C63 AMG (W204) 2008 - 2015
Sponsored by:
Sponsored by:

Weird - intermittent CEL and coolant overflow

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Aug 9, 2014 | 10:50 AM
  #1  
BLKROKT's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2008
Posts: 8,074
Likes: 2,867
From: Los Angeles
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Weird - intermittent CEL and coolant overflow

Ok. So my car had been sitting for about a week while I installed my new ModeCarbon parts on the car. I didn't do anything to the engine, it was just a bumpers off job. I headed to Island Dragway last night for a couple more runs stock, and have encountered a few problems...

1. As soon as I turned the car on, I had a CEL light. Car sounded fine, and I got in and drove it easy for the 60mi or so from the city to Island. I figured if something went/felt wrong, I'd just watch my buddy run. No problems getting there whatsoever.

2. At the track, when I turned the car back on, the CEL was gone. I tried plugging in my MyGenius to see if it would read codes (have NOT flashed yet), but apparently it doesn't.

3. Made 2 passes. No traction at all from my bald rear Conti's (18" Nitto 555R's are getting put on Monday morning- thanks for the info superlubricity). MPH was very barely fractionally down (1mph). Hit 240deg oil temp at the end of my first run, and 250deg after my second. Fairly normal, maybe a little high but the runs were back-to-back.

4. Started looking around, and noticed that there was some white smoke coming out of the DRIVER SIDE TAILPIPE ONLY. Smelled like condensation - no coolant, no oil - although there was zero coming out of the passenger side tailpipe (dripping water condensation). Sounded like MAYBE the car was missing slightly at idle but I could be imagining that.

5. Started to snoop around a bit more, and found this under the hood:
Weird - intermittent CEL and coolant overflow-photo-1.jpg


Looks like my coolant overflow reservoir puked all over my engine bay at some point in either this drive or the last. I know this is brand new because my engine bay is spotless.

Driving home late last night, oil temps stayed around 217deg cruising on the highway, while water temps were anywhere from 180deg (which is the coolest I have ever seen so far), up to a not un-normal 200deg. It fluctuated back and forth up and down the whole drive - seemingly more than usual. When I got to the city and slowed down, oil temps went to 240deg, and stabilized at 230deg - 10deg higher than usual. Water temp was normal at 197deg.

So we have a CEL turning on and off, an overflowing coolant reservoir, and somewhat erratic temps.

SO... the question is does this sound like a head gasket or a misfire in the drivers side bank? Would the car throw codes for either or both? And what is the best thing I can get to read codes within reason? Many thanks guys, this one has me a little stumped...
Reply
Old Aug 9, 2014 | 11:31 AM
  #2  
BLKROKT's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2008
Posts: 8,074
Likes: 2,867
From: Los Angeles
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Just to add two things - the car was at the dealer last Wednesday for an oil change as I need to find a reasonable dealer around here and figured that'd be a good way to check out their operations. I asked them to pull any codes and just give it a thorough once-over as I drove it 8k miles so far this summer. Everything came back fine, clean bill of health. They changed the oil and added some sort of fuel additive - I assume it was just injector cleaner. That was the last time I drove the car. The CEL light went off at the track after I added 5gal of Sunocco race gas.
Reply
Old Aug 9, 2014 | 01:25 PM
  #3  
m a x i m u s's Avatar
MBWorld Fanatic!
 
Joined: Sep 2005
Posts: 3,165
Likes: 59
C63 AMG P30 *EuroCharged*| Porsche Cayenne | Buell XB9SX
id say either your res cap is bad or the dealership didn't tighten it down all the way if/when they checked levels. was it loose?
Reply
Old Aug 9, 2014 | 02:04 PM
  #4  
BLKROKT's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2008
Posts: 8,074
Likes: 2,867
From: Los Angeles
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Yeah, I'm at my car now and the coolant res cap was loose. However the cap doesn't 'click' or catch like I'm normally used to. Is that normal? Could be a bad cap throwing the CEL? Smoke was maybe just condensation (on startup after the track session after sitting for 2hrs). Then heat issues would be caused by too low coolant maybe. Hmm will go get some distilled water and top it off then. Thx for the suggestion.
Reply
Old Aug 9, 2014 | 05:56 PM
  #5  
m a x i m u s's Avatar
MBWorld Fanatic!
 
Joined: Sep 2005
Posts: 3,165
Likes: 59
C63 AMG P30 *EuroCharged*| Porsche Cayenne | Buell XB9SX
Originally Posted by BLKROKT
Yeah, I'm at my car now and the coolant res cap was loose. However the cap doesn't 'click' or catch like I'm normally used to. Is that normal? Could be a bad cap throwing the CEL? Smoke was maybe just condensation (on startup after the track session after sitting for 2hrs). Then heat issues would be caused by too low coolant maybe. Hmm will go get some distilled water and top it off then. Thx for the suggestion.
if you still have warranty, I'm sure the faulty cap would be replaced for free. of course, it's prob not that expensive either. just a thought.
Reply
Old Aug 9, 2014 | 06:02 PM
  #6  
BLKROKT's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2008
Posts: 8,074
Likes: 2,867
From: Los Angeles
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Still have warranty. The cap does not feel right at all. Will prob just order one from OEdiscountparts.com. Thx.
Reply
Old Aug 9, 2014 | 06:43 PM
  #7  
Ingenieur's Avatar
Banned
 
Joined: Jul 2013
Posts: 2,811
Likes: 7
C63 AMG
They overfilled the coolant
Should only be 1/2 full when cold
There is a tab in the reservoir

They did mine too
Goofy temps til I siphoned some out
Reply
Old Aug 9, 2014 | 06:47 PM
  #8  
BLKROKT's Avatar
Thread Starter
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Jun 2008
Posts: 8,074
Likes: 2,867
From: Los Angeles
2012 P31 C63 Coupe Trackrat, 2019 GLE63S Coupe Beast
Ah ha there's the answer. Thanks dude.
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

 Verdad Gallardo
story-1

6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

 Verdad Gallardo
story-2

Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

 Verdad Gallardo
story-3

Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

 Verdad Gallardo
story-4

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-5

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-6

Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

 Verdad Gallardo
story-7

Mercedes EQS Gets A Major Update: Everything You Need to Know

 Verdad Gallardo
story-8

5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

 Verdad Gallardo
story-9

Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

 Verdad Gallardo
Old Aug 9, 2014 | 07:05 PM
  #9  
Mort's Avatar
MBWorld Fanatic!
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2010
Posts: 5,649
Likes: 484
2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
If you have to top off the coolant use a 50-50 mix with the proper MB coolant to maintain the 15 year coolant life.
Reply

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


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


All times are GMT -4. The time now is 12:06 AM.

story-0
New Electric Mercedes-AMG GT 4-Door Coupe Unveiled: 10 Things You Need to Know

Slideshow: Mercedes-AMG's new electric GT 4-Door Coupe trades combustion for software, synthetic noise, and more than 1,100 horsepower.

By Verdad Gallardo | 2026-05-20 20:08:15


VIEW MORE
story-1
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-2
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-3
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-4
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-5
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-6
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-7
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-8
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-9
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE