Rough engine start

i have also gotten the shake rattle and role 2 times

 

I did something similar today with mine. I needed to move the Prius a foot or 2 to make room in the driveway. Then about an 2 hrs. later when the ambient temp was about 60ºF, I needed to make a run to the store and upon starting the engine, it made an awful noise in the engine compartment. Lated a second or two then drove normally, but with the ICE running, which I thought was odd because I was only going around 5 mph.

I'll watch it to see if it happens again.

 

I have an 08 Prius so I have been told it has over 200,000km
the speedometer's been replaced

I had a unusual knocking noise at starting and low idles mostly.
Check Engine light would flash and stay on.
scanner kept saying 3rd cylinder

Changed the Plugs changed the coils
did a compression test

Same problem same code

Changed the Fuel injectors Problem solved!!!

 

My 2010 Prius V with 10,500 miles exhibited this "Rough Engine Start" for the first time after not being used for two days. The temp. in the garage was 50 degrees F. at the time. Has anyone succesfully found a fix for this through their Toyota dealer?

 

Not that I know of, at least no one has posted a dealer fix here. It's an intermittent problem and dealers don't don't do very well unless they can walk out the the parking lot and see or hear the problem.

It appears that it only happens after the car cools down for several hours and then only after it has been run for only a very short time before shutdown. That is just to much information and to many conditions for most dealership mechanics to absorb. They will simply go out to the parking lot start your car, come back in and say "it seems OK to me".

Some posters have gotten a dealership to keep the car overnight but of course that doesn't mean the problem will occur. Even if you manage to convince them there really is a problem they are not going to know what it is.

So far all we have is a few guesses by PriusChat posters involving fuel, ignition, lubrication, cam timing, etc.

EDIT: I should have added that there are some very good mechanics and technicians at Toyota dealerships and I intend no disrespect to them. A few post on this site and their input is of considerable value to us.

 

Has anyone found a sure-fire way to cause the shaking starting from a cold engine? Like on, then off, then on, etc.?

If we had a way to replicate it, we could use that at the dealership to:

a) Show them the problem reproducibly, and let them get the codes.
or
b) Go in and pretend to be interested in a car, replicate the problem, then say we don't want a car like that. That would probably get their attention better.

My concern is that Toyota's fix for the cars in North Dakota, will be to tell that dealership to go out and warm them all up each morning.

 

I've also had this rough engine start but only when outside temp is low and my solution to this is to put my foot on the brake and shift in to reverse "R",stops the shake rattle and well no roll...because i have my foot on the brake!!I do this until there's some engine temp and it works for me..so maybe give it a go!!

 

Unfortunately no one has found a way to cause it intentionally, at least not as far as I know.

I do have a "work around" that I use to make it stop. A bit different than the one posted above by Halpos4.

I leave it in Park and when it starts shaking I put the gas pedal clear to the floor. This increases the RPM by a couple of hundred and it smooths right out. Now when I start it while cold I push the gas to the floor as soon at the ready light comes on which starts the ICE, as soon as it starts I let off of it. I haven't had the problem since doing that. Maybe just a coincidence or maybe it works.

 

My 2010 Prius has 20,000 miles & just started to do this, a couple of times in the past few days. The post above about "hogging" sounds like BS to me--this sound is like an engine problem, not a alternator/starter problem. It could be the collapsed hydraulic lifter mentioned above, I am not enough of a mechanic to recognize that sound. If so, I would think it might be related to the exceptionally low viscosity oil we use.

In any case, it does sound like something that could shorten the engine life and needs to be addressed by Toyota!

 

Our dealer here in Muncie said they have seen this event with other vehicles. I have to assume they and the Prius have the same basic ICE. The service writer said they have also seen evidence that it's related to the quality of gasoline, but I'm having a hard time buying that. I've had engines run poorly and get bad mileage with bad gas, but how far out of spec would gas have to be to cause THIS?

Our dealer could not duplicate the event so they sent me on my way after checking everything else.

I haven't had this happen for quite a while, and it's been plenty cold...

 

Happened to me the first time this morning (~15 000 km, -8c). Scared the crap out of me. I instantly shut down and started recording a clip to see if it would do it again and sure enough it did.

[ame=http://www.youtube.com/watch?v=nJJaMTyN-Ao]YouTube - Gen3 Prius Rough Start[/ame]

I tried the accelerator trick mentioned before, but it did nothing (why would it? The engine doesn't respond to pedal input when the car is in P).

Going in for service next week anyway so I'll certainly mention it to them at that time. Disappointing.

-Iain

 

Apparently the "accelerator trick" does not work on all cars. It does work for me and I have used it about 4 or 5 times.

The car definitely responds to throttle input while in park, you should actually try it before posting that it does not. The RPM will increase several by hundred when you put your foot down. I just tried it and when the car is warmed up RPM will increase to over 2500 in Park if you hold your foot down. When the engine is cold and the "shaking" phenomena starts a quick jab on the accelerator increasing engine speed from it's normal 1280 cold idle to about 1500 does the trick for me.

I am not sure why this works. Some have speculated that when the RPM increases it also advances the timing a little; others have said that the problem is due to left over unburned fuel which causes it to run rich and the extra air from a quick throttle jab leans it out. I don't know if either theory is correct but I do know it works for my car and it works every time.

 

But why would it do anything? The accelerator in the Prius is just an input telling the car "I would like to go faster". When you're in P, you can't go anywhere, so logically it must ignore the input. It's not like a conventional car where it directly corelates to engine power or a "throttle".

-Iain

 

Perhaps it works that way for test purposes? I'm not a Prius Technician or a professional mechanic. I do know after changing oil, for example, it's nice to be able to start the engine in Park and let it run at a fast idle for a minute or so to check for leaks.

Edit: You can also hold the brake down and floor the throttle in Drive and the RPM will increase, this can be use to "force charge" the hybrid battery. This won't work in Park but it will work fine in Drive. Since the car does not have a transmission with torque converter and clutches that slip it shouldn't hurt anything.

 

Wow, that sounds really horrible. Was there a solid or flashing check engine light while this was going on?

 

This sounds like a loose timing chain hitting things to me. I've heard that sound before, usually on aged cars though. The newer Corolla has had timing tensioner leak problems, I read somewhere. This fits with the noise, oil leaks down out of the tensioner, or the tensioner is not able to build enough oil pressure under certain conditions. That's my 2 c. on it.

 

Loose timing chain? Good lord, that would result in all sorts of havoc, would it not? It wouldn't take much slack for it to slip a tooth on the sprocket...

I can't imagine it would be that. How is tensioning of the timing chain facilitated? Is it not a spring-loaded UHMW slider? I thought that's what most engines used...

-Iain

 

This has happened to me twice. Once this past summer after sitting overnight and again last week after sitting in my garage for a week or so. The exhaust smelled very rich until the engine began to run smoothly (about 15 seconds). Ambient temperature doesn't seem to be a factor, nor does the amount of time the car sits between starts. Im concerned that at some point in the future, I'll have some serious engine problems as a result of these hard starts. I've mentioned it to the dealer who can find no codes and claims that Im the first one to ever have this problem!

 

IIRC Toyota has eliminated the timing chain in gen 3 Prius.

 

It would need to use a belt, gears, or a chain to drive the cam shafts, I think it uses a chain.

You can buy one from this site for about $150, hopefully we won't need to because it should last for a long time. http://www.dealerdirectparts.com/2010-TOYOTA-PRIUS-Engine-Timing-Chain-p/toyota-6123146-prius-4.htm