2010 Prius Vibration at Mid-Throttle

Usually a rear wheel bearing is not affected by changes in throttle input. It will usually be pretty constant rumbling. My first thoughts would be tire separation or something of that nature. Remember , the rear wheels are not subject to anything but weight. The just roll. The front wheels are a different matter. They have torque applied under throttle. With that being said, I would first, check your tires by lifting the off the ground and rotate them to see if you have any anomalies in the tread.

 

If it is a specific speed it usually is the tires. Since you think it is coming from the rear passenger side, swap the rear tires to see if it improves. I find bad tires shake the least if it is placed at the rear driver side.

Also winters almost here, you can just wait to see if it still shakes after you mount your winter tires. If you can't wait that long, then try mounting your 2 winter tires at the rear and see if it eliminates the shaking. I've run winter tires at the rear for 2 years straight thru summer and they never got destroyed.

 

When you first described the symptoms one of my other thoughts was that it might be related to engine misfire, i.e. spark plug coil, or injector malfunction. However, something like that would probably trigger the MIL light to come on. However, you never know.
At this point you may have no other alternative but to take it in and have it diagnosed at the dealer.

 

I noticed a very minor buzz at mid-throttle with ours, seemed to be coming from behind the glove box. Push a little harder, or less, it went away. This was 2~3 years back, haven't noticed it at all since. It didn't seem to be a dash rattle though, seemed mechanical.

 

Gonna bet you need to clean EGR ports the entire length of the intake manifold and the pipe from the manifold to the EGR valve. Although I may be wrong, I'm betting you're mistaking this "misfiring" for a vibration. This problem can get quite disconcerting and never throw a code as I can attest. Cleaning as stated fixes it. It involves some digging but is not a technically advanced procedure so long as you possess some mechanical inclination.

Prius III engine knocking at high torque low RPM (solved) | PriusChat

 

khoda355 here has finally taken the whole EGR system off for cleaning. He says the component right at the beginning, next to the exhaust manifold was really badly clogged. And a bear to do.

Not just another p0401.. PICS! | PriusChat

 

I'm guessing the P0401 guys have an issue at the EGR valve itself or in the exhaust side plumbing as per khoda's excellent photo documentary. They aren't necessarily reporting the missing at high-torque, low rpm issue. Thus my thinking that it's the clogged intake manifold and pipe to EGR side that's causing the missing and without code. This is somewhat backed up by khoda stating that the intake side cleaning did not rectify P0401. Either way, it's another of those very frustrating, seemingly widespread issues which Toyota is playing dumb about. And to think (at least I think) that of all the major auto brands, Toyota is most willing to own their issues...

 

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Hi there, welcome to the club Sounds exactly like my Prius 2010' problem with 55K miles on it. We had another thread in August this year 'Prius shuddering on slow acceleration', where RudeBoiM3 described the same problem with another 2010 (!) Prius, you can check that thread as well. RudeBoiM3 was able to fix his problem, mine is still there. Prius doesn't throw any codes. I've done some DIY stuff myself: changed spar. plugs, ignition coils, PCV valve, put newer model intake manifold, changed ATF, cleaned throttle body, etc. Plan to work on EGR system and injectors when have time, currently running on tank of gas with Seafoam in it. Hopefully, I will be able to fix the problem before it's time to trade-in

 

sorry i replied to you.
mental note to myself: never reply to jerks who use racial slurs as their user names.

 

My dad had a great mechanic who diagnosed a bad rear transaxle by noting the "shaking in the seat" feeling you describe. Of course it was an older rear-wheel drive with a regular differential. I assume you've done this, but you could jack each rear wheel, grasp it in the nine and three o'clock position and try to rock it pulling on one side and pushing on the other. Do the same at the six and twelve o'clock position - there should be no play at all. Back at the 3 and 9 postions, try lifting the tire and releasing...again there should be no bearing play.

 

Any time! Those good days are gone, now we need 2 manuals instead of 1: one for electrical, another for mechanical
Well, so far my DIYs didn't help much, but there is still some hope. It happens in the 'low RPM-high torque' range, and this is the moment when EGR valve starts to open. My Torque app tells EGR is opened between 15-25% at that moment, so I suspect something could be wrong with the EGR system. To rule it out I am going to disconnect EGR valve cable and test drive. In this scenario valve will never open, so if problem is still there, that means EGR is not the culprit, and vice versa. I will have to clear check engine code afterwards, but this could save me a lot of time if EGR is OK. Planning for this weekend if I have time.