NEW!!! Service Bulletin for Engine Knocking at Startup T-SB 0012-10

I do not know what is causing the problem I can only mention the fuel method I described works for me. Since 87 octane is the recommended fuel I don't mind using 93 in the winter months.

NOTE: If you use lower octane then 87 the manual does say you can cause harm to the engine.

It would help if someone tried it, so we can confirm or reject the idea as a band-aid fix for winter time. Remember top tier gas stations do dispense fuel with certain additive levels.

I also don't believe they will ever fix it since it's still happening on 2013 cars.
my2cents

 

Your welcome prominence

Foot on Brake. press start, then immediately fully press accelerator to floor and release "one time only". If you a search you may find the reference. The post was shortly after the Gen III came out in 2010.
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"Pumping the gas pedal without the ICE running will do nothing to the throttle from what I was told. It may start the ICE, but it wont "prime" the ICE or move the throttle or other controls unless the ICE is starting up. Or something like that...."

gliderman...I can neither confirm or deny this, however when using this method I have not had even a small shudder event. I am not going to reason the engineering or learn anymore about it than needed at this point. This just worked and I moved on.

 

I found the post explaining the accelerator pressing method.
Here's a copy of what was discovered by PC member tumbleweed.

"The other thing I have discovered, when it is cold, starting the engine as soon as the Ready light comes on by pushing the throttle down and not waiting for the 15 second delay seems to eliminate the problem completely. This, of course, has nothing to do with the 15 second delay but, I think, the extra air that goes in due the the open or partly open throttle plate prevents the vibration from starting".

 

Thanks. There was an older post about this though.

 

What about incidents where the engine starts up at the exact same time, immediately when I press Start button, and there's not that 15 sec delay? That's what happens to me every time it's super cold, and that's when I usually get the WORST knocking incidents.

 

I have never used the petal down method but if you turn everything off in the car when you shut it down, things like the radio, auto lights option and other things it will help not start instantly.

The one critical item to turn off is the fan for the heater/AC setting when you shut off the car. The car remembers the last setting of the fan.

If the car senses a demand for heat or cold for the circulating fan and everything related to the system, it turns on the ICE almost every time.

Try this after driving for a while, at a stop light with the fan on with the ICE running.
Turn off the fan at the light, the ICE shuts off.
Hope that helps.

 

Maybe I have been working aircraft to long but it is standard operating practice (SOP) to turn everything off before shut down. I do this with all my vehicles and taught my Son the same while teaching him how to drive and operate a car.

I am sure there is a Tech or some Armchair Prius Guru on this site that can explain, confirm or deny the validity of this method to avoid "start up shudder". All I know is that I experimented with it and it works for me. The only events I have now are when I forget to cycle the pedal as previously described.

This is my work around and I will continue until/if Toyota (or anyone else) provides a permanent solution. YMMV.

 

How many times have you experience rough engine starts in your Prius and what is your mileage?

Thanks!

 

5 major events prior to engine mount T-SB (before 60K) and once shortly after. I began regularly using the accelerator trick after that. Car has just over 71,000 miles now.

 

Six events in 71k miles. You do the tango before you start your car.

I have had three events in 76k miles. I do nothing.

With all the electronics in the vehicle, I am surprised that it runs at all given the totality of possibilities on any given day at any given time.

Too bad they cant program the car to take snapshots of all the metrics in the minute leading up to and during the engine shudder event. Or any abnormal event.

 

I hardly think a single press on the pedal would be considered the tango. Remember the days of carburetors and manual chokes?

Actually I'm sure they do have what we call flight recorders that can be plugged in when needed. I know first hand Chrysler has them. That was the only way they could work out the software issues on our then brand new 2005 Durango, which is still going strong. Something in me says they know what the issue is, but I already commented on that.

 

It happened to my 2013 this past week for the first time (6900 miles) after the dreaded pulling the car into the driveway the night before. I will try these preventive suggestions if it happens again and see how they work. Thanks to everyone on Prius Chat for helpful info!

 

The conversation above reminds me of a great movie line from 1983 called "War Games".

General Beringer: "Goddammit, I'd piss on a spark plug if I thought it'd do any good!"

That's the great attitude I see here when it comes to problem solving.
People can try many things and everyone learns from their experiences.

So it's important to keep collecting experiences and details from everyone to see what sticks.

I started playing with the pedal start method, just to see if I can learn anything from it.
thx.

 

Bad luck streak. Went to drive the prius to the dealership for service appointment and of course check engine light is off this morning. Dealer says they can do nothing. Also brought up the updated manifold part # ending in 54. They weren't interested. Claimed they'd have to replicate my exact issue again to replace with -54 manifold and that -54 manifold is probably same part but simply updated parts inventory #. Total BS. so game plan is to never move the car a short distance in winter unless I let the ICE do a full warming cycle - seems to be the best preventative measure in my experience.

 

total bs is right. the code should be stored. is there another stealership near by?

 

wait, so the code should actually be stored even with the check engine light off?

i'm just so exhausted from this whole issue that I'm just going to avoid moving the car short distances unless I let the ICE do a full warm up cycle first.

I've contemplated other vehicles, but prius is my baby and not interested in other cars. Sucks, haha.

 

Yes. The control unit will store a history of the codes until it is cleared. Some CELs will cause the light to stay on until they are cleared (depending on severity I guess).

So far we have not heard any confirmed cases that this issue caused engine/component failure. Try not to worry about it.

 

2013 Prius V Wagon cold start engine knock! Car has 7543 miles. Washed car on Wed. with temps in lower 50's. Moved the car into the garage where it sat Wed night and all day Thurs (Thanksgiving). Temp in garage about 40. Started Fri morning, knocking, clanging, thought it was going to shake to pieces. I immediately shut it down checked oil, looked over with a flashlight found nothing. Called dealer in Ft. Worth. My first call he basically said, nothing we can do without engine light on, just keep an eye on. Called back 2nd time for his name, told him I'm documenting issue. He suggested bringing in for a check out, should take 1.5 hours. Taking in tomorrow, no engine codes showing. I printed out TSB-0010-12. We'll see...

 

I hope your not taking it to Toyota of Fort Worth. If you are, turn your recording device on when you talk to the service writer. Then ask to talk to a service tech that has done the TSB and ask him what codes are stored that would prove this event and suggest the TSB service to be performed. The check engine light doesnt have to be on.

 

Thanks, Maybe I should take to Durant Toyota in Granbury where I bought it?