I have had a 2001 Sienna that has served me well for 120,000 miles until someone totaled it for me a few weeks ago. I replaced it with an 01 Sienna that currently has 70,000 miles; but, I have run into a problem. It pings.

I came up in the old school when timing was set with the twist of a distributor and spark plugs were an easy, twenty-minute job so I have no idea how to fix this pinging problem or what might be causing it.

Any more info? Is the pinging coming from inside or out? Does it only happen at certain times, or always? Any other info might help.

I'm familiar enough with valve clatter that I can say with certainty that is what it is.

It happens on acceleration and when on slight ot steep grades and at all speeds above about 20 MPH.

you may want to check some of the Toyota TSB's. I know that the Sienna's in that model year range suffered from oil sludge problems and Toyota had to settle a class action lawsuit cause of it. ...

Try running 2 tanks of premium (High Octane) fuel, use at least Octane rating of 92, and see if there's any difference.

I had an '01 Sienna before this one that never had a pinging problem and I never ran any higher octane gasoline in it. Even if the higher octane gasoline made a difference, I would not consider it a satisfactory solution as the difference in the price of the two gasolines is unacceptable.

I want this Sienna (which is identical to the last Sienna except for the color) to run as well on the same gasoline as the last one.

That may not be reality my friend.

Engine knock is not necessarily a death-knell for an engine. Tons of vehicles ping. My 4Runner pings too.

You may be able to take it in and get it adjusted (not sure about that because it would need a PCM adjustment).

What my suggestion was, about the higher octane, was try to see if that eliminates it because if it does the pinging is not that big of a deal. If it still pings it may point you to a more major problem. Try it for a couple weeks.

I am trying your suggestion.

I ran the tank as empty as I dared risk of being stranded. I have been running 87 and upgraded on this tank to 93. I have only 20 miles on it so far; but, I haven't noticed any pinging yet. I'll let you know if any pinging shows up.

I usually get 250,000 miles and up out of a car as I run service twice as often as recommended by the manufacturer. I want the pinging fixed and if it takes service or replacement of parts, I'll do it. Continuous ping cannot be good for any engine and, still, using higher-priced 93 octane is a more expensive solution than I care to use. At current prices, that amounts to well over $3000 over the life of the car.

By the way, what's PCM?

I've been noticing that the higher gas prices get the more water I seem to be finding in my gas at 87. My mechanic said he and a few others have noticed it as well. I switched gas stations and PRESTO, no problemo!

PCM = Powertrain Control Module
aka...the vehicle's computer.

Jeez Accer...that's a very good point. I remember in one of my old vehicles when I got pinging i also switched to a different gas supplier and the pinging went away.

In fact, I got more pinging with Esso. I went to Shell and voila...no pinging. I know Esso gas uses different chemicals than Shell during refining...they have been subject more to the environmentalists wrath than the other refiners.

Alex, this is a good suggestion. Since you've already said your pinging is gone with 93 octane....try switching to another reputable supplier, and go back to 87 octane.

Well, I don't use a single brand. I use el Cheapo, Shell, Chevron, Exxon, whatever is closest. I did the same with the first Sienna and the same with this one. The Pinging is consistent whatever the brand.

By the way, I've put about a hundred miles on that 93 octane ans still no ping.

I now have about 300 miles on that 93 octane tank. The ping is reduced significantly; but, it is still noticable.