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...

 

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.

 

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.

 

Easy replacement. P0128 means the car is taking too long to, or not reaching operating temperature. Benz thermostats fail open.

 

do ihave to change my coolant?

 

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...

 

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.

 

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.

 

Yeah Tommy happens to all of them in the long run.

 

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.

 

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.

 

+1

 

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...

 

Cancel the code & see if it returns.