Hot engine - initial drive off high RPM
06-06-2018, 04:50 PM
#1
Member
Thread Starter
Hot engine - initial drive off high RPM
So with summer pretty much officially here (hitting low to mid 90's) have gone from cold start troubles to hot start weirdness (or normal operation). Today went to a work function after work where my car was parked for ~2-2.5 hours in the hot sun in an asphalt parking lot.
Car was absolutely roasting when I got back in it and probably just started cooling off from the drive to the venue from earlier. So besides for the cooling fans going into jet engine mode from hitting max cool I noticed the car was holding gears way longer than needed at parking lot speeds. While I spent a minute or two getting out of the parking lot the trans was letting the engine get up to 2500-3000 RPM before shifting and this was without any type of load, basically just slowly cruising through a parking lot. I have noticed this before on some hot starts previously but it was very evident today as my music was taking a bit to boot up so was driving around in silence.
Is this just a function of the car trying to get the hot coolant pumped out of the block or should I be concerned? Trans shifting goes back to normal after doing this for first 1-2 takeoffs, never seems to run hot and cooling fans don't seem to be an issue.
Car was absolutely roasting when I got back in it and probably just started cooling off from the drive to the venue from earlier. So besides for the cooling fans going into jet engine mode from hitting max cool I noticed the car was holding gears way longer than needed at parking lot speeds. While I spent a minute or two getting out of the parking lot the trans was letting the engine get up to 2500-3000 RPM before shifting and this was without any type of load, basically just slowly cruising through a parking lot. I have noticed this before on some hot starts previously but it was very evident today as my music was taking a bit to boot up so was driving around in silence.
Is this just a function of the car trying to get the hot coolant pumped out of the block or should I be concerned? Trans shifting goes back to normal after doing this for first 1-2 takeoffs, never seems to run hot and cooling fans don't seem to be an issue.
06-06-2018, 05:25 PM
#2
Member
Mine always does this when in "S" mode for tranny. Always assumed it was normal as my W202 does it no matter what and benz said it was to help warm the engine to proper operating temp.
Apologize if I steer you wrong but seems normal to me, granted I've always been poor and never had a higher end Benz.
Apologize if I steer you wrong but seems normal to me, granted I've always been poor and never had a higher end Benz.
06-07-2018, 12:00 PM
#3
Junior Member
I'm also experiencing the same situation.
however I found that if you have not turned on car A/C,
The first shift would be normal.
Or after A/C on and stay idle for 5min or more, first shift would also normal.
However after engine started and A/C on then drive,
first gear will pull up to 2500~3500rpm before shift to next gear.
If you hold the gas paddle to 2000rpm, it takes much longer to shift to next gear.
It looks normal, nothing bad and no errors so far,
Just feel a bit weird.
however I found that if you have not turned on car A/C,
The first shift would be normal.
Or after A/C on and stay idle for 5min or more, first shift would also normal.
However after engine started and A/C on then drive,
first gear will pull up to 2500~3500rpm before shift to next gear.
If you hold the gas paddle to 2000rpm, it takes much longer to shift to next gear.
It looks normal, nothing bad and no errors so far,
Just feel a bit weird.
