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

I wonder if the timing chain has a hydraulic tensioner controlled by oil pressure. To me sounded a lot like chain slap/slack. But as advanced as these engines are, it may be a more high tech reason like above.

 

I was added to the engine knocking last friday and called the dealer and they said, come on down, I took it in today and talk to there prius (expert), Well I describe the problem, and offered to let him see and listen to a viedo that was on this web site that show him what I was talking about. His standard anwser was that it was normal operation of the car, I told him he was mistaken,

 

Welcome to the club Waldo. I had it happen two times to me early on (last fall) but has not happen since.

 

Talk to the Prius technician at Corwin Toyota in Fargo, ND. 800-377-0177. Toyota engineers came to the Corwin facility and examined 15 2010's on their lot, 11 of which shook violently when started in cold weather. They connected a special computer to one of these to collect data.

At this writing (see date of post) I've been told there is internal disagrement between the body and engine groups as to whether the problem is caused by the Gen 3 motor mounts or the computerized fuel system.

My 2010 shook so violenty at -26F as to spill my coffee. it had been parked in a parking lot for 6 hours after being throughly warmed by a 100 mile drive. For the first minute or so it sounded as if it had a broken connecting rod. I believe it was running on two cylinders. Then the shaking subsided a bit and I believe a third cylinder started firing. At this point I put it in drive and limped to where I was to pick up my passengers. It had very little power.

Very shortly after picking up my passengers I believe the 4th cylinder began firing. The shaking subsided.

This occured a couple more times when the temperature was below zero F. It was after this incident that I first called Corwin to make an appointment, knowing it would be very cold the next morning. They told me not to bother because they had plenty of cars on their lot doing the same thing.

Other ND and MN dealerships have experienced this problem wth cars they are trying to show. It must be tough showing a car to a prospective customer only to have it shake violently when started.

I'm not exaggerating when I describe this shaking as violent. The Corwin technician said the fuel line wouldn't break (starting a fire) but I worry all this shaking and knocking is doing long-term damage.

 

I have had this problem twice. I have a 2010 Type II and the first time it happened in February. I live in the south and it was about 50 degrees. Second time in June when it was about 85 degrees. I would actually describe it as a roaring sound-worried that it was going to damage so turned off vehicle first time and turned it back on to have it happen again. Second time when I shut engine off and turned back on, it was a quiet start. Took it to dealer and of course, couldn't replicate even after leaving overnight. Service manager said he investigated and Toyota has had no reports of anything like this. Uh huh...but at least it's documented so hope when Toyota owns up to anything, it's on record...

 

I just had this violent shaking happen to me this morning.

2010 Toyota Prius II with about 1600 miles on the odometer.

Haven't driven the car since last Thursday (been sitting in the garage for about 3 days without being started.)

The car shook violently and threw a MIL. Took it to the dealership and they pulled a P0300 (multiple cylinder misfires). No answers from the dealership and I've owned the car for about a month......

Need some answers....


-Sam in Kansas

 

work around

Try this it works for me, when the shaking and banging starts instead of pushing the Power Button to shut the engine off just push the throttle to the floor. The slight change in engine speed smooths the engine right out.

Note pushing the throttle to the floor when you are in park does not cause the engine speed to increase by much so you won't over rev the engine or anything, it only increases by a few hundred RPM.

No guarantee but as I said it has worked for me several times and a couple of other posters have tried it and it worked for them also.

 

Re: work around

I wouldn't mind the rough idle on occasion if I leave the car off for several days, but it caused the "check engine" light to come on. I absolutely do NOT want to have the car malfunctioning enough to tell me to take it to the dealership, but have the dealership tell me they have no answer to fix it.

I was doing a little thinking and I wonder if it has something to do with vacuum? I was trying to think of something that may last day to day, but not last for several days. Vacuum pressure in the lines comes to mind. I wonder what would happen if I pulled a vacuum line tonight and let it sit all night in the garage, put it back on in the morning, and try to start it?

Anyone else want to try?

-Sam

 

Good idea, some more things to check:
http://www.random-misfire.com/
http://www.underhoodservice.com/Article/40008/diagnostic_dilemmas_the_misfire_code_as_a_symptom.aspx
OBD-II Trouble Code: P0300 Random/Multiple Cylinder Misfire Detected

If I were to bet I would bet on some Prius developing too lean conditions on start up. Maybe the software should be changed to rich the mixture some in cold weather starts?

 

Well, it's a good thing Toyota is finally analyzing the situation. You know, could this be something to do with the fuel used in some parts of the US? There are soooooooo many Gen IIIs in Los Angeles (where Toyota HQ is) that if the cars here were doing it on LA gas, they would know about it.

Perhaps injectors are getting jammed for a little while after being parked. The strange thing is any kind of misfire will cause a code to be stored... and most people don't get codes. Mysterious....

 

Re: work around

I not only pushed on the pedal, I drove the car about 200 yards. The shaking stopped two or three minutes after I stopped to pick up passengers. During that short drive it had very little power, as if it was running on two or three cylinders.

 

Re: work around

Thanks for the information, apparently my work around doesn't work every time for every Prius. Did you push it clear to the floor? mine has always stopped shaking within a second of when I floor it. Seemed changing the amount of fuel and air going in was all it took, but maybe not. I have never had it go on for that long either, if I did nothing it always smoothed itself out within 10 to 15 seconds.

Here are two rough start threads with polls, it might be helpful if those who have the problem visit these threads and take the polls.

http://priuschat.com/forums/gen-iii...shooting/84911-zvw30-rough-engine-starts.html

http://priuschat.com/forums/gen-iii...4959-zvw30-rough-engine-starts-companion.html

 

It was -26F when this occurred. All of my violent shaking incidents. and all of those experienced by the Fargo dealership, have occurred in sub-zero temps. That dealership filmed one of these events.

 

20k miles and the rough engine start/knocking sound happened to me for the first time last night. I had moved the car earlier in the day from my driveway into the garage. The ICE ran for less then a minute. Several hours latter, 30F temp, I remote started the car and got the infamous rough start with the knocking. I was walking away from the car when it began, as I made my way to the car it began to idle smoothly. Freaked me out! Not good to see your fairly new car almost shaking itself to death.

I’m calling my dealership today, I expect the typical “we’ve never heard of this before”.

 

Having same issue. Bought the car in Aug 2010 and engine knocking happened 3x during cold weather at about 20 degrees. Emailed Toyota and they advised to bring to dealership and also notified the National Highway Safety Administration. So I suggest those having same problem should call or email the National Highway Safety Administration so they know many cars it's affecting and investigate the issue. I scheduled a service appointment with Toyota in 2 weeks and will let you know if they resolve the issue (hope they do and not tell me that they can't duplicate issue).

 

bounce88, did you move or start your car for short periods before you got the engine nock?

 

Ya I experienced the same knocking ... running ruff ... no power when I depressed the Accelerator. This happened twice - under 50 degrees F.

I turned off the vehicle then re-started (no wait time to speak of) and the problem / ruff engine / knocking was righted.

Still not sure how to repeat the situation nor the root-cause. I have a 2010 with 22,000 miles of flawless miles on the vehicle to date.

I will keep you posted ... assuming It occurs again.

Mr. Bill

 

36k miles and never a noise. I have ran 0-20 Amsoil pure synthetic since 2K miles.

 

I first recorded hard knocking a year ago and reported it to Toyota with no resolution to date.

 

Could it be the same problem afflicting the Prius?

http://www.empirepao.com/tsb/T-SB-0087-09.pdf

The TSB talks about a video of the problem but link isn't working...