Hey, what happened? (Honda)

I just did some work on my '97 Odyssey, which included removing the upper intake plenum.

When I went to restart, it wouldn't fire.

After a bit of head scratching, I found the spark plug wells flooded with oil. Really flooded. Like, fully submerged. All 4 of them.

So, I would normally just get started on replacing the valve cover gaskets and the well seals under the cam shaft assembly.

But I'm trying to figure out what happened. I drove the car into place yesterday. There is no way it would have run with the spark plugs completely submerged in oil, and an oil leak of this scale didn't happen overnight while it was sitting not running. I spent a lot of time with my chest resting on the valve cover, reaching over it for the intake.

So, gurus... Did I screw something up? Is it possible to have reversed some wiring or vacuum lines on the intake plenum that could have pressurized the crankcase (while cranking, not running)? What else could have caused this? A clogged crankcase breather? Leaning on the spark plug boots with dried out seals? Other?

One note- it was driven into place with the TPS disconnected. Pumping the gas to keep it alive.

It has not been fired since the plenum was re-installed. Just submerged in oil.

Thoughts? (Yes, I am asking for your opinion).

I think it must have been like that.

If im picturing this right, what i think may have happened is that the plug boots, maybe having been undisturbed for a long time, had formed a good hermetic seal to their respective plugs, and while the plug tubes may have been full of oil, it wasn't presenting a path of lesser resistance because it was being kept outside the boot/plug interface area.

BUT since you were leaning across the valve cover, you probably put body parts on top of the plug wires and jostled them somewhat, thus disturbing their hermetic seal to the plug body and allowing oil to wick up into those areas until it DID become a path of lesser resistance.

I know... not the most likely story ive ever come up with. But im still posting it.

I had my Accord run just fine with the spark plug wells filled up with oil.

Are you sure that removing the oil will make the van run? It's possible there's a different problem and fixing the oil bathed plugs won't make the van run.

SVreX wrote: Thoughts? (Yes, I am asking for your opinion).

I am of the opinion that vanilla ice cream is better than chocolate.

Sorry I know nothing of Hondas.

Actually, a spark plug will fire in oil provided there isn't very much inside the boot. My guess is the valve cover spark plug seals were toast and you removed the wires from the plugs for access or disturbed them in some way.

I've worked on many Hondas with the plug wells filled almost to the brim. I would check the secondary wiring to the coil(s) or you possibly disturbed part of the wiring harness.

There was lots of oil in the boot. Right up to the top.

But I will double check the secondary wiring.

The valve cover was loose when I tried to remove it, and the lower seals (under the rocker cage) where hard as crap. They came out in little pieces.

I'm thinking a little like Vigo, that these hard seals had kind of formed there own hermetic seals. They were happy, and undisturbed, until I leaned on the valve cover for a couple of hours (pushing down on those hard seals).

So I replaced all the seals and gaskets.

I'll get it back together tomorrow, and get back to you.

Thanks, guys.

SVreX wrote: There is no way it would have run with the spark plugs completely submerged in oil,

Sure it would. Happens all the time. Usually the car runs great and we notice the problem when swapping spark plugs.

In reply to Knurled:

OK. So what's your theory why it won't start?

You broke it...

yeah, ignore the oil, you missed something COMPLETELY unrelated.

I changed a starter on a 96 and then it cranked and would not start. Turned out to be the injectors leaking and flooding the spark plugs. Serviced the injectors and all was good.

You guys were right on the oil. I now have no oil leaks, new plugs and wires, a valve adjustment, but still no fire.

Going through the wiring this afternoon.

Its weird it happened after you worked on it. I would try to retrace my steps and make sure nothing was left unplugged.

I doubt this is your problem, but maybe worth a check?:

http://www.fixya.com/cars/t8847148-honda_oddessey_1995

I would guess that the oil has accumulated in the plug wells over time due to a leaking cam cover gasket. As you worked over the engine, the plug boot sealing was broken resulting in oil on the plugs. In my experience, water and oil on the china of the plugs causes misfires.

That may be why it won't start. Otherwise , a sensor may have been left unplugged. Revise your work and something will pop up

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Slippery wrote: Its weird it happened after you worked on it. I would try to retrace my steps and make sure nothing was left unplugged.

I agree.

I am not aware of anything related to the intake (vacuum, related sensors, IAC, high idle sensor, TPS, air charge sensor, etc) that would completely prevent it from starting. Sure, it would run rough, but it still should start.

Didn't know if any Honda gurus might know something I don't know.

I have been over this 100 times. Not finding anything.

Vigo wrote: I think it must have been like that. If im picturing this right, what i think may have happened is that the plug boots, maybe having been undisturbed for a long time, had formed a good hermetic seal to their respective plugs, and while the plug tubes may have been full of oil, it wasn't presenting a path of lesser resistance because it was being kept outside the boot/plug interface area. BUT since you were leaning across the valve cover, you probably put body parts on top of the plug wires and jostled them somewhat, thus disturbing their hermetic seal to the plug body and allowing oil to wick up into those areas until it DID become a path of lesser resistance. I know... not the most likely story ive ever come up with. But im still posting it.

I had this problem with a corolla a while back. It also masked the real no-start problem, which made it very fun.
But I think that is exactly what caused the oil bath

How old is the ignition switch. There was a recall.

stan_d wrote: How old is the ignition switch. There was a recall.

It cranks, but won't fire.

Are you saying the ignition switch could be the culpret?

don't hondas of that vintage have a main relay that chronically fails?

It cranks, but won't fire. Are you saying the ignition switch could be the culpret?

Well, the power to the starter circuit and the power to the engine computer are on different circuits so it's possible a failing ignition switch could affect one without affecting the other. However, i'm not saying that's what it is.

Do you have spark when cranking the engine? Can you ever hear the fuel pump?

Fixed it.

It was the main wiring harness ground. It had slipped down behind the engine where I couldn't see it.

Plus, the attachment point to the intake plenum is in a really obscure spot, so I never noticed.

But I gotta admit... I thought you guys would catch me at something THAT basic!

Thanks for your help!

I'm guessing it wasn't the MAIN ground, otherwise you got really lucky. I've left the main ground off and cranked the motor and smoked significant sections of the wire harness as the starter grounded 300 amps through a bunch of tiny wires.

Congrats on the fix!

Main harness ground. There are not a lot of repetitive grounds on this car like more modern ones. Injectors, ECU, etc. ground to a single point coming off the main harness.

The MAIN ground (battery to chassis to starter) was intact.

I did. I said check the secondary wiring which includes the ground.