Overdrive wont kick in when cold?

[bimmaman]

Hey guys.

I've tried searching, but couldn't seem to find anything directly relating to this issue...

Basically, first thing in the morning on my way to work, my truck wont shift into overdrive for the first few miles. I have checked the atf levels at both hot and cold temps, and it looks fine.

Anyone else experienced this? Am I just being paranoid?

My only real concern is with it being a v6 petrol, all the extra fuel its drinking before it decides to drop into overdrive...

[Sancho]

Mine used to do that. It won't change up until it's warmed up. Not sure why, but it's supposed to do it. May be worth checking your thermostat to be sure it's not jammed open and overcooling the engine.

[sv1000spilot]

Mine used to do that. It won't change up until it's warmed up. Not sure why, but it's supposed to do it. May be worth checking your thermostat to be sure it's not jammed open and overcooling the engine.

Think it's to do with keeping the revs up to help get engine up to temp quicker.

Warm engines use less fuel than cold ones, so in theory your better off getting the heat up quicker to use less fuel.

[bimmaman]

Thanks for the swift replies

So general opinion is there is nothing to worry about? That's not so bad then.

What I don't get though, is that it hasn't always done this, so I wonder why it is doing it now?

[Apache]

Probably based on ambient temps as well as ATF / Coolant temps. In the summer, everythings already close to warm enough. This time of year, takes a bit longer. I always take it easy for the first few miles anyway, til everythings up to temp and has a good supply of warm oil.

[Sancho]

Probably based on ambient temps as well as ATF / Coolant temps. In the summer, everythings already close to warm enough. This time of year, takes a bit longer. I always take it easy for the first few miles anyway, til everythings up to temp and has a good supply of warm oil.

He's in New Zealand Andy......

As I said, check your thermostat. It may be jammed open. Mine was.

[bimmaman]

Hehe yeah, it's been pretty warm over here recently... :P

Ok, I'll check the thermostat, but engine temp seems fine - it warms up nice n quick. Heater works fine etc...

Thanks guys

[skydso]

very normal ...
It's the ECU's way of not letting you go into overdrive in order to be kind to (mainly) the crank amongst other things that still have to warm up to work as they're intended to!