I have a 2005 Lexus RX330 with 32K miles. It is my wife's car so I rarely drive it. When I did drive it yesterday I noticed it "chugged" about three or four times when starting but started okay, so I drove it yesterday and today and the same "chugging" happened each time I started. It has a battery from Autozone so I took it there and had them test the battery/altenator. They said the battery passed but the alternator failed. I brought it home and tested the battery voltage (it was 12.7 V) and tested the voltage with the car idling (it was 15.5 V) so that confused me. That should be around 14 V (I think???) so why would it be that high and also that did not seem to indicate an alternator problem (just guessing). I read somewhere where I should turn the lights on and see if they dim when starting. I did this and the lights dimmed but the engine "chugged" and started. Could the problem be in the starter or starter solenoid? Any thoughts?