I have an 07 TCH with about 70k on it.

I got new tires put on, and suddenly the car is significantly louder. Its not road noise, Multiple people have noticed even when the car is idling.

It sounds like it is in too low of a gear (I know doesn't make sense with CVT), or its revving too much, or like its being driven in B mode.

I took it to the dealership and they said nothing is wrong and it sounded fine, but its very noticeable to me and other people. I am tempted to go back in and make them test drive one right next to it so we can compare.

When in E mode, it is completely silent, so I am confident it isn't road noise, or anything like that, its definitely from the engine.

Is there any way to reset it? Or what could be loose/missing?

I had driven the car briefly (20 min) in B mode the day I had the tires changed as well due to downhill in snowy conditions, could it some how be stuck in B mode in software?

 

The car manual may state, not to drive the car while in the Brake Mode. Best to use the brake mode for gearing down rather steep hills, like a 17% grade here up in the mountains. Then I use mine at speed around 20 to 30 mph. Lesser downgrades I ease on the brakes when approaching curves, so the regenerative brakes to operate.

When in the brake mode, it uses regenerative braking, some engine gearing down and your physical brakes to help slow the car.

I do know you can hold the car at speed using the gas peddle but could cause wear on the physical brakes.

About the engine noise - you may need to find out how they lifted your car to put on the tires. I doubt they could lift under the engine area to mess up a motor mount. Under the engine radiator area are plastic type air deflectors to help reduce turbulence and increase your miles per gallon. Just a thoughts as I had some worn motor mounts that was causing a older engine to sound louder. Were talking 150,000 miles here on a '94 Toyota Corolla.

Any possibility their lift moved the muffler mounts to case some noise from it though the car body.

You might take it to the tire shop and tell them about the engine noise starting after they put on the tires. If they might have a look to see if their lift might have somehow caused this new noise to happen.

 

There is a baffle in the muffler that reduces exhaust back-pressure when throttle opening is greater. The baffle is probably stuck open thus resulting in increased noise levels.

 

The increase in engine exhaust noise is rather noticeable when the baffle opens in the muffler. I suspect this to be the issue. Try putting it in neutral while the engine is running, set your parking brake and go to the back and listen. You should be able to tell. Normally the idle exhaust noise is extremely quiet.

As far as driving in Brake (B mode) I often drive 55mph in B when coasting down a 7% grade near me. The grade is about a mile long, and it really saves the brakes. Other than the engine reving a bit, there is no increase in exhaust noise.

 

I am due for an oil change. I will take it into the dealer this time and have them investigate the baffle.

 

Can you provide an update? Did the tire guys break your exhaust when they lifted the car?