After re-arranging the bedroom furniture yesterday, I went up to Walmart for some things. Came out of Walmart, started up the TB, and I knew right away that she wasn't happy about something! The idle was quite rough, and then the MIL came on. Not only did it come on, but it was flashing! I knew that wasn't good! I drove home and hooked up the code reader: P0302, misfire cylinder #2.
I know that the two most common causes of of a P03** code are bad plugs and bad coils. It was too late and too dark to do anything about it last night, but today after church I swapped coils between cylinders 1 and 2. I figured that if I now had a P0301 code that it was most probably the coil. If I still had the P0302 code I would replace the spark plug and see if the ode went away. If I now got a P0300 code (misfires multiple cylinders) it was most likely that the spark plug went bad and subsequently took out the coil. I cleared the codes and went for a drive. Within a mile the MIL came back on and was flashing. Came home, hooked up the code reader, and read the codes: P0300.
Off to O'Reilly's I went! I bought two AC Delco 41-103 iridium plugs and a Standard Ignition Parts coil, cost me $97 and change. I only bought two plugs at the moment due to budgetary constraints. I'll buy 4 more on Friday, to take advantage of the rebate offer going on on those plugs (buy 4, get a $3 per plug gift card rebate. I know O'reilly's and Autozone both have this, so I'm guessing it's an AC Delco sponsored promotion.)
Came home, removed the old coil from cylinder #1 and set it FAR off to the side, cause it ain't going back on! Pulled the coil off cylinder #2 as well. Changed the plugs on cylinders #1 and 2, put the old coil back on cylinder #1 where it came from, and put the new coil on #2. Cleared the code again, and went for a drive. No more MIL! Took the TB about 20 miles down I-80, ran like she was brand new!
Next Saturday I'll replace the other 4 plugs, because the two that I took out were Autolite AP 5263 plugs. These are not even iridium plugs, they are platinum plugs! I have read numerous accounts across multiple forums about how picky these 4.2L engines are about their plugs, and if it doesn't have the correct plugs that's something I want to get taken care of!
I have a question I would like y'alls input on: Some folks will put a small dab of anti-seize on the threads of the plug to prevent galling or seizing in the aluminum cylinder head, while others say that doing that prevent getting an accurate torque reading when tightening the plugs, plus it can change the heat range of the plug. When I was in auto mechanics class in high school, the teacher said it wasn't a good idea to put anti-seize on spark plug threads, but that was back when most cylinder heads were cast iron. I can see why a small amount would be applied to plugs in an engine with an aluminum head, though.
What say ye?
The plugs that I removed show evidence of anti-seize, but I did not put any on the plugs when I installed them. When I install the other 4 plugs next weekend, should I put anti-seize on them? If I do, I'll go back and put it on the other two plugs as well.
I'm just glad I got 'er fixed!