skpatel

Yesterday I replaced the thermostat in my 2006 C280 4Matic (65,000 miles). I was getting CEL with code P0128 (Coolant Temperature Below Thermostat Regulating Temperature). I learned it was the thermostat. I was sure the stealer would hit me with $800 for all the work. I was little skeptical in the beginning to replace it myself but then just dived in. I decided to replace the serpentine belt and drain the coolant while I was replacing the thermostat. I have used the forums a lot to learn about my car and thought I should contribute. So, I took some pictures and created a DIY procedure. The pdf file is attached here. It is a fairly simple process. I hope it helps.

W203E35

Very good DIY, THANKS!!!

GotDaBenz

Hey, you are good! That is a real pro job, much appreciated.

omg its nate

Nice, I had mine replaced under warranty a few months ago.

Javvy

Excellent DIY.............good job..........thank you so very much.....

allen_7

Great DIY, thank you very much.

Taiwanese

Thanks.
We need more people like you.

edawg

Thank you for the detailed steps on how to replace the T-stat. I am currently unemployed and have little money, so I am doing this work at home. Your pictures and description are great.
God Bless

JLD2k3

Glyn, is this basically the same for a C320?

jsohigian@yahoo

In your post you did mention that you DIDNT HAVE TO drain the antifreeze, right?

Also, When you take that hose off some antifreeze is going to come out right? How much?

If it is minimal I shouldnt have to worry about adding any?

Also, where did you find the thermostat/parts etc.?

thanks!

pcy

on-line places to buy parts: AutohausAZ dot com and RMeuropean dot com. Both have free shipping above $50 and $75 purchases respectively.

About the amount of coolant when thermostat is removed... If I were you, I would have a new gallon of coolant and 1 gal of distilled water ready before starting with the process of replacing the thermostat.

JLD2k3

On the C320, you don't have to drain the coolant or remove any pulleys. You just pull the old one off and put the new one in, then top off the coolant.

jsohigian@yahoo

Does it have to be "mercedes coolant"?

Thanks for the quick reply...

ALLDATAdiy INFO

Very nice work!

skpatel

I did not have to drain the coolant to replace the thermostat. You will lose very little coolant. You can add distilled water to bring level back if you did not drain a lot of coolant. I thought it was worth replacing the coolant since my car had 60,000 miles on it. I bought the parts from MB dealer. It was not any cheaper at AutoHausz or other places. So it is better to pick it up from dealer. Also, coolant cost is around $17/gal at dealer. Since I was saving so much money by doing it by my self, I spent money buying it from dealer. I would warn to anyone who is considering to use standard coolant from local pep boys etc. Do not use this as these coolants have different charcteristics and could damage your engine. Not worth the risk ($17).

Outkasted24

WOW, How Funny!
I turned 65k miles a couple weeks ago and to my Surprise this past weekend, CEL out of the blue!!
I ran up to Autozone the other night to have them check out the CEL and I also came up with a P0128.

I picked up a Thermo and both ring gaskets today at my TampaBayMB dealer and plan to swap out the Thermo tomorrow or Sunday.

I just clicked on your PDF file but can't seem to get it to load.
Is the file still available?

samaritrey

works fine for me

jsohigian@yahoo

Should I replace the serpentine belt when I do the thermostat?

Also, someone wrote CEL? What does that mean?

When I replace the thermostat will the check engine light just automatically go off, assuming nothing else is wrong?

Thanks for all the help. I get the part tomorrow and will put it in tomorrow night.

ontmiss

CEL means check engine light and will not go off automatically, you need OBD2 scaner to erase code. For belt it's up to you, check in what condition is belt and if it has any cracks.

jsohigian@yahoo

Sounds good for the belt. Any reccommendations for brand or model for the OBD2 scanner?

aljajoly

This is a great job, thanks, it is exactly the same for the R350 models. Very easy wit this type of documentation.

Where can I get an OBD2 scanner?

edawg

So I decided to do this work on my own. When I opened the hood of my C230 sports sedan, it looked very different from the C280 on your pictures. I am sure it's probably just the "dressing".

I am going to create a DIY doc for my C230 T-Stat replacement, but want to thank you for getting me motivated to do it myself! I ordered the parts today from MyMercedesParts.com and they were very nice over the phone. Total parts ~ $37.00 and that includes shipping! ($24.99 T-Stat and $1.88 o-ring)

Bought my Zerex G05 from the local O'reilly Parts, they were no help I felt like walking into a Ford dealership, these bozos had no clue what I was asking for, so I showed them the part - - on their O'reilly web site!

OK, parts should be here no later than Monday and then is off to DIY!

Taiwanese

edawg,

Please make sure you make a new thread so it's easier for C230 owner to search in the future.

Thanks from a C230 owner.

jsohigian@yahoo

So I just got my Actron Auto Scanner and I love it! It came up with P0128, so i will def replace the thermostat tomorrow.

Also, the thermostat that I got, is an OEM thermostat from Wahler.

In the DIY, it shows a picture of the thermostat that is faulty. The one that I received, looks the same way, "open" as described in the DIY.

Makes me nervous.. What I dont understand is that, that piece is spring loaded so wouldn't it stay open?

Please help.

jsohigian@yahoo

Victory!!!!!!!

Thanks for all the help. I just replaced the thermostat and so far so good.

PCY- you were so right. IMHO you have to drain the coolant because when you take off the hose, it just starts spewing out.

Coolant and distilled water is must.

Also, I have a 2006 C280 4matic and it was VERY challenging to get the thermostat off. Also, that top bolt was a B&*(h to get at and take off.

Thanks again for all the help. This site and blog is a life saver. It did take me a little longer than anticipated..