Lately it's taken a bit longer for my converter to lock but I heard that cooler temps will cause this so I wasn't too worried. But lately, if I'm crusing at 70-80mph it will just randomly unlock then lock back up in a minute or so. There's 74k miles on my tranny. Any guesses?

 

Are the front and rear tires the same height? Tires close to the same pressure? No SES light?

 

Yep, 275/40/17 all around. No SES light.

 

misfires can cause it too. do you have a cam? old plugs? bad wires?

 

I had this problem with my car a couple times. One time it was due to misfires, and the other it was due to running no thermostat in too cold of weather.

 

Yes on the cam. Plugs are new and wires SHOULD be ok.

 

Have you had your cam tuned, do you get any misfire codes?

 

Yeah I have tuning but I had my misfire SES light disabled.

 

why would you do that?

 

So it doesn't go off every time I drive the car

 

Just looking at some old posts (really old) and I found that the converter supposedly doesn't lock up until the trans temp reaches 149* F. Which also means the converter will unlock if it drops below this number, which might explain why mine now unlocks if I'm on the highway in the cooler weather. Hopefully this is the case.

 

I dont think so It has been cold as hell here in Maryland lately.... even with 30 deg morings and a trans cooler and I dont have any problems with my TC locking My TC will lock at 30 mph when in D Actually I had this problem and it was from the misfire codes... but I never got and SES light from them

 

you can disable p300 and still get misfires. it just wont set the light off. you can go in and adjust the misfire detection table to fix it if its atcually misfires thats causing it. you would probably have to atap or efi live it and see the misfires on each cyl while driving when it unlocks.

 

I know this. I just disabled the light so it wouldn't come on so often due to misfires. And I don't want to disable the misfire detection table because I still want to be able to pick up misfires on atap. I'm just wondering how true this 149* locking temp is.

 

if you're computer is still detecting missfires then that is why ur TC is unlocking. have it desensitized so just the major missfires are detected. I know this was a HORRIBLE thing I had to go thru after getting my H/C combo put on...the X1 cam even during normal driving would put out missfire codes...I went back to MTI and Let Jayson work his magic and have since had no trouble. Only thing you truly need to stay on is your Knock sensors and even I had those slightly desensitized....*shrug*...