Misfire when warm under load

DN12O-ody · Apr 7, 2022

With my 2012 EXL, it misfires pretty consistently once the car is fully warmed up and the engine is revved above 2500 rpm or so. Won’t rev above 3000. Multiple P030X codes. 125k miles. Runs great when cold.

The valves have been adjusted, as well as all coils and plugs replaced. This was by a local indy honda specialist. Took it to the dealer, they said compression was low and that it needed a new engine, but I had difficulty getting any more info from them beyond that.

Its Probably not worth an engine swap or ring job, but is there anything else I might check before giving up the car to the scrap heap? 🙁

thank you.

2011.2017.odyssey · Apr 7, 2022

code specifics would be helpful.

also with 6 posts in you must of read about VCM issues and how to disable it.
read the vcm megathread by WiiMaster

DN12O-ody · Apr 7, 2022

Codes were 0305, 0306, and 0300. Yes, I’ve read up on the VCM disable but was wondering if it was too little too late at this point.

WiiMaster · Apr 7, 2022

DN12O-ody said:
Codes were 0305, 0306, and 0300. Yes, I’ve read up on the VCM disable but was wondering if it was too little too late at this point.

Then read the megathread fully. There is no such thing as too late, and it is addressed in the megathread. Though 5 and 6 are non-VCM cylinders.

2011.2017.odyssey · Apr 7, 2022

DN12O-ody said:
Codes were 0305, 0306, and 0300. Yes, I’ve read up on the VCM disable but was wondering if it was too little too late at this point.

those misfires are not vcm related, although the bad compression on certain cylinders may be.
Did they give a compression test report for all cylinders?

MrRangerZr1 · Apr 7, 2022

Did it jump timing? Check timing

phattyduck · Apr 7, 2022

DN12O-ody said:
all coils and plugs replaced

What brand and what was the source for each of those? (since it is a Honda specialist, hopefully they used the right parts - but worth checking)

-Charlie

2011.2017.odyssey · Apr 7, 2022

MrRangerZr1 said:
Did it jump timing? Check timing

good point...would the valves survive a tooth jump on the belt?
because those symptoms do seem like timing.
a malfunctioning ckp could also cause this, along with a bum pcm.

DN12O-ody · Apr 7, 2022

Thank you all for the ideas.

Timing Belt was replaced 25k/2 yrs ago. Coils were Honda, not sure about plugs, I will check.

Dealer wasn’t forthcoming on compression numbers, I got the sense they were just trying to get me out of the shop as quickly as possible. ;-)

DN12O-ody · Apr 7, 2022

It’s a long shot, but what about a borderline fuel pump or semi clogged filter? (Knowing that they are the same unit).

WiiMaster · Apr 7, 2022

Just because the timing belt was replaced doesn't mean the timing can't be off.

Fuel pump issues are almost unheard of on Hondas.

DN12O-ody · Apr 7, 2022

Understood. Can a garage check the timing without physically accessing the timing belt (just from diagnostics), or do you have to get in there. To check it?
thanks again.

edit: interesting too that when cold, you can rev it to redline and it’s perfectly smooth. If the timing was off, would it misbehave all the time?

WiiMaster · Apr 7, 2022

DN12O-ody said:
Understood. Can a garage check the timing without physically accessing the timing belt (just from diagnostics), or do you have to get in there. To check it?
thanks again.

edit: interesting too that when cold, you can rev it to redline and it’s perfectly smooth. If the timing was off, would it misbehave all the time?

You can remove the upper timing covers and rotate the engine to see if the timing marks line up.

MrRangerZr1 · Apr 8, 2022

2011.2017.odyssey said:
good point...would the valves survive a tooth jump on the belt?
because those symptoms do seem like timing.
a malfunctioning ckp could also cause this, along with a bum pcm.

One tooth off it may not bent valves

MrRangerZr1 · Apr 8, 2022

DN12O-ody said:
Understood. Can a garage check the timing without physically accessing the timing belt (just from diagnostics), or do you have to get in there. To check it?
thanks again.

edit: interesting too that when cold, you can rev it to redline and it’s perfectly smooth. If the timing was off, would it misbehave all the time?

Can check with the inspect holes on the covers.

With the timing off by say a tooth, at first It will seem like it runs like a charm, will even go to redline. But it will start misfiring very soon after. I dealt with a van like this before. Hopefully you don't have any internal damage.

DN12O-ody · Apr 11, 2022

Timing looked fine. So I decided to roll the dice and installed a new fuel pump. Ranger’s YouTube video on that process was very helpful. And surprise surprise… it seems to have fixed the problem. Driven it for a couple of hours since in many conditions, and no more misfire.

Misfire when warm under load

DN12O-ody

2011.2017.odyssey

DN12O-ody

WiiMaster

2011.2017.odyssey

MrRangerZr1

phattyduck

2011.2017.odyssey

DN12O-ody

DN12O-ody

WiiMaster

DN12O-ody

WiiMaster

MrRangerZr1

MrRangerZr1

DN12O-ody

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