I did a search for my problem on here and couldn't find anything. 2008 prius. When I go above 20 miles an hour I hear a winding noise like its stuck in low gear .. Sounds like transmission or electric motor. Drives fine without loss of power. The noise started on the way to target and when I came back to my car the check engine light was on. codes C1249 and P0420. The codes don't sound like something that would cause this noise. The faster you go the worse it gets. Coasting does it to (let off accelerator). Does it with or without gasoline motor running. I had grooves in my front rotors so I replaced them and the breaks. NO change except the motor stayed off longer but I could have been trying to find something different but it seemed like the motor ran more before the rotor change and I thought the rotors could have caused some drag but not sure. Around 45 mph your pretty sure you shouldn't drive it until its fixed. I didn't check the transmission fluid because there is no dip stick. No other warning lights are on. Car seems to run fine just the loud whinning noise like a electric motor or low gear. Doesn't drive like its in low gear just sounds like it is. Please help
I just listened to a youtube video of a prius that they said had bad wheel bearings. It sounded a lot like ours, could that be it?
It’s got 170000 miles it’s going to start needing a lot of things. 420 is most likely bad cat probably the engine eats lot of oil and contaminated it. Pretty common. And yeah you gave a bad wheel bearing And a soft 12 volt battery. If it’s got the original hybrid battery keep that in mind too.
How are you decoding codes? What are you using? Some OBD devices do not do full hybrid decoding. You may not be harvesting all the codes. Buy a Mini VCI off amazon runs on an xp laptop it has full Toyota tech stream software can analyze anything and full hybrid battery decoding. $25. But a mechanical issue like you have will not throw a code till it immobilizes the car. I suspect its the chain in the trans based on all the thrashing I hear. But there is a bearing that sometimes fails in the trans also. very rare on this site. Lusciousgarage.com discuss it on there service blogs. Car has been punished or somethings happened to the trans fluid. Start swinging at it. Change the trans fluid it will tell you if its in the trans.
