Honda Odyssey 2009 engine ping problem

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Purchased a 2009 Honda Odyssey about six weeks ago.

I noticed some (slight) engine knock on the 2nd tank of gas (the first tank was supplied by the dealer). It may have been there on the first tank, but certainly not to the degree it was present on the 2nd tank.

Heard it primarily in 1st gear acceleration, and also when I've been coasting and then I press on the gas slightly. Kinda sounds like a diesel engine for a few seconds.

I only hear it if I have the windows open. It helps if I'm driving in a quiet area and I can hear the noise reflect from nearby cars that are parked on the road.

This 2nd tank of gas from my local Shell station. After it was gone, I bought a tank at the Mobil station. Engine ping substantially reduced. Have to really listen and work at it to get the noise again.

When that tank was gone, I thought it was all my imagination and bought another tank of Shell. The diesel noise was back in all its glory.

Just finished that tank, and I'm back to Mobil, ping very hard to identify again.

I'm using regular unleaded (87 octane).

Found this thread at Edmunds:
http://townhall-talk.edmunds.com/Web...?displayRecent

Everyone is talking about older models ('08 and previous). The problem seems to be primarily related to the knock sensors for those years (being improperly installed). And I'm not sure I'm hearing knock, and if that is the same as ping. I know the best way to describe the noise is diesel-like.

I'm kinda surprised that switching from Shell gas to Mobil would largely clear-up the noise. I'd like it to be completely gone, but I note that the tank holds 21 gallons and I think I put in approx. 18.5 gallons of Mobil this morning. So there is still some Shell gas in there.

I went to the Honda dealer and took the service guy for a ride. He heard the noise, told me it was nominal enough to run through the rest of this tank, and then asked me to fill up at the SpeedWay next door to them (where they buy gas), and then report back.

Any comments from anyone?

I've been using that Shell gas for quite a while. Perhaps they just have crappy gas but my other cars were more tolerant. What, besides octane rating, could contribute to the type of problem I'm having?

Any advice or comments about how to proceed would be welcome.

[eezlock]

engine ping problem

Try a higher octane gasoline.

[dbhost]

Take it to the service dept and get it fixed. Unless you are running regular unleaded in a car designed for higher octane fuel... Then pony up to a higher grade of fuel...

Octane rating is the measurement of the resistance to pre-detination of a certain fuel blend. So 87 octane should be 87 octane. But here's the catch...

Octane is rated on Gasoline, NOT M15 (15% Oxygenate 85% Gasoline) the typical oxygenate is Ethanol which will reduce your effective Octane rating...

So say for example Shell is selling M15 with a rating of 87 Octane, and Mobil is selling M10 (10% Ethanol) with a rating of 87 Octane. The effective octane rating of the Mobil would be more accurate than the Shell fuel. And in certain markets that border on areas that require Oxygenated fuels and those that do not, one brand of gas might have Ethanol where another might not.

I do believe MTBE is no longer in the auto fuel equation as there were leakage and contamination problems caused by MTBE when they first brought that garbage out...

I just wish that Gasoline was Gasoline still, not a gas / alcohol mix. I recall when oxygenated fuel was first introduced in Arizona, my gas mileage went down by 20% every winter when they brought that garbage in.

[LCHIEN]

ping is usually caused by improper spark advance and too low a octane fuel.
Virtually all cars now have electronic ignition control and ping sensors so the engine ignition timing is servo controlled and should compensate adequately even if the fuel octane is below what the car is recommended to use.

I have not heard a car ping in probably 20 years except when dieseling with the ignition shut off.

If its audibly pinging it seems to me that something is wrong with the vehicle.

[Kristofor]

Octane is rated on Gasoline, NOT M15 (15% Oxygenate 85% Gasoline) the typical oxygenate is Ethanol which will reduce your effective Octane rating...

Nope, Ethanol will raise the effective octane rating. E85 has an octane equivalent of ~105, and pure ethanol of ~116.

I'm kind of with you on the part about not liking the oxygenated fuels though... It does hurt milage, it's not that great for the broader environment (we pump TONS of groundwater to feed the ethanol plants), the process is not very efficient for energy in/out. That said, it really does help with air quality, so pick your poison I guess...

[jbrain]

http://www.odyclub.com/index.htm

Odyclub. I've been a member for years. Great info there for anything Honda Odyssey related.

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http://www.odyclub.com/index.htm

Odyclub. I've been a member for years. Great info there for anything Honda Odyssey related.

jbrain, that is great, thanks!

I signed up and searched for "ping." Lots of good information.

I had a chance to drive the car more this evening and on the way back from the softball game (a long drive allowing the engine to warm up quite a bit, where the symptom was its worst), I couldn't detect any pinging. I took it up a steep hill (at low speed) and nobody in the car (everyone having been able to detect it before) could hear it this time.

From my reading it would seem that the engine has 10:1 compression, and that 87 octane is a bare minimum. Would it be possible that the Shell pump says 87, and isn't? Would there be a way to find out that doesn't cost a fortune? I'm just curious.

[crokett]

We've had our '08 Odyssey since November and never any ping problems. It has only run 87 octane in it. I would say it is something in either that gas station or Shell gas. I've had cars not like gas from certain stations before. My Saturn would knock if I ran Mobil but not if I ran BP.

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Try a higher octane gasoline.

I have a feeling that is what I did by switching to Mobil.

I think next time I'm going to try the station the Honda dealer suggested, and go with the mid-grade and see what happens.

Interestingly enough, the Honda forum jbrain mentioned has comments that say for towing, you have to use a higher octane fuel. So I'm thinking they really do depend on a bare minimum of 87, no screwing around.

[crokett]

I guess it depends on what you want to tow. I tow my little 1000lb rated trailer about 2x a month on average and no problems with my van. Of course I never really load it out much. Heaviest load I've had on it is a stack of plywood that I think was the initial cause of the hub failing.

[LinuxRandal]

[QUOTE=cgallery;421691
From my reading it would seem that the engine has 10:1 compression, and that 87 octane is a bare minimum. Would it be possible that the Shell pump says 87, and isn't? Would there be a way to find out that doesn't cost a fortune? I'm just curious.[/QUOTE]

First, was the shell station used, the same one? If not then ignore this completely.

If it was, you might try calling the state people that come out and test the gas, as if it has too much water (say a leak around the tanks, or lids left ajar while trying to fill when raining), you could get enough in there, that it would drop the octane, but still burn. To much water, and it will kill a fuel pump and won't operate.

It could be as simple as the one station having an issue.

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First, was the shell station used, the same one? If not then ignore this completely.

Yep, same station.

[LinuxRandal]

Yep, same station.

Then their method of testing (the station near them, that even thought they don't own, they have a vested interest in) is valid, as long as they don't get the same gas truck as your station.

I've seen two things happen.
1. A truck with either a mismarked or bad load, goes and fills up multiple stations (even those that are supposed to be brand specific, may buy if they are low on gas).
2. Gas stations do develop leaks.

If it is just the station, then either their gas station or another shell, way off the route would tell that. If it was bad gas from a truck, then multiple stations will have issues (whatever the route is, can be harder to detect).

If it is water related, some Heat or Seafoam, would help.
I hope it is that simple (inexpensive), good luck.