Drooke11

So my 2009 c63 threw a P0128 last night. I know the code is thermostat. Here's my question since I have researched everywhere and cant seem to find it. I checked my coolant level it was full. Car wasn't over heating. Oil temp = 200F Engine temp = 200F It was about 45F where I live last night. So here's my story.... I left work didn't really let the car warm up got on the high way and kinda beat on it. Will these cars throw these codes if the car isn't at proper operating temp? Also my oil temp flashes till it hits about 175F is this normal? Sorry if these are stupid questions i have been in corvettes my whole life. This is my first benz.

chrisridebike8

Does your car not have an owners manual? Regarding the flashing oil temp, it's normal. It's telling you not to beat on it because the oil isn't up to a safe operating temp yet.

As far as the CEL code, no they won't throw codes for that. You might need a new thermostat.

Drooke11

Thanks! Nope car didn't come with a owners manual!

abcut973

You don't need an owner's manual to know that these big block NA V8 needs to be up to temperature in order to beat properly on it!
And no the CEL has not come up because you beat on your car when engine was cold. It came because a failing condition was reported by the ECU for a least a full driving cycle. It just means you have something wrong going on. In your case it is thermostat related. And as Chris said maybe a bad one. GL

Drooke11

So I have another question. Since my thermostat is going out and I bought this car modded. How do I tell if it's a stock thermostat or a aftermarket 180F?

abcut973

Hum no idea. It is not a common mod to have an aftermarket thermostat on the c63. There are really no major gains having this.
What other mods do you have? Any pictures will help.

Wobble64

put a stock one in no matter what is in at the moment. But I would first confirm it needs to be replaced.....
P0128 means the car did not warm up as fast as expected. As long as it gets warm eventually it is not a serious issue. However, the thermostat may be leaking coolant to the radiator even when the car is still cold.


Observe it for a while and replace it if the car heats up too slow. A thermostat is not a big deal.