2010 Honda Odyssey Misfire Codes

[wazzuFreddo]

Time to smog the Family Truckster and of course it decides to throw some codes.

Cylinder 1 & 3 misfire plus a general misfire code. I’m thinking new plugs all around and new coils for 1&3? :dunno

 

[TheRobSJ]

More than likely valve clearance adjustment.

 

[gixxerjeff]

This.
End thread.

 

[wazzuFreddo]

Valve adjustment seems a little extreme when I haven’t even checked the coils or plugs yet.

 

[Climber]

Check for vacuum hose leaks, they are often the cause of misfires and a much cheaper fix.

Use the cigar smoke with rubber glove over the intake trick, it's very effective for finding vacuum leaks, if they exist.

 

[TheRobSJ]

Valve adjustment seems a little extreme when I haven’t even checked the coils or plugs yet.

You know what the odds are that all of a sudden, not one...but two coil and/or plug failures hit at the same time? If it was isolated to a single cylinder and the engine was shaking and felt down on power...then ok chase plugs or a coil.

But multiple misfire codes on a high mileage (probably at least 60k) Honda V6 with no other symptoms is almost always the valve adjustment.

As a bonus, you might pick up a mile or two per gallon in efficiency after it’s done.

 

[gixxerjeff]

Valve adjustment seems a little extreme when I haven’t even checked the coils or plugs yet.

It's a Honda thing.

 

[msethhunter]

Depending on milage, I'd vote for new plugs first, and if that doesn't cure it, adjust the valves. Honda for some reason, went to solid tappets in '99, and jam nut style adjusters (60+ year old tech). Lame.

 

[wazzuFreddo]

Opened it up and I can hear the misfire. 110k on original plugs unless the previous owner changed them, which I doubt.

Going to pay my father in law’s mechanic friend to change them though since the back ones are hard to get at. What would take me all day takes him 30 minuets.

If that doesn’t clear it up, I’ll have him do the valves.

 

[gixxerjeff]

Engine vacuum will tell you all you need to know.
Got a gauge?
(it's gonna be tight valves)

 

[Cycle61]

Shit, my ex's 2002 Odyssey is somewhere aroud 300-350k and I absolutely promise she's never done the valves. I replaced one coil about five years ago. It's still on it's original timing belt to my knowledge, was just about due when we got divorced in 2008. :laughing

 

[aszrael1266]

Listen to Rob, our MDX did the same thing at like 90kish miles. I changed all the plugs reset the ECU and it came back a day or so later. Took it to the dealer and it was the valves. Its just a honda thing like he said. Also who ever designed how to remove the radiator on a MDX needs to be taking out and shot. Changed mine yesterday thinking it would be like my other cars and a quick 45 min job. Had to pull the entire front end off.

 

[fast4d]

move the suspected bad coil to see if error code follows.

100k on plugs it's time to change.

 

[TheRobSJ]

Also who ever designed how to remove the radiator on a MDX needs to be taking out and shot.

They can line up in a row with some of the NSX parts suppliers and catch the same bullet. We just announced that we’re recalling all NSXs to replace the fucking fuel tanks. I figure each one will take me at least two days to do.

 

[Sharky]

I would bet could before plugs. Swap the coils with the other “good” ones and see if the misfire moves.

I would probably defer to Rob’s diagnosis, since he retired expertise on these, but checking the coils is easier than anything else.

 

[TheRobSJ]

Opened it up and I can hear the misfire.

This is what we call a hard misfire. This makes me suspect a coil now.

Does it only shake/miss when you give it a lot of gas?

 

[JesasaurusRex]

Buy a Chevy

 

[Mike95060]

This is what we call a hard misfire. This makes me suspect a coil now.

Does it only shake/miss when you give it a lot of gas?

A coil on my Nissan went out last year. It was intermittently missing on about one out of every ten starts for a month untill it gave up the ghost completely. Shame onme for letting it go that long. It failed completely of course wayyyy out of town. Thankfully the repair shop in Quincy was reasonable.

 

[wazzuFreddo]

This is what we call a hard misfire. This makes me suspect a coil now.

Does it only shake/miss when you give it a lot of gas?

It was just idling since I was by myself

 

[TheRobSJ]

If it has a hard miss while it’s idling, then that makes it super easy to find.

While it’s running, unplug a coil (don’t worry you won’t get shocked) and see if it makes a change. If it does, reconnect it and move on to then next one. Once you get to one that makes zero difference in how shitty it isles, there’s your problem coil/plug. Swap it to another cylinder, and see if still doesn’t affect the idle on the other cylinder. If the problem moved with the coil, then replace it with an OEM part. If the problem didn’t move, maybe try swapping the spark plugs. If it still doesn’t move, well...you better hope it moved at this point.