T-SB-0010-12 Loud engine knock or rattle noise.

I have the knock when starting but haven't been in for service yet.

 

every time? best thing is to let it finish the warm up cycle. hopefully the tsb will fix it, but it hasn't completely in the liftback, iirc. good thing about the pip is, you don't have to start it for short trips.

 

I've had it just one time too- and I predicted it would happen on my next start-up... which it did.
It's very easy to "make" the gen III Prius cold start knock once you know the conditions that cause it.

 

I have not experienced it so far.

 

Here's the "how to" produce cold start knock on the PIP...
Keep your PIP outside in the cold (below freezing)- run the EV batt down to where there's only HV driving left- let the PIP cool down over night, move the car down the street so the ICE starts up, run the ICE for maybe 60 seconds- park the car and immediately turn off the ICE. Don't plug in and charge the EV bat. The Next day when you try to move the car- the ICE will be a shaking!

The above seems like a far fetched scenario- but it happened to me after a big snowstorm in Feb.
I came home Wed with the EV bat depleted from my drive from work- forgot to plug-in and recharge because there was storm prep to be done before it got dark. The next day (Thurs) I backed out of the driveway to move the car to the now snow cleared part of the driveway. Having no EV range left- the ICE started as soon as I moved out on the the street. I then proceeded to the other side of the driveway under ICE power and once in the correct parking spot- turned off the ICE- a short 50 foot trip with total ICE running time of maybe 60 seconds. Being a snow day with no work- the car sat in that spot all the rest of Thurs till the next morning. Fri morning when I pressed the ign button the ICE immediately fired up because it was down in the single digit temps the night before... and that's when all the rattling and shaking started.

 

Once when I started and stopped and started the Ice when it was cold. Didn't take it to dealer, if it happens more that 2 more times I would, but it hasn't.

 

So it sounds like it isn't an issue if you let it complete its warmup cycle.

 

Yes, correct- that will 100% prevent it.
But it seems sooo wasteful to let your Prius run in Park for 5-10 min in your driveway just because you moved it 50 ft.

 

in almost 2 years, i have had to let my ice warm up a handfull of times. usually because it fired up just before i got home. as far as moving it in or out of the garage, around the corner and etc., this is easily accomplished in ev.

 

I have shutdown before warm up completed but not under freezing temp.

 

It's only happened one time? And what's the mileage on the odometer?

 

I'm just under 21,000 miles on the PiP and it hasn't happened yet.

 

You just haven't satisfied all the conditions to reproduce it..... yet

 

Mine does it everytime the ICE starts when cold. Ambient temps don't seem to change this behavior. I can count the times I've moved the car without going through a full warm-up on 1 hand. 3300 miles on the car.

 

You left out what actually causes it. It is the flash freezing of water vapor, a product of combustion, onto the metal surfaces of the combustion chamber. Surfaces like the cylinder, piston, valves, spark electrode, and fuel injector nozzle. Running the ICE for such a brief period doesn't produce much heat relative to the mass of these metal parts whose temperature is near or below freezing hence the formation of ice or frost on these surfaces. Evaporating fuel also adds a significant cooling factor. All ICE have this rumble start under these same conditions it's just that the high torque of the starter and open throttle fuel dump into ICE during startup rapidly over comes this ice/frost stickiness. One of those things that has always been around but to rare and brief in occurrence to be memorable.

Shutdown and restart and or just let combustion heat and the knock sensor take care it for you.

 

and what is the tsb solution?