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

gen 2 had a rubber bladder inside the metal gas tank. for pollution reasons. but it never worked very well.

 

Both of Mine have not done it in a long time. Odd! Wonder if it was done on secret recall on a service visit.

 

Got an extended warranty for the knocking issue and EGR valve in the mail. 150K

 

Also got the Warranty Enhancement Notification ZF3

 

Just got the ZF3 notice today. Does this make the intake manifold fix unneccessary or are both repairs recommended?

I reported the knocking to my dealer back in 2012 but never got the manifold replaced since they didn't have it in stock. The knocking was hard to reproduce and seemed to go away after a year.

 

Hello,
I just have the same problem , my engine is knocking at ~ 50km/h
With dig tool i found misfire at cylinder 4 but without any MIL or DTC set.
To check that you need to go to monitor data and check the misfire data. DO NOT TURN THE IGN OFF.
So after I change the ignition coil and spark plug the misfire still present on cylinder 4.
The next step: I exchange the injector form cylinder 4 with cylinder 1 and cleat all data.
Run the engine again (drive test) and read the misfire data form data monitor.
Misfire at cylinder 1.
Today I take all 4 injector and try to clean up with (local service - using ultrasonic waves and test it)
I will keep you informed with the result.

 

Sounds like your EGR is clogged.

 

Hello,
I just was informed by the service that 1 injector is below threshold. And by the way I clean up EGR , and intake. To test the EGR if working proper I insert a small metal sheet to block the egr pipe. No effect.

 

This is a long outstanding issue(Engine knocking on start-up, especially in winter) on the Prius III 2010-2015, and mine has been doin this since 2011 but seldom but always if the engine started and did not allow it to complete the cooling cycle, like when moving into garage from driveway (Short distance). Sad, when you take it to dealer problem could not be repeated. But since this 2016 winter (May-date), the problem got worse, every morning, and also whenever the engine restart at robot the engine will shutter, causing the safe clutch on the hybrid system to knock vigorously (often scary).

Been to dealer and they wanted to open the hybrid transmission to find out the knock. I went and did all the test by myself, and find out that the actually knock happens in the hybrid system due to misfire of the petrol engine, the knock is when the build-in clutch inside the transmission protects M1 motor against misfiring petrol engine.
Cylinder 1 misfire
Using my OBDII scanner tool, I detected a misfire on cylinder one every time this happens but the car OBD did not and will not through a "check Engine" light.
The cause?
I used an inspection camera, put it through the cylinder in the morning, and found higher moisture than normal(Compared to other three cylinders). Overnight, this caused the cars to puff just whites smoke with smell of a burning coolant.
Key fault
I can now with confidence tell the forum that the cause of all this misery is the failed top gasket, and not the inlet manifold, in fact Toyota retracted that call and in my country (South Africa) has never been issued.
My local dealership in Pretoria has done all test and quoted between R18 000- 22 000) for top gasket repair, and I was scared of going to independent service centres since the Prius is not common car here, and was worried that the gasket repair will lead to other petrol engine problems during stripping and resembling
Solution
I looked at all gasket fix liquids, and many had graphite like content which will often result in blocking the interior heater system and most importantly the thermostat, but this product I got (South African developed) is pure liquid, no need to remove thermostat and it worked, is not 7 weeks/9400km, the problem is gone. I am still trying to get my mechanic to give me more information on it and has cost me less than a R1000.00
Now my 2010 Prius Gen III is back to its normal running, the cold knocking is over, gone. Amazing indeed!
Conclusion
Although the Prius are beautiful cars to own, I think Toyota messed up on this one, the top gasket is actually the culprit, and unfortunately in my country to get a recall will never happen (unlike US) but these is the problem (Top gasket failure) not the inlet manifold, or any of the electrical parts like the spark plug, or the ignition coil.

 

Back with news:
The problem on my car was fix and generated by 2 issue :
1 - Injector on cylinder 4 stuffy
2 - EGR valve. I order a new EGR valve with 120 code ( the update form TOYOTA)
Until NEW EGR will arrive, I block the pipe with a small metal plate. No my engine is running very smooth without any knocking and no misfire. Hope this week.
Regards,
Alex.

 

Hello
Yesterday the egr valve was replace with the new one. All are ok now .
Everything is ok now.
Alex.

 

Got a letter stating they will extend my warranty for this issue until next year. Has anyone else received a letter from Toyota?

 

Yup - Got the letter last week.

 

I have.

SM-N930V ?

 

The other day I was shuffling cars around, between driveway and garage. Without fail I manage to move the Prius without starting up. I'll start up, slap it in reverse, move some while counting, and shut down around the count of 10. Repeat as required to get where I need to go, because EV mode is pretty much always on a sabbatical.

Well except the other day I messed up, engine fired up, for maybe 2 seconds. Then this morning, I started up for real, and got the knocking, not violent, but noticeable. Shut down, restarted, everything back to normal.

 

I live in Vermont and bought my 2011 Prius Three back in February. To my knowledge, the knocking has never happened. If I go to my dealer and request this service, will they do it as preventative maintenance under the warranty, or does the knocking have to happen first?

 

Need the code to display and be repeatable at the dealer. It's written in the letter.

 

I had the knocking first start at 20k it has never completely gone away but Its no where as loud and crazy knocking as it was. However I have used alot of fuel injector cleaner cause people claim its clocked injectors. I honestly think it could be caused by to much blow by and that oil sitting in the intake manifold. When I clean that out and my car starts it so smooth. After a while when that liquid is back in the intake it tends to have that knock. Just my observation. I am gonna invest in a catch can and hope that helps fix the problem.

 

Just wanted to add a note we got a good overnight cold spell in the eastcoast and I got the knocking longer than before.
I did not add my HEET treatment or techron in the fuel tank like I have done in the pass to keep this away.

I quickly turned it off and restarted and it went back to normal.

my2cents

 

I have been getting this engine knocking occasionally in cold days for the past few years. Since it doesn't throw an engine code, the dealer probably won't even know where to start the repair. I've also been watching this thread for years. Toyota must have known of this issue but still refuse to acknowledge the problem or issue any fix or recall. I am hoping Motswaledi from South Africa can tell us more about his solution soon. For now, I am sitting nerveously everyday and hope the engine won't blow because I plan to keep it at least another two years.