CapriceV8
06-04-2013, 05:35 AM
The transmission in my V8 Caprice with 6L80E has a problem, symtoms as follows:
When cold, everything seems fine (edit: except for the slightly rough shifts from 2nd to 3rd, mentioned below)
When the transmission sump temperature reaches about 266F, it sticks in 2nd and, I think, 3rd gears. Sometimes it will shift, but only if I rev it much higher than I normally would have to. Other times it will not shift at all. (tried manual mode) It drives normally when stuck in gear - no flare that I can detect etc.
Sometimes, before I notice any problems when driving normally (in D), I will try manually shifting to 2nd or 3rd when the car is stationary. This normally works fine, but when the temp is approaching 266, it will refuse to shift out of 1st gear. However, if I then take off in D normally, it does seem to drive normally. So, this refusal to shift in manual mode seems to be a sign that problems are about to start.
It will sometimes throw error code P0716 ("Input/Turbine Speed Sensor Circuit Range/Performance"). It only ever throws this error when the car is stationary. (and it will shift to 3rd gear, which I understand means it is in limp-home mode).
Now, I've been doing something which I fear may have contributed to the problem. In order to reproduce an engine pinging problem, I have been revving the engine a bit (typically a bit over 1000rpm) in gear, holding the car with the brakes. (it didn't ping when revved in neutral) It never reported an error when I did this, but perhaps it still caused some damage. :(
If the transmission does overheat, does it report an error?
History:
Vehicle has about 155,000mi on the clock.
The transmission was rebuilt about 31000mi/12 months ago, including a replacement of the transmission computer. (they told me it was just a bad solenoid, but that the solenoids can't be replaced individually, so they have to change the entire computer - unlike the old days)
A day or so after the rebuild, that same error code (P0716) occurred, again when stationary, in D. The mechanic replaced the speed sensor, and that error never occurred again until recently. I didn't look at the temperature when this occurred, but I remember that it was after a fairly long drive on the freeway without stopping. Note that another very mild problem did (and still does) occur very intermittently though - shifts from 2nd to 3rd would be a bit rough, when taking off gently.
Current work done to date:
The same transmission specliast that did the rebuild has replaced the same speed sensor for a SECOND time. I have not tested it yet, but I will be amazed if this fixes the problem. (will be testing it out shortly) (the rebuild is out of warranty btw)
Any assistance much appreciated.
Greg.
When cold, everything seems fine (edit: except for the slightly rough shifts from 2nd to 3rd, mentioned below)
When the transmission sump temperature reaches about 266F, it sticks in 2nd and, I think, 3rd gears. Sometimes it will shift, but only if I rev it much higher than I normally would have to. Other times it will not shift at all. (tried manual mode) It drives normally when stuck in gear - no flare that I can detect etc.
Sometimes, before I notice any problems when driving normally (in D), I will try manually shifting to 2nd or 3rd when the car is stationary. This normally works fine, but when the temp is approaching 266, it will refuse to shift out of 1st gear. However, if I then take off in D normally, it does seem to drive normally. So, this refusal to shift in manual mode seems to be a sign that problems are about to start.
It will sometimes throw error code P0716 ("Input/Turbine Speed Sensor Circuit Range/Performance"). It only ever throws this error when the car is stationary. (and it will shift to 3rd gear, which I understand means it is in limp-home mode).
Now, I've been doing something which I fear may have contributed to the problem. In order to reproduce an engine pinging problem, I have been revving the engine a bit (typically a bit over 1000rpm) in gear, holding the car with the brakes. (it didn't ping when revved in neutral) It never reported an error when I did this, but perhaps it still caused some damage. :(
If the transmission does overheat, does it report an error?
History:
Vehicle has about 155,000mi on the clock.
The transmission was rebuilt about 31000mi/12 months ago, including a replacement of the transmission computer. (they told me it was just a bad solenoid, but that the solenoids can't be replaced individually, so they have to change the entire computer - unlike the old days)
A day or so after the rebuild, that same error code (P0716) occurred, again when stationary, in D. The mechanic replaced the speed sensor, and that error never occurred again until recently. I didn't look at the temperature when this occurred, but I remember that it was after a fairly long drive on the freeway without stopping. Note that another very mild problem did (and still does) occur very intermittently though - shifts from 2nd to 3rd would be a bit rough, when taking off gently.
Current work done to date:
The same transmission specliast that did the rebuild has replaced the same speed sensor for a SECOND time. I have not tested it yet, but I will be amazed if this fixes the problem. (will be testing it out shortly) (the rebuild is out of warranty btw)
Any assistance much appreciated.
Greg.