LS4 Performance - Torque Converter Problems




View Full Version : Torque Converter Problems


AlabamaGuy
10-18-2009, 12:45 PM
Ok guys, we've been chasing a problem for a few months now and I've posted about it a few times. My torque converter comes in and out of lock repeatedly while cruising. It locks up before it needs to and all kinds of crazy stuff. My tuner went in and changed all the tables to get it to quit but it's like it just ignores the tune. Lately I've been noticing what feels like the converter has loostened up. I tried stalling the car up the other day and got over 3k RPM out of it just sitting still. Is this normal? I even roll back like a manual on moderate inclines.


Vectus
10-18-2009, 01:32 PM
Ok guys, we've been chasing a problem for a few months now and I've posted about it a few times. My torque converter comes in and out of lock repeatedly while cruising. It locks up before it needs to and all kinds of crazy stuff. My tuner went in and changed all the tables to get it to quit but it's like it just ignores the tune. Lately I've been noticing what feels like the converter has loostened up. I tried stalling the car up the other day and got over 3k RPM out of it just sitting still. Is this normal? I even roll back like a manual on moderate inclines.

Mine stops at 2.5K your just might be from the tune. As for the role back, my Imp does it too and dont have any problems of the sort. So yea i think those parts are normal.

Count of Monte Carlo
10-18-2009, 03:31 PM
They normally stall that high. Sometimes mine goes to 3200 on the brake stall. Not for nothing though the converter has a special kind of logic to it that GM has been using for years. They partially lock it up, supposed to make the driveline operate even smoother, and on front drives, when you release the gas it will unlock till you get back on it. I notice that when it goes into 4 cylinder mode the converter will unlock momentarily.... otherwise with a steady load on it and steady cruise it should stay in its partial lock up, unless you are lugging the engine, then it will go to full lock up. To add to further confusion, I noticed that when I cancel the cruise with the cancel button, it seems as if it is in 4th and lock up coasting.... which is cool because the exhaust burbles:)


AlabamaGuy
10-18-2009, 03:47 PM
They normally stall that high. Sometimes mine goes to 3200 on the brake stall. Not for nothing though the converter has a special kind of logic to it that GM has been using for years. They partially lock it up, supposed to make the driveline operate even smoother, and on front drives, when you release the gas it will unlock till you get back on it. I notice that when it goes into 4 cylinder mode the converter will unlock momentarily.... otherwise with a steady load on it and steady cruise it should stay in its partial lock up, unless you are lugging the engine, then it will go to full lock up. To add to further confusion, I noticed that when I cancel the cruise with the cancel button, it seems as if it is in 4th and lock up coasting.... which is cool because the exhaust burbles:)

Mine does the same thing with the burbling lol. My problem is still that it modulates in and out of lockup. Even though we do something like set lockup only above 50 mph it'll still lock up below it. It just doesn't make sense.

TheMonteMan
10-18-2009, 07:52 PM
mine also does the roll back on inclines as well. dont know the actual stall speed though.