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Hi my w205 c300 engine light came on yellow. Car running fine. Took it to dealer who said it was thermostat. Not running hot via engine stats but dash gauge says one notch higher but still < 100. Temp warning light not activated. Any ideas on what it could be or how to turn the engine light off?
2023 EQE 500 SUV electric and 2024 Jaguar F-PACE SVR 5.0L
It's possible for a thermostat to fail closed but most ones made the last couple decades are designed to fail open. So you probably have a code for temp being too low not too high.
Thanks @Crito I don't believe the dealer got an error code and the dash temp gauge is now running one notch hotter than before but still running around 90-100 on its scale. When I look at the engine data, the temp looks pretty normal. If it failed open, it should be running cooler than what it was before and that is not the case. They were not able to provide me with any report or information and didn't charge me, but did say it would cost $2,200 to replace the thermostat if I wanted to do that.
Thanks @Crito I don't believe the dealer got an error code and the dash temp gauge is now running one notch hotter than before but still running around 90-100 on its scale. When I look at the engine data, the temp looks pretty normal. If it failed open, it should be running cooler than what it was before and that is not the case. They were not able to provide me with any report or information and didn't charge me, but did say it would cost $2,200 to replace the thermostat if I wanted to do that.
Have someone read the codes (if the dealer did not reset them) and post them here so we can determine why the check engine light was illuminated.
There is now way it would cost you $2000 to change your thermostat on your C300. I just changed my thermostat on my v6 Turbo and it cost my $900 including parts and fluid.
Also, I have MBII which told me that my thermostat has failed and I could see it as my car always runs around 90 but in the winter it would fall to 55-60 and at a light it would go back up to 75 but never higher unless the day was warm, then it would only get to 90 after sitting a light and it would sit around 85.
If you are in are in a warmer climate most of the time, your car will always run warmer and never fool down fast enough to not cause engine damage.
Thanks @alynch will do. the following are photos of dash This is after driving for a little while. Stabilised at this temp or a couple higher if sport+ This is as hot as the temp gauge ever goes. It use to run one notch colder.
Thanks everyone for your responses. I took it to a local independent MB mechanic who put it on both the quick and detailed diag testing and has confirmed the temp sensor on the thermostat has gone and the whole component needs replacing. $1500 (MB quoted $2200) as need to removed inlet manifold and a lot of other components to get to it. Good news is, I have found a great place for servicing moving forward. If anyone in Melbourne is looking for a great passionate MB mechanic (22 years exp working for MB) before he tired of the modern apprentices and ways of doing business, hit me up with a message.
03-05-2024, 01:11 AM
Engine light - dealer thinks thermostat
Thermostat confirmed
