Engine Knocking (twice) at Startup - Anyone Else Experience?

I have a 2010 prius and i have had this violent shaking and knocking twice on start ups in the morning. If you go to the other thread linked in this thread there is a video that shows exactly what happened to me.

I have 18K miles on mine and it has happend twice, both in cold weather.

Dealer couldn't replicate, so they didn't do anything. Said they hadn't heard of the issue nor had Toyota.

I have seen enough folks on this site having the same problem I would hope that Toyota would be more proactive.

I'm not pleased that a new car has issues like this.

 

Happened to me today. Pri had been sitting in an unheated garage for about a week without being driven, altho I had started up 2x and ran until ICE shut itself down. It's about 20deg in there.....
Not really a knocking sound, but more like a bunch of bolts being shaken inside a large coffee can.
The car did not shake or anything, but it scared the @$&^^$ out of me.

I listened for 2~3 seconds then shut it down.
Gathered myself and fired Pri back up. I could just detect the same sound trying to manifest itself, but it didn't and the car started smoothly.
2 things I noticed...
Before the ICE kicked in, I heard a distinct low-grade 'click-click-click' coming from somewhere...same as if the battery was dead in a 'normal' ICE set-up. I heard this same sound both times when I fired the car up in the past week...but in those cases ICE started smoothly with no other noises. I've never noticed this sound before... &
There was no clicking or otherwise when I re-started today.
Took Pri around for ~10mi spin after re-start and all was normal...
I just came back from repeating the start and warm up and everything is fine...........

 

My 2010 Prius IV is garage kept. I have owned it since 7/15/2009 and it has less than 5K miles. All maintenance is up to date and preformed by my Toyota dealer. No problems until today.
When I started my car (after being parked overnight, garage temp abt 40 degrees) today I heard what sounded more like a metal-on-metal clunking than a traditional knock. It scared the hell out of me so I shut everything down immediately. I opened the hood, expecting to find something stuck in the engine, and had my wife start the car. Same thing happened. I was about to call a tow truck but decided to try to locate the problem once moreI. I then put a drop light in the engine compartment and had her start again while I searched for anything unusual. The racket rapidly decreased to normal engine noise.

I took the car to the dealer and by that time it was running normally. They kept it overnight and couldn't duplicate the problem. No error codes were evident and a "Health Check" didn't find anything wrong. Next time I'll be prepared and record the sound on my phone.

If that noise is caused by moving parts not getting oil until the engine is running for a few seconds the life expectancy of the engine will be greatly diminished.

PLEASE DO NOT settle for "They all do that". If you're hearing what I heard there is most likely something significantly wrong with your car.

 

His post indicated that his "Check Engine" light did come on - different from most of the other posts re rough start. Looks like his problem, at least, is solved.

 

Yes! Happened to me. I had about 5K miles on mine, in the garage after a cold January night (perhaps 40 in the garage). Cold start and same sounds. I got out of the car right away after popping the hood. Opened it and the knocking sounds were definitely from the "Electric" side of the front end. I quickly went back in the car to shut it down - and was terrified... On restart it was fine and has not happened since.

I checked on the forum for 'knocking sounds', but nothing - so thought it was a fluke. Sure appears not. I read all the posts incl the coil and "normal". If it was a coil, one would think it would recur. And it sure isn't normal (give me a break...).

I plan to mention it my next service visit / recall trip, simply to get it on my record.

I really don't think that any of us that experience this issue should sit on our thumbs - what's the best way to escalate?

 

During the warranty period, "They all do that" is the most common diagnosis.

Immediately after the warranty period ends this changes to, "You will need to take care of this or it could do serious damage to your engine. We will have to replace the digital discombobulator immediately. A new one is $900 but it could do thousands of dollars damage to your engine if you do nothing".

 

So, I took my car in to another Toyota dealer to have them check and doccument the engine knocking problem. I let them have the car for a week while I was out of town. They looked on day 2 of having the car and couldn't replicate the problem. I went to pick the car up, still unhappy that the problem hadn't been fixed. The service manager said, I will go out to the car with you and see if I can hear it. I cranked it, and what do you know, KNOCKING like a cummings diesel under the hood. Did it for about 15-30 seconds and then normal. So, at this point I'm glad the service manager was able to verify it, but even more happy because I think I've got it figured out. I thought it was cold weather that caused the severe knocking, but I now think it is when the car sits for 4 or 5 days. Of course, anyone taking their car to the dealership woudln't tell them to let it sit for 4 days, but see if it happens to you after this period of sitting. It happended to me.

I took the car back to the dealer, they have now had it for 15 days and said they had never seen anything like this. They contacted Toytota engineers and followed some test they told them to perform and NOTHING.

Bottom line is that the engine has severe shacking and knocking during some start ups and it hasn't been fixed yet. So, when i try to sell the car and someone asks, "had any problems", I will tell them about this problem and say it can't be fixed. I don't think I will be able to sell the car for market prices under those conditions, so I expect Toyota to fix the problem one way or another.

There are enough folks that have had the same problem they should figure it out.

So, bottom line, let you car sit for 4 or 5 days, crank it, then see if you get the extreme vibrations and knocking.

Thought it may help those out there with a legitmate problem like me. I'm not pleased at this point, but I do hope Toyota can figure something out.

 

Proactive? HAHA

I bet if each one of us goes to a different dealer they will all say the same thing. If we called Toyota USA or GB or Europe they will say the same thing too. Don't believe me? Give it a try.
They will say this is the first thing they ever heard of and you should take it to your dealer so that they can take a look at it. And then once you are at the dealer they will say the same thing and then they will look at it and can't reproduce the problem and then just make you feel like you are an idiot.

This has happened to me 3 times. First time it was so violent that I was terrifed thought the engine was about to burst open and lasted about 5 seconds.

2nd time it happened it was not as bad at first and this time I was prepared for it and had my foot on the brake pedal so the car would not jerk back and forth as much.

3rd time it happened I thought the engine is going to break. Not break as in burst open this time but thought the chain was coming off. Why? Because it sounded like the chan was lose and the engine was going to stall but after about 3-4 seconds of that it went back to normal.

I really don't know if this is normal or not or if this will damage the engine. I've changed my filter twice already and didn't see any debris in the filter to suggest the engine had been chiped or damaged in anyway.

One thing I do notice is that it might be very possible to replicate this problem. Start your car, let the engine come on and then shut the car off completely after it comes on for about 5 seconds. You will notice that when it shuts off it shakes a bit. Then you do that for the seond time and shut off the engine after turning it on for about 5 seconds. When you turn you car on again for the thrid time thats when something weird happens. If you like to experiment then you can try this at home. If your engine does fail, not to worry we are all covered under warranty.

 

happened to me a while back as well, took it to the stealership and they told me its because I had put premium fuel in it... but being a trained technician myself, I know that putting premium fuel ina brand new car is not going to cause its engine to convulse like an epileptic.

 

I had this once ages ago in the middle of winter. Reported it to the dealers at the 10k service and they mentioned something about dodgy coil packs or something like that.

Not sure if they checked and/or replaced a coil pack under warranty, but the knocking has never happened again since.

 

If they had replaced the item then it will be noted in your invoice.

 

Well they replaced the drivers wiper and wiper arm under warranty and they didn't show on the invoice.

 

Don't know. If they changed anything they would let you know unless they broke something without you knowing.

 

Had the same thing happen to me this morning. My car has about 6k on it. Scares my kids to death. Shut it down and restart and back to normal. Going document it with my service dept.

 

I won't say anything other then Toyota is more then likely NOT going to help us with this issue. We as a community are going to have to figure this out.

 

Quick search found this youtube video from Dec 09, ouch!

YouTube - 2010 Prius Engine Knocking


Since 'cold' starts are the problem, guessing the relatively thicker oil has something amiss.
http://www.techno-fandom.org/~hobbit/cars/training/800/vvti.gif
I don't understand how this works, glad it (usually) does.

edit; related link, dealer possible fix.
http://priuschat.com/forums/gen-iii...nocking-noise-startup-there-may-hope-yet.html

 

toyotech spoke to our FTS for our region (CAT) about this issue. No dealers have reported this issue through a DPR (dealer product report) or likewise as they are unaware of this issue. He did say that if I can replicate it in my car (its happened once) that they would allow me to take Techstream (our Toyota scantool) home and set it to record the rough engine start (knocking issue) and see what is going on and develope a fix for it. I'm trying my best guys

 

After listening to the YouTube video posted above, my guess is that incorrect variable intake timing is causing the rough engine start. It's got to be either intake valve timing or ignition timing... In either case, engine ECU firmware would have to be revised.

It would be very interesting to see what Techstream shows, if you can replicate the issue on your car.