P0305 Code (misfire code) Topic is solved

[adbalt]

Checked again and its the spark plug well directly behind the oil fill cap that was filled. The top around the cap also also had oil pooled. I will change the cap and see if that solves that as well as change the wires and plugs to see if the misfire code goes away. I will update when finished and advise if that solves the issues. Thanks for everyones help!

[E Showell]

Good practice to change the rubber seal on the oil filler cap at every or every other change.

[adbalt]

Thanks for the tip. I didn't realize the gasket came off and was replaceable.

[E Showell]

An expensive alternative is the get an IPD billet cap with special seal. The seal is supposed to last a good long time.

[adbalt]

One last question. If some of the plug wires were arcing would that indicate the distributor cap is OK or should I replace everything?

[erikv11]

Yeah, just replace the gasket, the oil cap itself is probably fine.

The problem could be just wires, just cap, or both. You can't really tell without more testing. If the cap is not Bosch I would replace it, can you wait as long as it would take for obayha's to arrive?

[adbalt]

Just wanted to give an update. Took me awhile to get back at it. I recently changed the oil filler cap and that solved the problem of the oil leaking onto the top of the plug wells. I changed the distributor cap, plugs, and wires. Although the car runs great it still sets a P0305 code. Not sure why but for now I'm going to continue to drive. Only issue other than the code being set off is a rough idle when stopped. Not sure if the code and rough idle are related. Anyway thanks for everyones help and any ideas feel free to let me know.

[rspi]

[abscate]

With a new cap rotor wires and plugs - a misfire code is a cue for a compression test on that cylinder - and the rest while you have the tools out.

[songzunhuang]

Just wanted to give an update. Took me awhile to get back at it. I recently changed the oil filler cap and that solved the problem of the oil leaking onto the top of the plug wells. I changed the distributor cap, plugs, and wires. Although the car runs great it still sets a P0305 code. Not sure why but for now I'm going to continue to drive. Only issue other than the code being set off is a rough idle when stopped. Not sure if the code and rough idle are related. Anyway thanks for everyones help and any ideas feel free to let me know.

Wondering if you were able to get this figured out. My car recently started to do the exact same ting with the same code. I changed the plug wires and checked the cap and plugs. The cap and rotor looked fine and the plug in #5 didn't look wet, but I regapped it and replaced it. A trick I tried was to swap plugs on cylinder #5 (misfiring) with a plug from another cylinder to see if the misfire moved with the cylinder, indicating a plug issue. Well, I regret to report that it didn't work. I am still getting the P0305.

I did notice damage on the wiring harness leading to plug #5. I could see the copper as the insulation had been rubbed through. I taped it up with some electrical tape, but it wasn't the problem. The code came back.

Damage to the wiring harness for the #5 injector.

Beautiful blue NGK wires. Too bad they are just going to be covered up.

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I'm scratching my head a bit. If it's a head gasket or valve issue, its gets real tricky as I don't know if I have the patience or time to do this myself. At the cost of a head re-build, I am not sure it's worth it on a 245K mile car. I'm going to have my daughter drive it a bit more and then I'll do the compression test in the near future. We will see how it goes.