Just purchased an 05 LS430 with 130k miles and on my way home the engine light and traction control light came on. Got home and discovered to be P0307 (cylinder 7 misfire). I switched the spark plug and coil on cylinders 5 and 7, cleared the code, and the same P0307 code came back up. So issue could be electrical going to the cylinder 7 coil or low compression (I HOPE NOT) in cylinder 7. I couldn't quite find a forum on this issue or the solution to it. Does anyone have any advice? I will be buying a compression tester here shortly, however, I do not have many tools or a garage anymore so I am limited. Thanks!
Most likely a broken wire in the coil connector. A new pigtail is cheap and easy to install.
This wire was broken internally and caused the same misfire code.
Most likely a broken wire in the coil connector. A new pigtail is cheap and easy to install.
This wire was broken internally and caused the same misfire code.
Thanks for the reply. I used a volt meter and found no discontinuities. I wish that was the issue...
Where did you test from? Did you front probe the connector while wiggling/pulling the wires? How did the spark plugs look in the 2 cylinders?
I did not wiggle wires but that’s a good point. I probed the actual connection and probed a couple inches up the wire from the connection. The spark plugs looked identical. Both looked good. Also, it’s important to note I got about 28 mpg on my 3 hour ride home and it ran fine as far as I could tell.
That wire I posted above also passed a continuity check. It passed all the tests outlined in the factory service manual. Many others have had this same issue and a new pigtail fixed it. Driving with a misfire is not good for your catalytic converter.
Cut it wherever it's easiest to splice. The new pigtail I used had about 5in of wire on it. I just got cheap ones online and they work fine but the wire colors won't match.
Cut it wherever it's easiest to splice. The new pigtail I used had about 5in of wire on it. I just got cheap ones online and they work fine but the wire colors won't match.
Just replaced and it was not the issue unfortunately…
Alright valve is cracked in that cylinder. Mechanic quote was near 6k to rebuild heads and timing belt so I’m doing myself.
Near 1000 in gaskets, seals, timing belt kit. I’m going to replace all 4 valves in that cylinder, lap all valves, new stem seals, and resurface the bottom of the heads on sand paper and sheet of glass. If valve guides have play, I’ll send heads off to be professionally rebuilt.
My other option is to buy a low mileage engine for 2000 plus a $300 timing belt kit. My car has 130k miles. I have access to a cheap garage on base that has a car lift, engine hoist etc. Has anyone done either of these jobs and want to weigh in your opinion? Could swapping an engine be easier and probably better?
