Hi All

I am seeing various potential issues with my auto transmission and wanted to see if you have any ideas... [2005 MCS]

When car is level and I'm using the gas pedal, the gear shifts when accelerating are generally OK, sometimes it seems like it chooses too low a gear because revs are high when trying to accelerate quickly, but generally OK.

However when I go up or down hill the auto shifting seems to go a little off. When going up the car seems to choose a really low gear so revs are super high [40mph]. I have to try and increase speed to switch up a gear and then slow back down to get it to stick. If I put it in cruise control uphill at same speed it seems to select correct gear without issues, no high revs. I've tried various amounts of gas pedal, nothing seems to work.

Going downhill too, no gas pedal, it seems to choose too low a gear so engine braking and revs are really high. With cruise control on, problem isn't there again.

Generally car seems to like to hold onto a gear longer than I would expect so revs are high and engine sounds painful. We're talking 4-5K. It this just the "S" being a sports mode car?

 

I have not driven an auto r53 (just the 6 speed stick).....
But keep in mind the peak tourqe is 3500 rpm, and the r53 does not really "wake up" till above 4000 rpm....the motor really lacks tq in lower rpms...so the motor revs to make up...not sure from your posts what high means, but going to 5000+ in a stick is the norm....
A few thoughts....
Even though the tranny was "sealed" with "lifetime lube" it seems to behave much better with a fluid change....a few folks have had issues with the valve body on the trannys over the years...

 

Thanks ZippyNH. Interestingly the car had worse issues in the past [previous owner] and the valve body on the transmission was replaced...