brus brother Posted July 11, 2020 Share Posted July 11, 2020 (edited) 08 OB with 105K. I get P0303 when car has been sitting in garage and humidity is off the charts. Runs like crap then after sitting out in the sun (drying out) engine smooths out and code disappears after drive cycles. Wires or coil? Edited July 11, 2020 by brus brother Quote Link to comment Share on other sites More sharing options...
ocei77 Posted July 11, 2020 Share Posted July 11, 2020 Probably wire, Switch to another cylinder, clear code and see if code returns on the new cylinder. O. 1 Quote Link to comment Share on other sites More sharing options...
brus brother Posted July 11, 2020 Author Share Posted July 11, 2020 (edited) ok got 1 and 3 off. 3 had moisture down around the wire tube. Dried it off and put back together. Is there anything I can spray/lather on the boots to prevent the moisture from seeping down along the tube? Edited July 11, 2020 by brus brother Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 11, 2020 Share Posted July 11, 2020 DOW Corning 111 valve sealant. GD Quote Link to comment Share on other sites More sharing options...
brus brother Posted July 11, 2020 Author Share Posted July 11, 2020 (edited) thanks for the tip GD. I assume you apply it to the outer lip of the plug wire as shown below at the widest point of contour? Or do you slather it over everything from the front bumper back to the A pillar;-)? Edited July 12, 2020 by brus brother 2 Quote Link to comment Share on other sites More sharing options...
GeneralDisorder Posted July 12, 2020 Share Posted July 12, 2020 Yes. It's also nice on toast. GD 2 Quote Link to comment Share on other sites More sharing options...
brus brother Posted July 14, 2020 Author Share Posted July 14, 2020 spoke too soon. misfire and code returned. pulled plug and sure enough, 'twas oil on the tube and not condensation. will need to change VC gaskets and grommets? Quote Link to comment Share on other sites More sharing options...
brus brother Posted June 6, 2021 Author Share Posted June 6, 2021 (edited) P0303 is Baaaack! I swapped cylinder 1 and 3 wires a few months ago but the code doesn't follow the wires. Still showing cylinder #3. Was pretty cool and rainy around here for a few days then popped over 90 today. The garage was dripping with condensation. Ran rough until I opened the hood outdoors and let the humidity settle down. Coil? If coil it is, any opinions on decent aftermarket or any ole one'll do? Edited June 6, 2021 by brus brother Quote Link to comment Share on other sites More sharing options...
heartless Posted June 6, 2021 Share Posted June 6, 2021 try running it when dark out.. pop the hood, start the car, and look for arcing. can be done at anytime... humid or not.. just use a spay bottle to mist moisture over the coil area.. if it is the coil, you will see it sometimes the arcing is bad enough, it doesn't even need to be dark out lol this was on my 95 Legacy... https://youtu.be/jMNfF-vcUDs 1 Quote Link to comment Share on other sites More sharing options...
jonathan909 Posted June 6, 2021 Share Posted June 6, 2021 (edited) Any silicone dielectric goo (that's a term of art) will do, and use it liberally at both ends of the wire after cleaning everthing up - once the arc starts, it creates carbon tracks that it likes to continue to follow, especially on the surface of the (ceramic) plug insulator. If it still acts flaky and the fault sticks with the cylinder, you may have a hairline crack in the insulator, so you're just going to have to replace the plug. Edited June 6, 2021 by jonathan909 1 Quote Link to comment Share on other sites More sharing options...
jonathan909 Posted June 6, 2021 Share Posted June 6, 2021 1 hour ago, heartless said: this was on my 95 Legacy... https://youtu.be/jMNfF-vcUDs Ooooo! Pretty light show! 2 1 Quote Link to comment Share on other sites More sharing options...
heartless Posted June 6, 2021 Share Posted June 6, 2021 1 hour ago, jonathan909 said: Ooooo! Pretty light show! yes, it definitely was and in broad daylight, too! LOL just goes to show how bad it really was Quote Link to comment Share on other sites More sharing options...
brus brother Posted June 7, 2021 Author Share Posted June 7, 2021 Wow, that video would seem to indicate that you might get codes reading adjacent cylinders. any thoughts of oem or aftermarket (specify brand if you like) for a replacement? as I said I have already swapped wires and the code fault stayed with the cylinder so the wires would seem to be OK. Quote Link to comment Share on other sites More sharing options...
heartless Posted June 7, 2021 Share Posted June 7, 2021 honestly, that situation is not real common, so I would go with a used OEM one matching your year, or close to it. that was what I did - grabbed the coil pak off my old 1990 Legacy and plopped it in.. no more problems and yeah, you would think it would show more than one misfire code, but it only ever threw the one cylinder, and it was always when it was damp out. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.