If the only noise that you have now is from 35 to 46 mph, more than likely what you are hearing is the high pitched sound emanating from MG1 and MG2. At that speed range you are +/- 5 to 6 mph from the maximum all electric speed the car is capable of. At those speed ranges, MG1 can be turning several thousand rpm depending upon engine load and whether or not you are in regenerative braking.

To understand how MG1, the engine and MG2 relate to each other and how MG1's speed can vary depending upon the load, take a look at this example from an earlier generation Prius:

Prius Power Split Device

The planetary gear set that the PSD uses is very similar to those in an automatic transmission in a normal car and is the heart of the Synergy System. They run in an oil bath (Toyota claims this is a "lifetime" fluid...yeh, right.......) and use a splash lube system to stay oiled and cooled.

If a bearing was going out, the noise would tend to vary in pitch and always be there at any speed (there are exceptions to that but not often). If you have access to a lift, you can have someone run the car at speed and listen with a stethoscope from underneath to pinpoint the noise.

 

This could be the cause of the humming. One way to test is when you hear the humming between 35 and 46 mph, listen carefully to what happens if you take your foot off the gas pedal. If it is the humming from MG1 and MG2, the noise should suddenly stop or at least get very quiet when you take your foot off of the gas pedal.

The MG1 and MG2 humming is normal, but more often is described as a whine due to the higher pitch of the noise.

 

I went back to OAK LAWN Toyota, in oak lawn, IL. THE WORST PLACE EVER.

The techs still couldnt figure out what the noise was. After an hour of their technician snooping around their middle ****ING MAN ERICK. Came by and took me to my car where he showed me my car open and telling me that the hub bearing is not making any noise. Then he tells me that he took the car on a ride with the technician and (AFTER AN HOUR) HE SAYS THAT NOW THEY CANT HEAR ANYTHING.


WHY THE F**CK WOULD YOU PUT THE CAR ON JACK AND WASTE MY TIME IF YOU THINK THAT YOU CANT HEAR ANYTHING.

AFTER THAT THE GUY SAYS THAT IF I WANTED TO PROCEDE ANY FURTHER I WOULD HAVE TO PAY MORE.

(I AM LIKE) HOLLY **** I AM PAYING YOU FOR DIAGNOSTIC AND NOW YOU ARE ASKING ME FOR MORE AFTER YOU CANT FIGURE OUT WITH ALL OF YOUR ****ING DATABASE OF PICTURES, SOUND DIAGNOSTIC, TOYOTA COMPUTER, AND NOT SAYING THE EXPERIANCE IN DEALING WITH THE SAME CARS EVERYDAY. YOU CANT FIGURE THIS OUT AFTER 2 HOURS NOW THAT YOUR 2 OF YOUR TECHS HAVE SPEND ON THE CAR. **I DONT KNOW HOW MORE MONEY FOR YOUR COMPANY WILL AUTOMATICALLY POP UP THE SOLUTION. (****ING *** HOLES)

I followed the guy inside, i asked the guy to take a ride with me and i can point out the noise. now the guy says that their is a little noise, but its barely noticeable. The guy says ok! After two minutes the guy comes out, avoids any contact with me, and gets busy and starts calling people on the phone. When i stand their for 20 minutes right infront of him. The guy mumbles something to his co-worker, takes his jacket, and F**king walks out the door. I wait their for another 15 minutes for the guy and his co-worker calls me to him, tells me that i should not waste my time with them and go through my insurance company instead.

NOW tell me what the f**k kind of service is that. These idiots are nothing more than f**king oil changers, filter changer, and button pushing robbers.



I then walk out the dealership get in to my car and drive to my dads mechanic. He takes my car for a drive and tells me that he wants to check the alignment.

After checking he tells me that the back alignment is off, after he fixes the alignment and he takes me for a drive. THE F**king noise is almost gone.

Their is still a little bit of the roaring noise left at 35-46. I haven't driven it above 50 yet but the noise is only noticable to me because i know what to listen for and when to listen for it.


*** F**uck you OAK LAWN TOYOTA (****ING ROBING DUMB ASSES)***


THANK YOU VERY MUCH EVERYONE FOR YOUR HELP ON THIS I REALLY APPRECIATE IT.

 

Glad you found a honest, good mechanic. Their are those that are in it for the money and then they are many talented mechanics. Evidently the guy or guys that supposedly worked on your car are not very thorough on locating hard to find problems.

I see you bought the new goodyear fuel saver tires. Could be their so new they may make a slight noise for a months worth of driving then they should quieten down. You might try 35 to 38 psi when the tires are cool.

 

I have a 07 Camry Hybrid with a very similiar problem. But my car has 140,000 miles and new tires. The hum began about 10,000 miles ago. I brought it to the dealer and they said they THOUGHT is was a front end wheel bearing and said it would cost $1,000 to replace both front end bearings (they will not do only one). Does a worn out wheel bearing make a hum?

The hum begins at about 40mph but and kind of fades out at 65. Maybe with the road noise I just can't hear it at 65? It sounds very similiar to driving a car with snow tires on it. It is very hard to tell where the noise is coming from. All the tires are inflated properly, wearing evenly and the noise doesn't change when the tires are rotated.

The car performs perfectly otherwise. Do I invest $1,000 in a car with 140,000 miles when I not confident the the bearings are not the real culprit?

 

DennyD,

Run, don't walk away from that dealer. Replacing the bearings on both sides should run (factory OEM prices) $300 for the bearings and $280 to $300 in labor. Go to your friendly neighborhood mechanic and buy Timkin bearings for $160 and pay $225 or so in labor (at $75 an hour) and get by with less than $400. It is only a 2.8 hour job so 3 hours maximum is what you should pay for.

If the entire hub needs to be replaced, the parts will cost more (about $250 or so aftermarket price) but the labor price will drop by about 1/2 as they do not need to press the bearings into and out of the hub.

 

I had a similar humming noise at those speeds when I was driving my '94 Corolla. It like to drove me crazy and over a year it got louder.

The humming which seemed to come from everywhere became a louder roaring sort of sound when I accelerated or went up any grade. The corolla had around 155,000 miles on it at the time. A good toyota mechanic I called on the phone, said for me to check for slack in the cv-joints. I had no popping sounds at all when turning a corner at slow speeds.

I located a axle shop here in town and stopped in so they could have a look. The owner had hurt his back and could do no work. He did put my car up on the rack to show me something. He took a drop light and showed me how the inner-cv joints had slung out the grease over time. He said both inners were dry, even though both boots looked good. I paid him some for his effort and left.

He said with that many miles it would be best to replace both half-shafts. I asked would they be new ones from toyota. I found he used rebuilt axles. I came home and choose buy rebuilt ones from R-Axles in Florida. I bought both half-shafts for about $295 exchange. This was 2003 prices and I replaced both myself. That eliminated any humming or roar under load when driving.

I would highly suggest that if your problem is a cv joint to buy a brand new toyota half shaft. I found what may be new half shafts from metrotoyotapartsnow.com/ I know nothing about this company. They do have a very good price if these are toyota parts. They show pricing around $450 for the short shaft and $550 for the longer one.

I doubt this is your problem with your 55k low miles, but may be worth looking into. I see where David had already mention checking the cv boots out.

 

Read this TSB. t-sb-0106-08 Vibration .pdf

Hello to all. I've been lurking for a while. I just purchased my 08 TCH and have just replaced the tires to eliminate them as a cause of my 60-80 MPH vibration. I purchased Michelin Primacy and had them road-force balanced. Now the next step is to go to the dealer armed with this TSB. I'm hoping for the best. Aleaxander Toyota in Franklin, TN has been very good to me so far. They replaced my defective Homelink and JBL CD-changer just before going out of the 3-36 warranty.

 

If you have a strong vibration or "flutter" in the steering wheel or can feel a vibration in the floor pan at 65 to 75 mph, this TSB might apply. The OP has a "humming" noise at 35 to 45 mph. After having his tires replaced, I still think the remaining noise is coming from MG1/MG2 as part of the normal operation of the car. It might still be a mechanical issue (bearing, CV joint, etc) but once those are ruled out, I would suggest a ride in another Camry HV with similar mileage (or more) on the same roads to see if the sounds are similar between the two vehicles.

 

Whille the subject line is certainly not exactly the same as the TSB he did speak to the issue in the TSB.

Here was the OP's statement regarding the 65-75 MPH vibration form one of his earlier posts:

I think the Hub/Wheel bearing issue that is spoken to in the TSB is not a deal where a technician can easily perfrom a test to find the problem. In fact the TSB states that if you rule out the normal things like run-out and balance then Toyota has determined that manufacturing tolerances were a problem before a certain serial number on certain cars. Therefore owners are entiitled to this repair under the drive train warranty to restore drivabiltiy. This is a situation where a good dealer will work to help a customer or drive away a frustrated customer. I think it's worth a shot if the OP has done due diligence to eliminate the run-out and balance issues but still has the problem to put this TSB in front of the service manager for additional discussion.
One of the problems with some dealers is that they will go out of their way to avoid doing warranty work. You have to be diligent and work through the process and escalate until it's fixed.
GH, you are dead on in saying that the the TCH has drivability querks that take getting used to. The transition from motor to generator and back sometimes can be felt by the driver and can be mis-understood. I'm still getting used to these characteristics. Thanks for your input.