C-Class (W203) 2001-2007, C160, C180, C200, C220, C230, C240, C270, C280, C300, C320, C230K, C350, Coupe

engine light throwing code (p0128)... need advice (glyn or anybody who knows)

Old Mar 9, 2011 | 02:54 AM
  #1  
pogijeffrey's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2008
Posts: 267
Likes: 0
05 c230 kompressor
engine light throwing code (p0128)... need advice (glyn or anybody who knows)

thanks again to karo for coming through helping to check my engine light.. so this is what i got "coolant thermostat" error... i went and did my search on this forum but i wanted to know from others who experienced this problem and wondering what would be my best option. could i fix this on my own or should i just take it to a professional..? and what should i replace going on to fixing this error... need advice...

i have a 2005 c230 with 130000 miles on it already.. my car hasnt overheated at all... ive actually been driving with this engine light for quite a while with no problems at all... i could say more than 6 months.. i just figure it was an 02 sensor... car runs great just feels like the supercharger doesnt work.. engine light went away a few times and thats when it ran great... and now its on for good... so again thx to karo for helping me out...

Last edited by pogijeffrey; Mar 9, 2011 at 02:59 AM.
Reply
Old Mar 9, 2011 | 06:08 AM
  #2  
Ryan619's Avatar
Newbie
 
Joined: Feb 2010
Posts: 10
Likes: 0
2005 w203k
Yup it's the thermostat. Just had my replaced. $30 piece and you most definitely can do it yourself. What happens according to my uncle is the little spring can get worn which throws the code. I actually helped him replace it but don't know enough terminology to explain it, but I swear I saw diy on it. Let me see if I can find it.
Reply
Old Mar 9, 2011 | 06:15 AM
  #3  
Ryan619's Avatar
Newbie
 
Joined: Feb 2010
Posts: 10
Likes: 0
2005 w203k
Found it. https://mbworld.org/forums/c-class-w...edan-w203.html It's for the 03' but it's basically the same. You're gonna have a little coolant spillage but not to the point you have to replace all of it. Just be careful prying out the plastic covering the thermostat. It took some force but we got it out.
Reply
Old Mar 9, 2011 | 07:42 AM
  #4  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Easy replacement. P0128 means the car is taking too long to, or not reaching operating temperature. Benz thermostats fail open.
Reply
Old Mar 9, 2011 | 12:54 PM
  #5  
pogijeffrey's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2008
Posts: 267
Likes: 0
05 c230 kompressor
do ihave to change my coolant?
Reply
Old Mar 9, 2011 | 01:58 PM
  #6  
pogijeffrey's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2008
Posts: 267
Likes: 0
05 c230 kompressor
hey glyn, i drove the car like this for quite a long time(months) assuming it was just an o2 sensor problem... could i have damage something not replacing the thermostat on time??? i mean the car runs great and no problems what so ever...
Reply
Old Mar 9, 2011 | 05:17 PM
  #7  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Just top up the coolant as necessary. You will not do damage in a couple of months - don't worry.

Not running hot enough does accelerate wear & reduce efficiency but you would have to go a long long way to do damage.
Reply
Old Mar 10, 2011 | 08:10 AM
  #8  
tommy's Avatar
Out Of Control!!
 
Joined: Nov 2001
Posts: 10,067
Likes: 11
From: Westwood, NJ
2004 Civic Si. FWD for the Win!
It's been a good run for my original thermostat, but looks like it's time for a replacement. Got the P0128 code myself this morning.
Reply
MB World Stories

The Best of Mercedes & AMG

story-0

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

 Verdad Gallardo
story-1

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

 Verdad Gallardo
story-2

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

 Verdad Gallardo
story-3

8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

 Verdad Gallardo
story-4

Flawlessly Restored Mercedes 190E Evo II Heads to Auction

 Verdad Gallardo
story-5

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

 Verdad Gallardo
story-6

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

 Verdad Gallardo
story-7

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

 Verdad Gallardo
story-8

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

 Verdad Gallardo
story-9

10 Most Reliable Mercedes-Benz Models You Can Buy Used

 Verdad Gallardo
Old Mar 10, 2011 | 10:16 AM
  #9  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Yeah Tommy happens to all of them in the long run.
Reply
Old Mar 11, 2011 | 01:12 PM
  #10  
tommy's Avatar
Out Of Control!!
 
Joined: Nov 2001
Posts: 10,067
Likes: 11
From: Westwood, NJ
2004 Civic Si. FWD for the Win!
Ok, so is P0128 really the code, or is it P0126? I'm pretty sure that the code I got is P0128, which is undefined, and since there are those here who have had the same code with the same issue (it did take a long time to get above 80 deg C on my commute home last night), either I read it wrong and it's really 0126, or it's just a weird thing that the car throws a code that is not exactly defined.
Reply
Old Mar 11, 2011 | 01:25 PM
  #11  
pcy's Avatar
pcy
MBWorld Fanatic!
 
Joined: Mar 2004
Posts: 1,175
Likes: 24
From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
All generic OBD-I and OBD-II codes are pre-defined.
P0128 is related to cooling system - specifically, coolant is not reaching operating temp within a specified time interval.
Reply
Old Mar 11, 2011 | 04:47 PM
  #12  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
+1
Reply
Old Nov 5, 2011 | 03:21 PM
  #13  
msheredy's Avatar
Super Member
 
Joined: Jan 2007
Posts: 617
Likes: 1
From: San Diego
MB
I just responded to an older post, didn't see this one. My wife's car has been having this problem as well and we've already had the thermostat replaced so I was wondering if there's something else that my be at fault like a sensor perhaps?
Reply
Old Nov 9, 2011 | 11:33 PM
  #14  
pogijeffrey's Avatar
Thread Starter
Senior Member
 
Joined: Jul 2008
Posts: 267
Likes: 0
05 c230 kompressor
Originally Posted by msheredy
I just responded to an older post, didn't see this one. My wife's car has been having this problem as well and we've already had the thermostat replaced so I was wondering if there's something else that my be at fault like a sensor perhaps?
no that was it... i replaced my thermostat and coolant, at the same time replaced transmission oil and fuel filter. i had my friend reset my engine light. never came on ever since...
Reply
Old Nov 10, 2011 | 08:07 AM
  #15  
Glyn M Ruck's Avatar
Super Moderator
MBWorld Ambassador

 
Joined: Jun 2008
Posts: 19,942
Likes: 192
From: Llandudno, Cape Town, South Africa
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Cancel the code & see if it returns.
Reply

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

Thread Tools
Search this Thread
Rate This Thread
Rate This Thread:
You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 12:53 PM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE