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Just got a CEL yesterday. Cleared it and it came back today after driving home.
Ran it through STAR and I am getting a P0128. Thermostat.
Prior to this ZERO CEL's and problems. Car seems to still drive fine. But I DO believe it was taking slightly longer for the car to heat up and or it might be a bar or two lower on the dash for the engine temp..
Just wondering what people's thoughts are. I will be doing the work but just wanted to verify. I searched and it appears there are different thermostats for the w211. I'm not entirely sure which one is needed for our 2009 e350.
VIN: WDBUF56X29B432025
Is this also something that I should replace the water pump? I don't mind doing stuff while I am already there, coolant drained...etc.
I found this on Pelican Parts:
Genuine MB: https://www.pelicanparts.com/More_In...4625&DID=15025
I don't mind buying OEM/Genuine...etc. That's not an issue.
Don't mind the overhead console fault. I had it removed when the windshield was being redone the other day. I just didn't clear the faults. They were only stored and not current/present.
Thanks much,
-Nigel
Last edited by NewShockerGuy; Dec 21, 2020 at 07:01 PM.
Wahler is the oem maker of the part. I'd check things like the oil cooler gaskets and see if they're leaking. Thermostat, pulleys have to come off to get to it. If it's just the thermostat, I'd also consider changing the pulleys/tensioner if you haven't already done that. I've done that to both M272 engines, both pulleys and tensioner/belt tend to make noise. One of the pulleys has to come off anyway when you change the thermostat. You mileage is low but I did do pulleys/tensioner at around the 60k mark. As to where to get it, as long as it's a Wahler, anywhere should be fine. I think I got mine on Amazon or Rockauto.
Wahler is the oem maker of the part. I'd check things like the oil cooler gaskets and see if they're leaking. Thermostat, pulleys have to come off to get to it. If it's just the thermostat, I'd also consider changing the pulleys/tensioner if you haven't already done that. I've done that to both M272 engines, both pulleys and tensioner/belt tend to make noise. One of the pulleys has to come off anyway when you change the thermostat. You mileage is low but I did do pulleys/tensioner at around the 60k mark. As to where to get it, as long as it's a Wahler, anywhere should be fine. I think I got mine on Amazon or Rockauto.
Awesome thank you. So there is no need to then get the OEM MB part for $120 when the Wahler or $60 is the same thing? Wonder why the MB branded part is double?
Good tip about the tensioners and belts. I actually replaced the spark plugs, idler pulleys, and the OEM belt back in 2017 at 57,338 miles. So that stuff has about 4k miles on it. I think it should be ok. I don't hear anything out of the norm. The tensioner I don't believe I did, so I can assume that it's probably the factory one from 09'. I will probably replace that just for safe measure.
Awesome thank you. So there is no need to then get the OEM MB part for $120 when the Wahler or $60 is the same thing? Wonder why the MB branded part is double?
Good tip about the tensioners and belts. I actually replaced the spark plugs, idler pulleys, and the OEM belt back in 2017 at 57,338 miles. So that stuff has about 4k miles on it. I think it should be ok. I don't hear anything out of the norm. The tensioner I don't believe I did, so I can assume that it's probably the factory one from 09'. I will probably replace that just for safe measure.
Appreciate the info!
-Nigel
That's how OEM works. When you get the Wahler part, compare it to the original MB part. On the Wahler, there's a spot where there would be an MB logo but it looks like someone took a grinder and scratched it out so they probably both came off the same line, just modified afterwards for the parts not going to MB.
Also I noticed you're getting a coolant temperature sensor. I'd wait on installing that. It doesn't normally go. Usually only gets replaced when the temperature is still low after replacing the thermostat. In my situation, after replacing the thermostat on both cars, temperature went back to normal. Just a bad thermostat.
Also I noticed you're getting a coolant temperature sensor. I'd wait on installing that. It doesn't normally go. Usually only gets replaced when the temperature is still low after replacing the thermostat. In my situation, after replacing the thermostat on both cars, temperature went back to normal. Just a bad thermostat.
That's good to know! I bought it because it was only $18 for the OEM one and I figured since I'm replacing the thermostat, replace the sensor just for good measure as well. Also figured since it was almost 12 years old it wouldn't hurt?
But that's a good point. Don't replace a bunch of stuff. Drove today after I cleared the code and it didn't come up. I am noticing though it's like a click or two for the bars below 80C. Normally I think it's always around 80C. I haven't changed the coolant since I've had the car now for a couple years so it's probably good this happened so I can get new fresh coolant in the car.
That's good to know! I bought it because it was only $18 for the OEM one and I figured since I'm replacing the thermostat, replace the sensor just for good measure as well. Also figured since it was almost 12 years old it wouldn't hurt?
But that's a good point. Don't replace a bunch of stuff. Drove today after I cleared the code and it didn't come up. I am noticing though it's like a click or two for the bars below 80C. Normally I think it's always around 80C. I haven't changed the coolant since I've had the car now for a couple years so it's probably good this happened so I can get new fresh coolant in the car.
-Nigel
It seems a little involved to do it but I guess if you have the time, not too big a deal. In the winter it's usually a little on the low side. The coolant is 15 years/150k. When I did mine, I figured it was still good so I just topped it up. I think I used about a gallon so I got a decent amount out anyway. Basically just Zerex G-05, although I think there's a different one out now that will also work.
Replacing thermostat is no problem. Getting to the rear temp sensor is a huge pita. I can't do it. I can see it with my mirror but can't get the first bolt off in order to remove the bracket that is holding the temp sensor in. Why they designed it like this is assaine. If the one plug wasn't blocking the 2nd plug and bolt it wouldn't be nearly as bad.
Time to fill up the system and see what happens.
EDIT. Finally got it the old sensor out and the new one in.. GD! What a pita.
-Nigel
Last edited by NewShockerGuy; Jan 18, 2021 at 11:37 PM.
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CEL: P0128: Thermostat Problem?
