Engine Knocking

70+K miles now. I've run premium probably 99% of the time from Day1. I sometimes get the pinging/rattling/whatever if I really "listen" for it, but usually the radio is on or my daughter is talking and the windows are usually closed or whatever so it's not that noticeable. My '04 Sienna's engine has always been a lot noisier than my old '85 Honda Prelude (270+K miles) or '96 Nissan Maxima (270+K miles)....probably more than my seldomly driven hand-me-down '91 Acura Legend (150+K miles) too. About the only car in my family that was MORE "noisy" than our Sienna was [spymom]'s old '87 Cadi Eldorado (110+K miles).....but that was more "belt whine" than the valves/pistons/whatever. I just chalk it up to "less than perfect" design/engineering/parts/etc.... :'( And [spymom]'s '04 Lexus ES-330 (30+K miles) shares the same engine as our Sienna, but it seems to be a lot less noisy than our Sienna..... ??? ??? :

YMMV.
Good Luck!! 8)

I have an open complaint with Toyota concerning the "ticking". My local dealer states the noise is normal. The tech states its lifter noise. The dealer does not want to hear about it unless they can fault Toyota and warranty it.(They state at this time they cannot fault Toyota.) They state the ticking is unrelated to the VVT service bulletin. I have noticed the ticking is greatly reduced when outside temps are 45 and above.

I must say you have to be very persistent and expect several canned responses prior to getting your concern forwarded to a review team. I have not heard anything from Toyota for about a month now. Don't forget to use the term "diminished value" when writing Toyota. There are several law suits out there were Toyota owners are alleging safety and quality have hurt their vehicles resale value. In fact one of the price guides(can't remember which one) recently reduced some Toyota vehicle values by a couple percentage points. I emailed Toyota a friendly reminder to see that my concern was still in the que. Below is the correspondence I received last month.

"Thank you for your recent correspondence.

Please be advised that we have sent your file, case number XXXXXX to our Review Team. Someone from our Review Team will be in contact with you shortly. We appreciate your patience in this matter.

We thank you for taking the time to write. "

I ask them to stand behind the vehicle with an extended service contract to show me they have confidence in there own product. This should be zero cost to them if they are confident that the noise is an intrinsic part of the design and will never poise a problem or reduce engine longevity.

Blah Blah Blah.

Results would be nice but I expect Toyota has their hands full "making it better" as posted on there most recent TV commercial.
I'll update the post if I get any further info.

Update:

Toyota basically told me to go fly a kite. All this after 2 months of trying to get an answer or a commitment from them.

Short story: The dealer could not find a problem and we(Toyota) trust our dealers to diagnose problems. If the dealer says you don't have a problem then you don't. If you are not satisfied with the dealers answer then you can take it to another dealer for a second opinion at your cost. If dealer #2 say you have a problem then will deal with it. If dealer #2 says you don't have a problem then sorry. By the way Canada does not have lemon lawsuit recourse(according to Toyota). The rep. was unable to disclose to me how many complaints they have concerning engine knock. "I'm unable to discuss that with you", was his response. When asked about the various complaints on websites, and owner reviews he stated something to the effect of, we don't look at blogs or spend our time looking at those things on the internet.

Solution: I called up Doug and got a quote for a Platinum warranty. I highly recommend Doug and Tara(Tara took my order since Doug was out). Very, Very competitive pricing. Just fire off my email to finalize the transaction.

If it truly is piston slap, then shouldn't it be worse under very cold conditions???

In my case.....
After a very cold startup (below 25 F) its actually quiet for a while. Then once it warms a little, the knock/ping starts and continues till the engine is completely warmed up to normal operating temperature. The knock/ping persists long after the heater is blowing hot air, at a time when I assume those pistons have warmed up nicely.

However, after initial startups on milder days (above 45 F) the knock/ping starts almost immediately and continues till the engine completely warms up. Of course, on milder days the knock/ping disappears sooner, since the engine reaches normal operating temp sooner.

If its truly piston slap, or some other cold tolerance condition, why isn't louder and immediately evident at the coldest startup?? And why does the noise persist long after the heater is blowing hot air??

Maybe I'm over-thinking this, but..... at very cold temps the parameters like air/fuel mixture, ignition timing, valve timing, etc are essentially fixed. Then as it warms up even slightly, these parameters start varying based on sensor inputs. Maybe the milder temps (ambient and/or mid very cold warmup) signal a different set of parameters, and cause this knock/ping to start? I'm suspicious of a bad sensor or actuator during warmup.

Any thoughts?