In either cold or very hot/humid weather, from a cold start the tranny seems sluggish for about a half mile. Sticky shifting and slow acceleration. Like it needs to clear it's throat, then everything's OK. In nice weather, no problem. Had the fuel injection pressure cleaned. Not the problem. I'm the 2nd owner and don't know if the tranny oil was ever replaced. Dealer looked at oil and said, don't touch it. Better not to disturb it. Not only did he say not to do a tranny flush, but not to change the oil at oil. What next?

Far from an expert but from what I've read, tranny fluid, especially old dirty fluid tends to thicken with age when its cold. As it heats up it thins and all is well. As for your mechanic, the advice he gave you is credible. There is evidense that changing , especially flushing old fluid can dislodge caked on fluid deposits. These deposits can lodge anywhere in the tranny and create bigger headaches.

You have to decide how bad this problem is. Can you live with it or no? If not, you could try draining a small amount of fluid to have a closer look at it's condition. If it's bad enough, try draining a quart and adding a quart, drive it a day or so, then drain and add another quart and so on till you've either noticed a change in the problem or you've changed out the full capacity. You can either loosen the drain plug on the bottom of the pan with an allen wrench or pump it out the fill tube with a pump. If you've changed all the fluid and still have the problem, you still have the filter to deal with.

Thanks for the quick reply. The tranny has 150K on it. If I try the little at a time method is there a better oil to use such as Mobil 1? My concern is that if I let it go the problem will worsen. Thoughts?

my old 92 that my brother now owns (with the 2.2 auto) has had the same problem for 4 years when it is below 20 degrees out. a local trans show said it is a normal occurance for high mileage toyota trannies. the car i am talking about, if left outside overnight will not want to shift to second and if it does it slips. once the trans is warm all is back to normal. the trans shop called it cold morning sickness and says it stems from the seals being cold and letting fluid past (internally) but once the fluid warms the seals, they seal back up and the trans starts working properly. since it sits outside it now gets a 10 minute warm up at idle before pulling off and presto no more problem. don't drive it when the problem occurs because in my brothers case the slipping will tear things up. so he "works" around it and all is good. mike