Transaxle hum but no warning lights.....help???

Re: Scangauge Loaner in Los Angeles

Hum is not good. That usually reflects a bad mg. Also you would see much higher cvt temp caused by the bad mg. You could check that with a new Xgauge. It might be worth it to buy an xgauge as there very handy to have. If I lived in LA I would stop by but I'm in Fla.
But a failed mg would also throw a slew of codes too. Odd.
Because its not throwing any codes are you sure the sound is coming out of the trans and not a wheel bearing. Wheel bearing failure is pretty common on this car. I lost my LF wheel bearing at 30K and it made a humming wup wup noise at 40 and above.

And do you see any cvt fluid leaking out where the axles come out of the trans as those seals leak right there sometimes.
Check fluid level asap to get that out of the way.

Btw, have you owned this car since new and or never been in a wreck?

 

Re: Scangauge Loaner in Los Angeles

Thats not looking good. Please see this thread:

http://priuschat.com/forums/gen-ii-...ne-speed-red-triangle-vsc-warning-lights.html

 

Re: Scangauge Loaner in Los Angeles

Seen that mentioned before here and its basicly gibberish.

I own a Scangauge so am partial to that. Here's a list of codes available with the new Scangauge II:

http://www.scangauge.com/support/toyota-specific/

 

Mate seriously with these cars, until It aint broken, DONT fix it...!

wait for the issue to get worser, & lights to pop up, that will show the problem...

the best you could have done you done already by changing the transaxal fluid...

 

Good. Monitor cvt temps like that thread I linked. Trans on these cars run pretty cool. The bad mg will spike hot like 180F.

CV joints especially inners don't hum when they fail but
hum is subjective but not sure what your asking is there a joint inside the trans that may be servicable? Doesn't matter you can't get any parts for it and you would have to pull the cvt anyway. At that point there's used cvt's available.

But are the inner & outer rubber cvt boots intact and not ripped or leaking?

And with no codes thrown its a head scratcher at this point.

 

The joint that goes into the transaxle is a very basic tri joint that doesnt usually give problems. I have had gen 2 prius do over 500,000km and give no trouble with the inner joint. The outer joints closest to the wheel have failed but they give a very distinct clicking sound when turning.
If the mg temps are ok the bearing under the silent chain is failing. Early on it wont set any codes but as it gets worse they will light up.
This is very common here in Cairns in the taxis.

 

Once again, are you sure it's not a wheel bearing? That's a very common cause of humming in that area.

Tom

 

Drive somewhere that you can make turns at speed. Get up to the speed where the hum is audible, then turn to one side and then the other. The turns should be sharp enough to generate noticeable side loading. A bad wheel bearing will be louder turning one direction, and quieter the other.

Tom

 

Qbee is on it as thats how the Toy tech road tested it. Parking lot not neccessary. Drive down a quiet road and whip the wheel a little back and forth one direction then the other slowly. Like your avoiding a road hazard. If the noise gets louder as you whip it, it's the wheel your whipping into.

The WB would make the most sense 'cause if its a shorted MG it would throw codes.

I lost my LF WB at 30K on my 07. Fixed under 3/30.

 

Interesting. Is anyone rebuilding the transmissions up there Shane, or are just fitting new ones?

 

Laying under a car while its running... yikes. Someone had to say it.
If all tests for the wheel bearing seem negative, I would try draining the the transaxle fluid into a clean container , you can reinstall the fluid, after checking for the amount of metal on the magnetic drain plug, and also whatever shavings settles into your catch container. It may give a clue in the inside of the transaxle.
I've considered doing this to my car halfway between fluid 'changes', filtering the transaxle fluid through a fresh coffee filter, and reinstalling it , as the car itself doesn't have a fluid filter.
.