Overdrive Sensor

[jmur61]

My 84 Vette changes to Overdrive at 160 degrees.
In cold wheather I have to drive it for miles until it gets hot enough to kick into overdrive at 160 degrees. What can I do to make it change to overdrive at 130 or 100 degrees? Or what is the lowest degree available without causing damage to the engine?

 

[nyernga]

Is this a 4+3 or an automatic? There are several parameters that control the overdrive on the 4+3's. IE: temp, speed........

 

[RonJ]

My 84 Vette changes to Overdrive at 160 degrees.
In cold wheather I have to drive it for miles until it gets hot enough to kick into overdrive at 160 degrees. What can I do to make it change to overdrive at 130 or 100 degrees? Or what is the lowest degree available without causing damage to the engine?

My 85 4+3 is exactly the same, no O/D until 160F. Even automatics don't let the converter lock up until the engine is warmed up. Much cooler then the 160, I guess the engine isn't too efficient and just barely into closed loop.

It doesn't take all that long to get up to the 160F in my experience. Any chance that you're having a thermostat hanging open and prolonging the warm up time???

Ron ...

 

[WhalePirot]

What can I do to make it change to overdrive at 130 or 100 degrees?

Wire in an ECM bypass, as many owners did, to bypass all of the 4+3 logic.

what is the lowest degree without causing damage to the engine?

160, I think.

As Ron said, ensure that your thermostat is operating properly, as recommended. It should not take too long, especially in that climate, to reach 160.