SuperDesi
November 6th, 2006, 02:09 PM
Though I haven't been here for a while (the TC was running fine), this was the first place I returned to when my relative's '03 gave a CEL on Saturday. Initially I couldn't detect a driveability problem but noticed that while stopped at light, a slight rough idle could be felt (one thing I love about these cars is that when they run right they are as smooth as silk). Sometimes the CEL would start flashing which I knew was really bad.
So Sunday I connected my scanner and pulled 0300, 0302, 0308, 0316. I also noticed that the B1S2 O2 fuel trim, B2S2 O2 fuel trim & B2S2 O2 output voltage was not in range (too high), so I thought perhaps an O2 sensor was bad and causing the misfire issue. I was surprised that I had misfires in 2 cylinders at the same time (I had done a major tune-up only 5K miles ago). So to begin my diagnosis I removed the coil and plugs from those cylinders and they looked fine and the resistance values of the coils were in spec. I cleaned off the plugs (the gap was fine) and reinstalled everything. Now the scanner only showed 0308, 0316. So cylinder 2 must have corrected itself. That is when I logged on to LO and read that most misfires on the late model TC's pointed to the COP.
So I went back to the car and decided to swap the coil from cylinder 8 with the (good) cylinder 1. Another scan with my trusty computer now pointed the misfire in cylinder 1 which confirmed that the coil was bad. Now I would've replaced that coil myself but my impatient relative didn't want to wait a few days for the parts, so he had me take the car to his mechanic (open 24 hours). I brought the car in and the mechanic started his own diagnosis with his scanner. He started spraying carb cleaner around the intake, unpluggin the coils one by one while engine running, removed a few plugs, and started telling me it could be a bad injector. He took out the bad #1 cylinder coil, tested it, and was going to reinsert it when I got tired of his diagnosis and told him to just replace that coil. He said how would I know and I told him to "please just change that coil, its defective". He thankfully listened to me and the problem was resolved for only $49 (the cost of the coil).
Sorry for posting this long thread but I just wanted to thank all the good bunch of individuals we have on this forum like Dereck, V8_Dave (to mention a few). Even though the resistance of the coils were in spec, they could still be defective (thanks to a post by V8_Dave). I had made a better diagnosis that this mechanic who BTW only repairs Lincolns and Crown Vics.
So Sunday I connected my scanner and pulled 0300, 0302, 0308, 0316. I also noticed that the B1S2 O2 fuel trim, B2S2 O2 fuel trim & B2S2 O2 output voltage was not in range (too high), so I thought perhaps an O2 sensor was bad and causing the misfire issue. I was surprised that I had misfires in 2 cylinders at the same time (I had done a major tune-up only 5K miles ago). So to begin my diagnosis I removed the coil and plugs from those cylinders and they looked fine and the resistance values of the coils were in spec. I cleaned off the plugs (the gap was fine) and reinstalled everything. Now the scanner only showed 0308, 0316. So cylinder 2 must have corrected itself. That is when I logged on to LO and read that most misfires on the late model TC's pointed to the COP.
So I went back to the car and decided to swap the coil from cylinder 8 with the (good) cylinder 1. Another scan with my trusty computer now pointed the misfire in cylinder 1 which confirmed that the coil was bad. Now I would've replaced that coil myself but my impatient relative didn't want to wait a few days for the parts, so he had me take the car to his mechanic (open 24 hours). I brought the car in and the mechanic started his own diagnosis with his scanner. He started spraying carb cleaner around the intake, unpluggin the coils one by one while engine running, removed a few plugs, and started telling me it could be a bad injector. He took out the bad #1 cylinder coil, tested it, and was going to reinsert it when I got tired of his diagnosis and told him to just replace that coil. He said how would I know and I told him to "please just change that coil, its defective". He thankfully listened to me and the problem was resolved for only $49 (the cost of the coil).
Sorry for posting this long thread but I just wanted to thank all the good bunch of individuals we have on this forum like Dereck, V8_Dave (to mention a few). Even though the resistance of the coils were in spec, they could still be defective (thanks to a post by V8_Dave). I had made a better diagnosis that this mechanic who BTW only repairs Lincolns and Crown Vics.