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First time posting here and i’d like to thank everyone for their knowledge. It’s been invaluable to me!
Currently i’ve run into a new challenge with my W204. Noticed it took longer to get the optimal running temp for the engine (OM651) usually 90C. Anyways i disconnect the hose leading to the thermostat to have a look and its full of corrosion and water is dripping out. Made me believe the suspected thermostat has a leaking seal and must be replaced. I have attached a few pictures so everyone can learn from my situation. My question is; WHERE DOES THE RUST COME FROM? WHAT DO I DO ABOUT IT? Pipe leading to the thermostat
Last edited by MBislyf; May 1, 2024 at 02:38 PM.
Reason: Too many photos
Yes the rust is from past coolant in the system that was mixed with tap water probably
get some coolant flush and flush the system. Flush until you get clean water out. Then use the pre mix coolant to refill after you have drained it completely.
Im thinking the wrong coolant was used. I cant tell if thats rusty water, or just the wrong color coolant. Im far from an expert so when i was about to drain and replace my coolant I tried to do research whats best to mix new coolant with and I kept coming up with either tap water or demineralized water. I went with Zerex coolant.
To make it even easier i bought the Zerex 50/50 premix coolant made with demineralized water. My 2010 W204 uses the Blue G48 coolant, later models use the Pink G40 I believe. I found the Zerex cheap at a local Napa auto parts store.
I would drain and fill the system a few times until its clean. Tap water should be fine for cleaning everything out. Then id do the final fill with 50/50 premix.
I wonder is a stop leak type product was used? Im just guessing.
I apreciate your replies. I have this car sinse 2 years. Last year around June i did a full flush of the system via the radiator drain because the color of the coolant seemed to have deteriorated from a light bluish-green to orange. After using distilled water to flush system several time i then added pre-mixed coolant and bled the system. Could it be i have used the wrong coolant or maybe residue water in the system? How do you identify the right coolant for the OM651?
Did anyone check the video. Is the thermostat done?
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