I have a 95 4runner v6.
When I start the engine in the morning it takes about 12min. until the gear shifts to overdrive. I know it's too long. What can be the reason?
Is it the temp. of the engine or the gear?

 

I believe it is engine temp, you may want to check to make sure your thermostat isn't sticking open, that will make the engine take longer to warm up. With my last auto (Land Cruiser) it took about 5-6 minutes of normal driving to warm up enough for it to shift normally. As you probably know, it is designed to keep engine rpms up by moving shift points higher and locking out overdrive which will bring the engine to normal operating temps sooner. If it is just idling in the driveway to warm up it may take a little longer...

 

OD on most auto trannys won't occur until the tranny fluid reaches operating temperature. There is a thermostat or bimetallic strip inside the tranny that tells the ECU when the tranny fluid is at operating temp, then it will allow shifting into OD. To get your tranny up to operating temp sometimes take between 10 and 20 miles of driving, but that can also depend on the temperature outside. I know this is how some auto trannys work, but not sure if the yota ones operate exactly this way.

 

i secong "firemedic's" suggestion as i had it happen to me.

-f-

 

I know for a FACT that it is engine temp. Mine doesn't shift into OD until the engine reaches operating temp which is usually less than 5 minutes. I would check the thermostat. It could be sticking or it could not even have one in there.

EDIT: It'll take longer to warm up in colder conditions so that might explain the difference in time.

 

I've got a '93 v6 auto that does about the same thing. I haven't actually timed how long it takes for the o/d to start working, but it seems to be about 10 mins or so. The Toyota dealer says it's normal. It so happens that I'm in the middle of changing a water pump and timing belt, and have a new t-stat that I plan to install as well. If the trans operation changes significantly after I get everything back together I'll let you know. Lyle