Hi

I have a 2001 2.2 litre camry. When the engine is cold below operating temp, my car takes off normally through the gears to I think 2nd or 3rd? However when I am coasting down the hill from my home at around 50 to 60 kmph, it briefly drops in revs on its own as if it wants to change up a gear however it doesn't do so. The revs return to normal and the car returns to the gear it was in instea of going up a gear.
Once the car has reached a certain temp after a few minutes driving it will change gears correctly. Other than this I think the transmission changes correctly with out slipping however it seems to be very slow reversing.
Also at higher speeds after a long day of city driving it seems that the car is intermittently lowering revs when coasting as if the car is going in and out of overdrive a lot. It's very difficult to tell if that is what it is doing or if there is an engine miss or something. This is at around 80 or 90 kmph. It kind of feels like an odd rumble and has nothing to do with the road or tyres etc. Just seems like a subtle change in power occasionally kind of like the air conditioner is cutting in and out a lot. But it happens whether the ac is on or not. Besides this the car seems to drive ok I am just concerned about ending up stranded. It changes through gears normally and kicks back when needed. Anyway any ideas about these issues woukd be appreciated. Thankyou!

Kaybee