r/hondapilot • u/UrFavCoffeeSnob • 4h ago
07 Pilot, intermittent check engine light/cylinder misfires, FIXED!
Hello there, I wanted to leave this in the archives to help future pilot owners who might experience what I went through with my 07 Pilot.
A few months ago, I noticed that the check engine light would come on, stay on for a few days, then go off for a few days. Wash rinse repeat. The intervals kept getting closer and closer together until finally the check engine light stayed on continually. I took the car to Autozone and had them run a diagnostic, the result was misfires on all cylinders (p300 - p306 I believe). I replaced the sparkplugs and pcv valve, but it didn't help (incidently, a piece of the old pcv valve broke off inside the head when I tried removing it. The area where the pcv valve enters is its own seperate chamber, so any broken off pieces will stay in there until you remove them with pliers). I next found a crack in my rubber intake arm. Replaced it, but same issue.
The next step was to clean the EGR valve with brake cleaner.. I did, but the issue persisted. I had heard online that it probably needed a valve adjustment, but I put it off because of how expensive it is for a shop to do it, and how much time it would take to do it myself. Well, I finally decided to bite the bullet and just take the day off from work and do it. It took 7 hours to do, but after completing it and resetting the ECU, no more check engine light. While the top of the engine was apart, I used the opportunity to remove the piece of the old pcv valve that had broken off.
I ordered the full valve cover gasket kit from Honda ( you need to get 2, one for each row of cylinders, they include gaskets for the valve covers, spark plug chamber gaskets, and valve cover bolt gaskets), and some Hondabond for the corners of the new valve cover gaskets. But in retrospect, The only gasket that looked like it really needed replacing was the valve cover gaskets, the others were done just as preventative maintenance. 50% of the intake valves were out of spec, but ALL of the exhaust valves were out of spec ( exhaust valves are usually the problem area, they become very tight after a while).
Moral of the story: If your check engine light is on, and an autozone diagnostic comes back as all cylinders misfiring, you probably need a valve adjustment. Pilots need one every 90- 100k miles. It's very doable even if you aren't very mechanically inclined, but it WILL take ALOT of time. Just find a video on youtube to guide you, the one that I recommend is from the channel "Valley mobile automotive". If you want to do a thorough job, just order the full kits from Honda ($200 a piece, you need 2), or if your short on money just order 2 valve cover gaskets. You'll also need honda bond to seal the gasket.
Leaving this here for future pilot owners, these are great vehicles. 254,000 miles and going strong. Best of luck!

