2007 Honda Pilot 3.5 multiple misfires
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Foot to the floor on this model while cranking should put it in clear flood mode by shutting down the injectors.
I assume the harmonic balancer bolt will be an issue. (Presuming the HB will have to be removed to check the crank alignment marks.). Apparently there's a weighted socket that helps.
More background:
The CEL was on before yesterday (diagnosed by a shop as an O2 sensor problem, presumably based on the cat codes P0420 and 430), so the misfires don't seem to caused other problems yet.
I'm hoping that if the TB has jumped one tooth, the valves are not out of time enough to have contacted the pistons.
Lots of other troubleshooting to do first.
The CEL was on before yesterday (diagnosed by a shop as an O2 sensor problem, presumably based on the cat codes P0420 and 430), so the misfires don't seem to caused other problems yet.
I'm hoping that if the TB has jumped one tooth, the valves are not out of time enough to have contacted the pistons.
Lots of other troubleshooting to do first.
BrendanC
$100 site donor 2024
not on honda’s/nissians. they will rev to the moon
found that out when i did a parking lot oil change on my now Wife’s car when we first met.
The Honda J35 is also a great candidate (other than the pain of reaching the rear plug holes) for B12 soak considering its issues. First order of business would be to install a VCMuzzler or similar device to stop the cylinder deactivation.
Was this on an 07 3.5 Pilot?not on honda’s/nissians. they will rev to the moon
Check engine vacuum. If poor, needs valve adjustment.
As others have said, make sure it is in-time. Don't remember if that era had the rubber plugs in the timing belt covers, I think they did. Time it to TDC and make sure the marks line-up.
As others have said, make sure it is in-time. Don't remember if that era had the rubber plugs in the timing belt covers, I think they did. Time it to TDC and make sure the marks line-up.
I assume you checked the plugs and coils? For misfires that should be the first thing checked before digging into timing belts, sensors, pressure checks, or whatever else.
My sister has an '07 Pilot, 3.5 AWD. Out of nowhere, we got misfires on five of the six cylinders. I pulled the coils.... three of them melted, one burnt but not yet melted, one charred but still useable and one perfectly good one (Surprise! On the not-misfiring cylinder).
I started to remove the plugs and on the first one I thought the socket wasnt sitting right because there was no resistance at all to the ratchet. Nope, it was simply that loose. Five of the six plugs could be removed simply by hand, not using the ratchet, just me turning the extension with my fingers. The plugs and threads were coated with carbon all the way up to the top. The last one was still tight, and looked fine.
Six new plugs, four new coils and a lot of expletives and three months later it still runs like new. Oh, and of course the intake tube was cracked right in front of the throttle body, like they all are.
If you're cheap like I am, hit the local junkyard. There will be dozens of 3.5 V6's and you'll be surprised, or maybe not surprised, by how many fairly new coils you can grab, and how many brand new intake tubes you can find, saving you hundreds. Also note there are different intake tubes on Pilots, depending on the model year and whether or not its AWD.
My sister has an '07 Pilot, 3.5 AWD. Out of nowhere, we got misfires on five of the six cylinders. I pulled the coils.... three of them melted, one burnt but not yet melted, one charred but still useable and one perfectly good one (Surprise! On the not-misfiring cylinder).
I started to remove the plugs and on the first one I thought the socket wasnt sitting right because there was no resistance at all to the ratchet. Nope, it was simply that loose. Five of the six plugs could be removed simply by hand, not using the ratchet, just me turning the extension with my fingers. The plugs and threads were coated with carbon all the way up to the top. The last one was still tight, and looked fine.
Six new plugs, four new coils and a lot of expletives and three months later it still runs like new. Oh, and of course the intake tube was cracked right in front of the throttle body, like they all are.
If you're cheap like I am, hit the local junkyard. There will be dozens of 3.5 V6's and you'll be surprised, or maybe not surprised, by how many fairly new coils you can grab, and how many brand new intake tubes you can find, saving you hundreds. Also note there are different intake tubes on Pilots, depending on the model year and whether or not its AWD.
True, but he did say a misfire on all cylinders.
That was my first thought as I started reading @RedSpider's post, but then he mentioned that his misfires did all start at once, with the plugs and coils presenting as bad.
I'll start by pulling the front coils and plugs (once it warms up a bit). Still cold here.
If the TB has skipped a tooth, would that would also present as low vacuum?
Messed up valve timing can definitely affect engine vacuum.
Wednesday through Saturday are looking good - hopefully we can pull the plugs on the front bank.
Contradictory information on the 'net, as usual, but can I assume the front bank is #1, #2, and #3 (passenger side to driver's side)?
1, 2, and 3 are bank 1, closest to the firewall. 4, 5, and 6 are the bank closest to the radiator.
Checking the valve timing is relatively easy, the timing marks for the crank are on the pulley and on the timing cover, and there are inspection plugs in the cam covers.
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If it is a manual and you park it on a hill they are known to jump teeth on the timing belt. Funny my buddy sent me this pic just yesterday from his souped up 3.5 with a turbo that we ran last week. Turbo bearing failed and luckily we saw the first puff of smoke and shut it off to save the engine. Turbo bearing failure lets tubo oil into the intake. These are the chunks that fell out of the intercooler. As noted above, check your timing marks.
Thanks, we'll pull #4, #5, and #6. I think there were misfires on all of them, and two of the other three (#1, #2, and #3).
We may not have seen a misfire on #1, which is actually encouraging in that it points toward plugs and coils rather than timing (which would be common to all six).
Yesterday was fairly mild (not much below freezing) and we had a window of time to work on the Pilot. The spark plug in #4 was pretty tight, so we moved on to #5 and #6.
No smoking gun - none of the three coils showed any external sign of damage. (Is there a resistance check I can do on the three pins on each coil?)
Plugs #4 and 5 looked like they had some miles on them, and had a light coating of black soot (I assume from the recent misfires) but gap was not excessive (around 0.045", spec is 0.039 - 0.042") and the centre electrode on each plug was slightly rounded but not too badly.
We tried to check that the cams were in time, but were unsuccessful - the little inspection windows on the upper timing covers are frustrating. It's very hard to see anything relevant through the one on the rear bank.
We also had trouble finding the timing marks on the harmonic balancer.
The plan now is to pull the upper timing covers.
No smoking gun - none of the three coils showed any external sign of damage. (Is there a resistance check I can do on the three pins on each coil?)
Plugs #4 and 5 looked like they had some miles on them, and had a light coating of black soot (I assume from the recent misfires) but gap was not excessive (around 0.045", spec is 0.039 - 0.042") and the centre electrode on each plug was slightly rounded but not too badly.
We tried to check that the cams were in time, but were unsuccessful - the little inspection windows on the upper timing covers are frustrating. It's very hard to see anything relevant through the one on the rear bank.
We also had trouble finding the timing marks on the harmonic balancer.
The plan now is to pull the upper timing covers.
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