Today I noticed that my 01TT starter cranked a little slower than usual - I then ran an errand, then pushed the car up my favorite hill. Up this hill, I noticed that it was not at its usual power level. Upon returning home (up another hill), I lost power (cut out -popping noises) and barely nursed it home (idled ok). Upon starting and driving again, it quickly deteriorated to where I nursed it back to the garage, then noticed a slightly rough idle. This turned into a major miss within 15 seconds and I shut the engine off. When I first started the car, I noted that I had 13.8 volts, now with the ignition on (engine off) I checked for 12 volts, and found 11.5-11.75, which could be pulled down to 11 with lights on. I then tried to start again, and experienced the clicking starter solenoid.

Help! My questions are these:

1/ How can a bad battery affect driveability like this where it rapidly deteriorated to undrivable?? - every other car I've had would just use the 13.8 volts from the alternator.

2/ What will I have to do when I install a new battery - radio code, turn ignition on a listen for "clicks" of E-Throttle?, etc.

3/ Anyone had this failure mode with a bad battery - I have it on a charger (out of car) and it pulled over 10 amps, currently at 6-7 after a few hours.

4/ Based on my symptoms, could it be something else on top of the bad battery?

Thanks for the help

Bond

 

Look on Rennlist. This subject was broached several days ago and one member gave a pretty good explanation of how the battery affects performance. Good luck.