Thread: torque converter lock up cold

I'm not sure exactly what you're asking, but the torque converter won't lock up until the transmission gets up to a certain temp. They do this to generate some heat to bring it to an acceptable temperature earlier.

No, it's not based on engine temp, it's based on transmission temp.

the newer cars are like that since they have a temp sensor in them. iirc, the temp has to reach 68 degrees. the older non-electronic trannys went into lockup at the programed engine temp. my 94 Z24 locked up when coolant temp reached 135 degrees. leave your thermostat in, although, i switch off--180 summer, 195 winter.

Originally Posted by torq455

the newer cars are like that since they have a temp sensor in them. iirc, the temp has to reach 68 degrees. the older non-electronic trannys went into lockup at the programed engine temp. my 94 Z24 locked up when coolant temp reached 135 degrees. leave your thermostat in, although, i switch off--180 summer, 195 winter.

In my 97 GTP, the torque converter won't lock up until the temp reaches 77°F. I have watched this many, many times with my scanner. Might be different with different cars. But that is what mine is.

Yeah there is a lot of variation on almost every year as to when it applies. I dug up some info in a GM service manual on this earlier in the year and is in a thread on here somewhere. This particular year, around 2001 or so, said TCC wouldnt engage until the engine temp was over 130 or 160 and it sounded high to me as I know some of the earlier years would allow lockup at engine temps over 120. Every year seems to use a different strategy for this and the purpose is to let the trans and engine warm up faster by allowing the rpms to stay higher. In any case, yes it is normal for lockup to not engage for a few minutes when you start off cold.