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

RxGATOR,
Our 2012 Prius had its first "rough start" and have similar symptoms. I washed the car during the day and the car didn't get driven, it was parked right back to the garage. Over night low in OC, CA was about 43 degrees and at the time of me trying to start it up was probably around 50 degrees. Car has about 18,000 miles. Might have Toyota take a look at it during the next maintenance.

 

Hi everyone,

Just wanted to report back - it's gotten really cold and snowy in Ohio, and a month or so after my repair, guess what?-- KNOCK KNOCK this morning! I'm adding my voice to the rest of the posters here that are saying the repair DOESN'T fix the knocking issue!

 

Now that it's below freezing again, I'll see if the cold-start knocking comes back. I'm hoping it was just an inferior brand of gasoline (Conoco). I've since switched to a better brand, Shell. It's been starting smooth so far.

 

Bought my prius v back in August. I currently live in Edmonton, Alberta. My prius has seen -30 Celsius and has not had any knocking while starting in the extreme cold.
This past week I have been on vacation with my prius in vancouver and am currently on vancouver island visiting some friends. Last night it was 0 Celsius and when I started my v heard the engine make this terrible knocking sound for 5-10 seconds. I tried pressing on the gas pedal to make it stop but could not get the engine to rev. Put it in drive and pulled ahead a little but all I could do is wait for it to work itself out.
So from my experience I can only assume moisture is the cause of the knocking. The wet coast is very humid, Edmonton is extremely dry.
I'll be video recording my startups from now on and booking a checkup with Toyota when I get back to Edmonton.

2012 prius v 17000km on the odometer.

 

Yup, that is my experience and assessment as well. I think it has everything to do with the amount of humidity and the dew-point. Just so happens that is more common at lower temps. Some members help that along by washing the car.

 

I asked my service adviser about this yesterday. He said it happens rarely but he has seen it. He said he spoke to Toyota and this is what he was told. He sounded like Toyota knew exactly what it was and he was sure that what he told me was the official Toyota explanation. Now........I did not understand everything he said and I am not trying to say he is right..........I am just telling you what he told me.... for what its worth. He said that under some specific circumstances (and he gave several examples that have been mentioned by several of you here) the hybrid engine and the ICE start up at the exact same moment and that noise is somehow the two clashing when that happens. He said Toyota has duplicated it and is certain that it causes no harm to anything. So....there you go. That is that I was told yesterday.

DROID RAZR ? 2

 

Bought my wife a 2012 Prius V back in september. We just started getting really cold temps here in IL. Lows at night down in single digits and teens. We have started experiencing the violent engine starts and knocking. We are dropping the car off tuesday night, so it will sit overnight and the temps overnight are supposed to be single digit to below 0. So I am positive they will be able to see what is happening. If not, I have the tsb printed out. and will be taking my own video as well as showing them the ones on here.

 

On my youtube channel I have a video of my 2011 Prius knocking. A vistor who has a 2012 Prius left this comment:

"Quick update, i watched the tech remove the throttle body and low and behold guess what we saw, Oil in the bottom of the breather assembly. Hummmmm. The tech told me that toyota just redesigned the 2012 manifold. Should have the car back monday and i will keep updated"

Anyone else have this issue or heard of oil in the breather assembly? Might be two seperate issues but wanted to check.

 

In the Gen 2 I believe oil in the breather assy. was a sign of oil overfill?

 

Hey folks.... My 2010 had problem, I showed dealer the

my dealer replaced mine based on info I reported, video a PriusChat user provided and the TSB.

It didn't hurt that a salesman at the dealership who just bought a 2012 experienced the rough deisel sound the same week as mine.

The dealership changed out the intake manifold on both.(been though the 2012 wasn't in the service bulletin. I did not have any bill either.

My only current issue was being dead as door nails in a matter of minutes. Drove it in the a.m. and it wouldn't start in the p.m. Without warning the 12 volt battery died.....it did survive 60,000+ miles.

 

Just experienced this yesterday evening (after the car had sat in the garage for 5 nights). I tried the turn-off-immediately trick, and when I turned it back on, it only rattled for a few seconds. Earlier this year I had it happen and it lasted for a good long 30 seconds...which really worried me. It sounds awful.

Interestingly, it happened again this morning. I've never experienced it happening twice in a 24-hour period.

Time to call Toyota. Thanks for the info on the TSB!!

 

Oops, I guess I'm out of luck...we have over 80K on our 2010. So...other options? Seems like the replacement IM doesn't always fix the issue (not surprising). Water in the fuel sounds plausible.

What I want to know is...WHAT EXACTLY IS RATTLING? Anyone know? I mean, it's a horrific sound...something has to be whacking against something else pretty hard to make that sound. Also, after my wife pulled the car out of the garage this morning (after it rattled for about 10 seconds), it did smell pretty "rich". I don't recall smelling this on mornings it doesn't rattle.

Ugh.

 

I would still report it to the dealership anyway. You never know what they will do for you. If nothing else, you have a paper trail in case of a class-action.

 

Yup.....me too!....& for the "Theory" that it's only an annoyance..... no damage is occurring while this "Hammering" is taking place.....simply wishful thinking....IMHO

 

Doing a little experiment for a couple weeks. Going to run "supreme" 91 octane gas for a few tanks and stick to the same shell station in that time. All other driving habits will stay the same. I noticed the knocking on startup happening 2-3 days in a row when I got home from a long road trip a few weeks ago. Maybe picked up some bad gas(water contaminated) along the way.
Read in another thread the prius seems to be picky with gas contamination and does not tolerate it very well.
I probably won't keep using 91 past a couple tanks (kinda expensive)but from now on will be more cautious on which gas stations I fill up at, I understand busy, clean gas stations are the best as there is faster turnover rate of the gas in the storage tanks, so less chance for water to accumulate.

All just speculation, but figure doesn't hurt to try something different see if it changes anything. All starts have been smooth and rattle free so far since the switch.
My next service appointment I will definitely bring up the issue, hopefully enough voices will get toyota to do something, at least to explain what is happening.

The worst part is, even if it is not harming the engine at all it can't be good sales promotion for the prius when everyone looks around the parking lot to see what's making the horrible knocking sound, oh it's a prius, what a piece of crap!

 

Take it to your dealer and show them the service bulletin and tell them to make a service ticket for the problem. (2010 Service Bulletin) Let them know dealers are starting to see the issue in 2012s....... An employee of the dealership I use had the issue in his 2012 so the problem is starting to show up. The dealership changed the intake manifold on the employees 2012 just like they did for my 2010.)

Also, I think there is an octane requirement that is less than the 91 octane you should stay with. Using 91 gives them a good reason to blame it on now following the manual.

I did bring the dealers eyes "to attention" when I announced to them that a Prius sounding like a Diesel truck being started in a Mall parking lot won't help their sales out!

 

Page 116 of the prius v manual: "Use unleaded gasoline.(octane rating 87 or higher)"
Absolutely no harm in using higher octane. The ECU can easily adjust for the less "knock-prone" fuel. On the other hand a lower octane fuel than 87 would be out of the question and would probably destroy the engine.
Only harm done using 91 octane is to your wallet, which is why i'll be switching back to 87 after this tank.
(as a side note, i also decided to try 91 octane as its the only fuel with 0% ethanol available in the area, 87 contains 10%, though even if it did improve fuel economy slightly i don't think the price per liter difference is worth it)

 

Thanks!

 

Good day. Sorry for my English. I have the same problems. Manifest at every start after long-term Parking. His Prius 2010 I bought in Germany and moved to Russia. Not one dealer Toyota is not replace the intake manifold. So I want to replace himself. How do I buy the correct intake manifold 17120-37052? I am afraid that I will sell 17120-37051 or 17120-37050. Show photo of how they differ.

 

I did a little experiment to prove that the knocking is basically a noisy misfiring.

The video is posted on youtube:

Here are my comments from the video: