C180 Gear Shift at high RPM on hot days

[zeyaraung]

Hi bros, i just changed from Jap car to 10yr old C180 facelift model. I noticed that on hot afternoons after parked in hot sun, when move off gear shifts are at higher RPM. Is that common observation?

Regardless of drive off slowly, the gear wouldn't shift till around 2.5k RPM. It becomes normal after few minutes of driving, then it shift gears at below 2k RPM. On normal days or if parked under cover, I don't have this observed. Weird.

Just wondering is there anything wrong, need to pay attention or ATF change? Thanks in advance.

[Reflection]

#1 rule when buying a used car.  If you're not sure when the basic maintenance was done, assume it wasn't done and change what needs to be changed.  Spending the $ now will save you a lot down the road.

Having said that, the transmission oil needs to be at a certain temperature in order for the car to shift properly.  RPMs may be held high to help warm up the catalytic converter, in order to keep emissions standards.  Then again, that should occur whenever the engine is started cold.  Can't say for sure if there is or isn't anything wrong with your gearbox, but a fluid change won't hurt anyway.

[zeyaraung]

On 1/18/2022 at 10:26 PM, Reflection said:

#1 rule when buying a used car.  If you're not sure when the basic maintenance was done, assume it wasn't done and change what needs to be changed.  Spending the $ now will save you a lot down the road.

Having said that, the transmission oil needs to be at a certain temperature in order for the car to shift properly.  RPMs may be held high to help warm up the catalytic converter, in order to keep emissions standards.  Then again, that should occur whenever the engine is started cold.  Can't say for sure if there is or isn't anything wrong with your gearbox, but a fluid change won't hurt anyway.

Thanks, good suggestion and i should definitely do that.