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Hello all. New here and have just recently purchased a C63s (traded my C450).
In the C450 I always drove around in S+ so of course after break-in I'm doing the same with the C63s. I noticed that the gear box temp shoots up really quick. The highest I've seen it is 230F while driving in low speed traffic (15-30mph) but average is 204-208.
I also notice that the temps will spike when I first drive, fan sounds like a Dyson, temps go down, then they never get that high again. It's almost like the trans cooling system is reactive at first then proactive after the first bit.
Even at idle if I'm in "C" and then bump the mode to S+, the temp goes up a few degrees. Logic tells me that the line pressure shoots up really high in order to give the driver a Dual clutch feel but still be an automatic.
Hello all. New here and have just recently purchased a C63s (traded my C450).
In the C450 I always drove around in S+ so of course after break-in I'm doing the same with the C63s. I noticed that the gear box temp shoots up really quick. The highest I've seen it is 230F while driving in low speed traffic (15-30mph) but average is 204-208.
I also notice that the temps will spike when I first drive, fan sounds like a Dyson, temps go down, then they never get that high again. It's almost like the trans cooling system is reactive at first then proactive after the first bit.
Even at idle if I'm in "C" and then bump the mode to S+, the temp goes up a few degrees. Logic tells me that the line pressure shoots up really high in order to give the driver a Dual clutch feel but still be an automatic.
Anyone have similar experiences?
i don't think I've ever seen my temps at 230. That seems extremely high to me. But I guess it depends on the avg temp of where you live. We rarely see anything about 80 in WA and that's in the rare summer months.
i don't think I've ever seen my temps at 230. That seems extremely high to me. But I guess it depends on the avg temp of where you live. We rarely see anything about 80 in WA and that's in the rare summer months.
Highest ive seen is ~210
Yeah that's what I figured thanks. It was a 45 degree day in Georgia when this happened.
The highest transmission temperature I've seen was around 195F-200F, and that was in a C63S Coupe at the AMG Driving Academy while driving around COTA.
On my personal car, in Houston summer heat (can be 100F+), the highest I've seen is maybe 187F after driving the car harder than normal. The temperature usually stabilizes around 178F-180F under normal driving.
If you are seeing 230F for the transmission, something is definitely wrong with your car.
The highest transmission temperature I've seen was around 195F-200F, and that was in a C63S Coupe at the AMG Driving Academy while driving around COTA.
On my personal car, in Houston summer heat (can be 100F+), the highest I've seen is maybe 187F after driving the car harder than normal. The temperature usually stabilizes around 178F-180F under normal driving.
If you are seeing 230F for the transmission, something is definitely wrong with your car.
100+ degrees....which driving mode? Just curious so I can give my dealership some other examples.
100+ degrees....which driving mode? Just curious so I can give my dealership some other examples.
I'm 99.9% of the time in Individual Mode with the engine/trans set to Race.
Are you sure you are looking at the transmission temperature and not the engine oil temperature? The transmission is the bottom of the two temps shown on the AMG screen. What you are describing above sounds very similar to what I've seen my engine oil temperature do. Highest I've seen that go is 224F, but it'll stabilize about 215F during normal summer driving.
Engine oil temps as high as 224F for me, with transmission temp as high as 205F. That's on a hot 90F+ day in slow stop and go traffic. Incidentally when my original piggyback failed the first time due to heat soak. I mode but basically Sport+ (Comfort suspension).
I'm 99.9% of the time in Individual Mode with the engine/trans set to Race.
Are you sure you are looking at the transmission temperature and not the engine oil temperature? The transmission is the bottom of the two temps shown on the AMG screen. What you are describing above sounds very similar to what I've seen my engine oil temperature do. Highest I've seen that go is 224F, but it'll stabilize about 215F during normal summer driving.
Yes it's the bottom figure on the AMG screen (thermometer with a gear). Before my last Mercedes I drove a heavily modded Evo X so I'm fairly familiar with gearbox and diff oils
What's odd is that my oil temps...are always just barely above 200F. Wouldn't that be hilarious if both sensors terminated into the same device but were swapped in position
Yes it's the bottom figure on the AMG screen (thermometer with a gear). Before my last Mercedes I drove a heavily modded Evo X so I'm fairly familiar with gearbox and diff oils
What's odd is that my oil temps...are always just barely above 200F. Wouldn't that be hilarious if both sensors terminated into the same device but were swapped in position
Normal driving in S+ I get 183 F on the trans and 213 F on the engine.
pushing hard bumps up 10 -15 deg.
Yours is way high
The neC63 has a transmission fluid temp. Sensor? Impressive!
What do they expect that you do with that information? If high temps are a concern, a cooler might be of more use than a temp. Sensor.
Thanks for all the replies, the feedback will help me explain my case.
For all that are curious, here she is after pulling out of a gas station and driving about an 1/8 mile...starting at about 205 F. I've got an appointment to bring the car in and hopefully they'll figure it out. I'm certain that if ignored that number will be way higher when the summer finally gets here.
About 55 degrees last night in Houston after cold start up in Sport mode it took my trans about 8 mins to get up out of blue temp to 125 degrees. Once the engine and trans were warm and opening it up on a 30 min drive the engine maxed at 194 and trans at 176.
So a corrective action has been applied, the expansion tank for the intercooler system was bone dry. The dealer bled and topped off the system which got the temps back down to normal. The night before I added a little coolant which made a huge difference on the trip to the dealer. Of course I couldn't find the right coolant so 50/50 autozone had to do, I was more concerned about temp control than coolant quallity at that point.
They were having issues with their diagnostic machine so I couldn't get a better explanation other vthan the fact that the tank was dry. There was never a smell of burnt coolant or coolant on my garage floor. Either the factory did not fill/bleed the system correctly or the car burnt it off for some reason.
I'll need to bring it back when their diagnostic machine is "working" for a deeper dive.
Last edited by mjones800; Feb 19, 2017 at 07:55 AM.
So a corrective action has been applied, the expansion tank for the intercooler system was bone dry. The dealer bled and topped off the system which got the temps back down to normal. The night before I added a little coolant which made a huge difference on the trip to the dealer. Of course I couldn't find the right coolant so 50/50 autozone had to do, I was more concerned about temp control than coolant quallity at that point.
They were having issues with their diagnostic machine so I couldn't get a better explanation other vthan the fact that the tank was dry. There was never a smell of burnt coolant or coolant on my garage floor. Either the factory did not fill/bleed the system correctly or the car burnt it off for some reason.
I'll need to bring it back when their diagnostic machine is "working" for a deeper dive.
So a corrective action has been applied, the expansion tank for the intercooler system was bone dry. The dealer bled and topped off the system which got the temps back down to normal. The night before I added a little coolant which made a huge difference on the trip to the dealer. Of course I couldn't find the right coolant so 50/50 autozone had to do, I was more concerned about temp control than coolant quallity at that point.
They were having issues with their diagnostic machine so I couldn't get a better explanation other vthan the fact that the tank was dry. There was never a smell of burnt coolant or coolant on my garage floor. Either the factory did not fill/bleed the system correctly or the car burnt it off for some reason.
I'll need to bring it back when their diagnostic machine is "working" for a deeper dive.
I'm not too familiar with the W205s, but how does empty coolant result in wonky transmission temperature readings? The transmission should be exclusively oil-cooled, no?
I'm not too familiar with the W205s, but how does empty coolant result in wonky transmission temperature readings? The transmission should be exclusively oil-cooled, no?
On the W205's, the trans cooler is water cooled and in the same coolant circuit as the inter-coolers. So there are two expansion tanks, one for the engine coolant and another for inter-cooler and transmission. I've never seen anything like it.
Here is a diagram I pulled from a DIME racing thread...with my own annotation
Update: Brought the car back to the shop Friday for diagnosis. One of the low temp pumps failed and today the tech will have to inspect the intercoolers for leaks.
Unfortunately there was no low coolant warning for the center expansion tank and no CELs for the failed low temp coolant pump. The tech explained to me that the failure of either low temp pump will never throw a CEL, the owner will never know.
I think the same thing has happened to me - there is absolutely NOTHING in the manual I can see about topping up that centre expansion tank, and the diagram posted seems to suggest that it’s all one loop with the lower one anyway?
has anyone else been given advice to top up the central coolant tank?
Replying to my own message in the hope that this might help others.
Keep an eye on that central coolant tank that is in the middle of the engine. If it goes dry you have a problem. This does indeed feed the secondary coolant system for the turbos and gearbox. The pumps are not robust and fail frequently. It's a €250 part so not the end of the world and of course if you have warranty it should be covered.
Your gearbox oil temp will keep going up and there is no warning or shutdown - so check that reservoir every time you check your oil (which is every two weeks, right?).
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Well whatever the dealer finds out I'll be sure to post it up.
