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

Yea, the issue is due to the misfire caused by the inproper fuel/air mix when condensation and/or oil is added to the cylinder.

If you've got a situation where there is more water in the cylinder than space in the combustion chamber, you've got a bent rod.

 

Umm all you have to do to create a misfire is liquid in the spark plugs gap.

Pixel XL ?

 

Almost posted that myself but thought it will eventually get poo pooed on.

 

Didn't say “a bit of condensation” on my end, let alone provided quantity of condensation

 

Maybe I missed it - is there a post in this thread discussing the differences between the original intake manifold and the newer updated ones?

 

You can searching for it

 

I tried, but with no luck. There was even a discussion about the updated intake manifold didn't really solve the startup knock/shake - which is good to know - I won't search it out.

 

Focus!

(I know, it's tough.)

 

Since you tried to search... I’ve seen post from long ago that even when the part was updated under TSB, the knock returned. My best guess is that the head gasket may have packed it’s suitcase before the updated part was put in. I have a refreshed model, it knocked in cold weather winters w/o an OCC so I can vouch that update Intake manifold didn’t fix anything.

 

Yeah I suspect removing/cleaning/reinstalling the existing manifold works about the same as replacement with the revised one.

 

check your EGR cooler for blockage. i learned it hard way with blown head gasket. i replaced head gasket and cleaned fully clogged EGR cooler and the knock has not come back since even though it was around 46 degrees this morning and last week we had 39 degree morning.

 

Mendel,

Thanks. I have tried one small bottle of the Techron cleaner (black one) and am getting ready for another bottle due to needing a new fill-up very soon. The first bottle did bring my mpg to roughly 32.5 until I then went and added 2 gallons of gasoline to postpone filling up for a few days. Since those 2 gallons near empty, it got up to 37.8 mpg but dripped to 36.5 (1 bar of gasoline left). So here’s hoping tomorrow after another fuel cleaner and a full fill-up, that it gets even higher mpg again.

I hoping this Covid mess is over with before reaching 100k miles for maintenance time. I really would like to get all done at that time for ease and money sakes.


Thanks to everyone else, too.

Stay safe and healthy!


iPhone ?

 

I had my intake manifold replaced out of pocket in February after the dealer told me I needed to replace it. Any chance I could get that cash refunded ? It was like a thousand dollars.

 

Google the number for Toyota customer service. They have an extended TSB. I believe the mileage limit is 150,000 miles

 

Bell,
Your Prius still at a pretty low mileage; your frustration with the low mpg makes sense, having gone through the same issue myself.
There are relatively low cost solutions depending on what your car needs. I just had a 2011 Prius with 200k miles on it, before I got done with it, I had replaced a few things that got it back up to 50 mpg.
List of parts costs (some of these might not be relevant to the issue your car is having)

- can of sensor cleaning $5
- (4) original spark plugs $13 (ebay)
- (4) fuel injectors $40 (ebay)
- fuel pump $80 (local parts puller)

Just want to show you from my experience that it is possible to maintain and fix any issue you have on the Prius on a budget. Mainly I’d like to see if you have any pending codes, to see what actually “needs” replacing, because that low mpg does indicate some underlying issue. I’m assuming you aren’t pushing it in power mode all the time haha

 

I had this happen to me this year on an extremely cold day - about 10 degrees at start-up. That's not a sound I want to hear again. I shut the car down in less than 2 seconds. Waited 10 minutes and tried again - it started and ran fine the second time and the problem hasn't reoccurred.

Mine is a 2015 and I noticed the TSB only covers 2010-2011. Not sure why they didn't cover all the Gen 3's.

 

because yours got the updated parts at the factory. they don't work, toyota has never figured it out.

hopefully gen 4...

 

I second what bisco said. Even Non 2015 turd gens that got the revised part still suffered engine knocking. Either way, engine condensation will rear it’s ugly head and cause the knock. What you need is an OCC, mine havent knocked since it was installed 3 years ago, even in 20F weather.

 

My Gen.4 "Rattles" upon startup (I wouldn't call it a "Knock").......short, with no mis-fire.......probably an oil/pressure thing......