2010 Prius running very roughly

That seems the smoking gun. First off, you might check the condition of the hybrid battery fan. @NutzAboutBolts has a video on that, pinned at the top of 3rd gen maintenance forum. The fan can get clogged with lint or hair.

The only comment I'd have on that video is that it's not necessary to remove the rear seat: if you push open a gap between the rear seat and back, directly below the fan inlet grill on seat back, there's a single 12 mm (socket size) bolt in there that you need to remove. It can be done with a ratchet with maybe 9" of extension. You can squeeze a hand in there while removing the bolt, to catch the bolt, you don't want to drop it.

You also need to pull up the forwardmost portion of the rear hatch floor (with stubborn fasteners, most of which I left off at reinstall), peal back a few velcro carpet bits, a few more bolts and plastic fasteners. It's not that hard, follow the video. Also, you can clean the fan without complete removal. Helps to have compressed air of some sort, even a wet dry vacuum on blow, or a leaf blower, for example.

All that said, if the problem is not just the fan, would it still be under warranty? The service department will likely not budge until you have a trouble light, some code(s). But get in touch with them, see what's what. Maybe drop $75 or so on a diagnostic session, especially if it it's still warranty, if it turns out to be the hybrid battery.

 

Have you checked the oil level?

 

clean the egr system

 

If oil was changed by jiffylube or similar, I'd check the dip stick ASAP to see if it's over filled.

If this is the first time ever running rough, I'd drain their engine oil just put in and re-change it myself or have another shop do it. They have idiots working at those convenience oil change places. It might be that they put in conventional oil in or overfilled.

 

Maybe a bit early to be this, but rough idle might point to EGR clogging as well. Theres a good video on this by @NutzAboutBolts , pinned on maintenance sub-forum. Ultimately I found OxyClean was best , for cleaning the EGR cooler.

Note the mention rough idle:

 

Wish I new about this Toyota notice , left work recently.. was at drive through eating a burger. 2010 Prius all options, 200K miles , turning on an off at idle while I was eating ( typical of hybrid), outside temp about 60 after I experience rough start ( 1st time ever) and engine light came on..., Finished burger and immediately drove a few miles to my office with car running smooth and went back to work. After work car start was rough, engine light came on.. drove home car ran smooth, predominantly highway, dropped at dealer, they diagnosed the next day ( EGR and Intake manifold, repair was approximately $1100.) Upon pick up, dealer said his last experience indicated that problem could re-appear and if it does in his experience it would be transmission which would be $4000 to replace, Said he heard a noise in transmission and could be converter or clutch??. I asked why not replace just that? he said they do not do transmission work they just replace whole thing . Anyway ,car ran fine at pick up . I then took to another mom and pop repair that specializes in hybrids for second look, he said no issues or codes. Anyway car ran OK until, two weeks later when I am driving, and, turning off street,( stopping at turn.. engine turns off typical of hybrid) then after turn and proceeding up a small ( 60 degree incline) rough start upon engine start up . It smooth's out , however ,similar incidents over the next week. Anyway I do not have time to play twenty questions and start looking for a car ( find one after two weeks , 2014 camry hybrid) . Anyway over that two week period similar instances ( rough starts on some hills) then at some stops while driving. However after rough starts car runs fine. Anyway traded in car ( got $3200). Just thought I would pass this along as I always enjoyed the forum. Never ever had any other issues with this car aside from routine tire replacement and brake pads ( $395 front back dealer installed guaranteed for life) . Also hit a pot hole a year ago and blew out tire. Ultimately had leaky strut . Did not repair but estimates for two fronts ( strut and spring were) : dealer $650, Seaxrs -$750, PBoys $900, 3 local small shops were $875, &900 and 1000 ( respectively) . Anyway always enjoyed this forum and thought I would share my experience. My questions are is there tubing or hose that connect to egr or intake that should also be changed or cleaned during this type of repair as I asked for old parts and did not see any tube or hose in the box. Also can transmission issues cause rough starts??

 

EGR system is steel/aluminum, from the exhaust manifold connection to the connect at intake manifold.

So the car is gone now?

 

Bad 12 volt battery?

 

yes traded in for a 2014 camry

 

You first state the Prius had 69,000 miles and then you state it had 200,000 miles on it. Which is it?

 

I think the first place you took your car to that said it could be the transmission, were just trying their luck. The guy said they don't work on transmission? Heheheheh. That was a plot to let you leave in a hurry.

ANYWAYS, glad you got another car though.

ANYWAYS, was there any light lit on the instrument cluster? If there was, do you have any scanned results?

ANYWAYS, I think when the problem resurfaced after some weeks, that shows, the problem wasn't tackled.

ANYWAYS, other things such as a clogged injectors, dirty fuel pump strainer, spark plugs, etc.

ANYWAYS, I'd expect you keep spending more time on PC, just like I do, to learn more about these kinda problems.

Dxta

 

Did that fix the car, or ....?

 

LRW and hyb are of 2 different person