 
Join Date: Oct 2007
Location: Southern California
Posts: 643
Received 51 Likes on 38 Posts
2007 CL550
Ask for a cylinder compression check which is easy perform and may reveal if there is a serious issue.
Old 05-30-2019, 02:22 PM
  #4  
Senior Member
 
seamus2154's Avatar
 
Join Date: Jan 2019
Location: Palm Beach, Fl
Posts: 495
Received 194 Likes on 136 Posts
2016 S550 sport, 2018 GLC300, M3, Zo7, 2021 Sierra Denali
No it's not common. Could be something stupid and easily addressed IF its a good clean car with service records. If not, I would be concerned.
Old 05-31-2019, 06:29 PM
  #5  
MBWorld Fanatic!
 
Mitch Alsup's Avatar
 
Join Date: Sep 2014
Posts: 1,063
Received 354 Likes on 232 Posts
S600
Originally Posted by steveb9771
Ask for a cylinder compression check which is easy perform and may reveal if there is a serious issue.
Ask for a leak-down test, this can isolate things that compression test cannot.
Old 05-31-2019, 09:03 PM
  #6  
MBWorld Fanatic!
 
MBS63AMG's Avatar
 
Join Date: Mar 2017
Location: Birmingham, AL
Posts: 1,349
Received 490 Likes on 341 Posts
2019 S560, 2022 Audi S8
Originally Posted by nuclearfishin
Normally a misfire wouldn't bother me much, replace a plug or coil, and it's usually good. Except, I'm still in a 7-day trial period where I can give the car back and walk away. I'm still under factory warranty so getting the misfire fixed isnt a problem, but I'm wondering if it's an ominous sign of things to come. The car only has 23k miles so that's not common for a plug or coil to go bad. Should I let the dealer fix it, or walk away while I can. Just curious if this is highly unusual or no big deal. Thanks.

Mine had a misfire a month ago at 70,000 miles. Never really knew what happened, but they kept the car 3 days, did a computer update or two, I started using premium fuel and it has ran better than ever. They even said my plugs seem fine but it wouldn't hurt to have them changed at 80,000 miles. I'd be a little concerned since yours only has under 25,000 miles on it. The dealership should run a diagnostic on it.
Old 05-31-2019, 09:43 PM
  #7  
Junior Member
 
MrAK's Avatar
 
Join Date: Jul 2018
Posts: 29
Likes: 0
Received 3 Likes on 3 Posts
2015 S 550
I have a 2015 with 25,000 miles and had misfires a month ago. It would be triggered mainly when I try to accelerate (not aggressively) when the RPM is around 1000.

I went to the dealership and they said it was a bad coil for cylinder 1. Once they replaced it, I haven't had a misfire since.
The following users liked this post:
seamus2154 (06-02-2019)

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Misfire and CEL -- typical or no?



All times are GMT -4. The time now is 10:50 AM.