2006 Sienna Engine spark knock

My 2006 Sienna is having what sounds like a bit of a spark knock. This only seems to occur at slight acceleration loads. Under heavy acceleration, it runs great.

I can make it happen with a small amount of acceleration, and then holding the brake to keep from actually gaining too much speed. This seems to hold the engine in this condition allowing me to listen more closely.

I am quite sure it is spark knock and the computer should be compensating for this condition.

Any ideas on what could be causing this? I wonder if the knock sensor is bad, but seems a simple sensor like that would last longer than 5 years and 55,000 miles.

Thanks for any help you can give

I have a 2003 Sienna that does this.
I have the 1MZFE motor, and TOYOTA TSB# SB0125-08R1 is for this exact problem....pinging with slight accelleration up a slight grade.
In my case, the solution is to replace the ECM...."covered under the 96 month / 80K mile emission warranty"
Take note that I have a DIFFERENT MOTOR than your 2006.

My alldatadiy subscription only lets me see the information for the 2003 Sienna.
HOWEVER, you can look up TSB names for free......but need a subscription to read them.

TSB# EG055R-06 AUG 07 "Engine Controls - Pinging/Knocking On Light Accelleration"
applies to your 2006 Sienna.
Your dealership should be able to help you, or you may be able to look it up.
You can see the full TSB with a subsription to alldatadiy.
NOTE, a TSB is NOT a recall, although the "fix" might be covered under a warranty that might still be in effect for your vehicle.


I made my pinging less noticable with premium gasoline.....but some brands make no difference at all, and some are better.
So far Shell in my area seems to help.
However, in my case.....it is only under certain accelleration conditions on regular unleaded fuel.
Also....fuel can very from area to area,....here in the Milwaukee area, we have a "special" formulation of the 10% ethanol oxygenated fuel, required in all gasoline sold.
So 1 brand can be "the bees knees" in one area, but not so good in another.
The 1MZFE motor is supposed to be able to eek a bit more out of premium gasoline......it depends upon the ability of the engine controls to be able to adjust to the higher octane.
I have not experimented enough do know if that is the case for me or not.
I do NOT know if this is the case with the 3MZFE motor.

It would be very nice if the problem could be solved with a reprogram of your computer in your 2006......instead of a whole new ECM unit.
The ECM for my 2003 lists for over $1500, I see it on toyotaparts123 for just over $1069
The ECM for your 2006 lists for just over $1150, is on toyotaparts123 for $816
Oooch.....a bit expensive....but just a heads up as a comparison in case you are quoted a price for work to resolve the pinging issue.

Thanks for the info. I was was hoping for as much, but didn't know how to find out if a TSB existed for my problem.

Have a great day!

I took my van in to the dealer today. They installed the TSB and things seem better so far. I haven't driven it much yet really, but it didn't ping at all, so that seems good.

Thanks again for the help,
Ed