new Prius smells like something's burning

The "B" on the gear joy stick is to use in such situation. It will use the gas engine to brake to relief all the work from the pads.

 

By any chance, did you have the steering wheel turned into one direction for a very long time?

I remember in the manual about the electric steering that it could overheat if you hold it in one direction for a long time. Considering you were going down along a path, I doubt that is the issue.

 

Don't know about the burning.

But when the climate control is in auto it defaults with the AC on (no matter what temp. you have set) While the climate control is in Auto, you can go to the climate screen and touch the A/C button to turn the Air Conditioner off but still maintain automatic climate control.

 

I was also wondering about that AC light. In most cars, it means the AC compressor is running, which would be a waste if you're running the heater. I suspect (hope) the system is smart enough to shut that down when not needed even though the indicator remains lit.

As for the burning smell, I experienced that as well on the second day I had the car. I was on the freeway on level terrain. The smell was very brief and hasn't returned since. Nothing seemed amiss, so until I saw this post, I had concluded that perhaps it was coming from the car ahead of me. It could have been some sort of factory coating burning off something, as you said. I'm not too worried.

 

Actually I had this happen as well, I just got my Prius. I think the smell was the tires. Mine went away after less than 100 miles though. I'm pretty sure it is the tires because confidentially I also just had new tires put on an older vehicle and I got the same smell. Call it tire burn in...

 

I, too, suspect brake pads even if you used "B". This happened to me when descending a big slow dirt road downhill (~25 minutes downhill at 10-20 MPH, battery way on green after less than 5 minutes even with "B") while visiting friends in CA last summer. I really wouldn't worry unless it recurs in different situation. Once the battery's completely charged, you use those brake pads MUCH more than you would normally.

 

First: the A/C compressor is electric. It is run off the HV system and only runs when the ECU decides it needs to. Therefore, setting the temp to the highest comfortable temp will result in the best fuel economy.

Second: unfortunately, smooth shutdown of the ICE is not always accomplished, I believe it is due to a slight dieseling effect of the engine still trying to run even though the ECU has shut off the fuel, possibly MG2 not quite disengaging quickly enough or maybe the engine stops at a point where the cylinders have enough compression left to cause the crankshaft to move a half a revolution or so. It's just an opinion and a best educated guess. However, it is common and is not dangerous.

Third: the burning smell may very well have been from other cars, or it may have been trash/foreign object on the catalytic convertor. I see a LOT of that. Plastic bags stuck on the cat and melted into a rock solid blob which must be chipped off and the residue allowed to burn off.

 

It's not a waste if you're running the heater; ok maybe the heater, but not with the defroster and heater. You'll find the defroster works better because the air is still being dehumidified when the compressor runs.

Bear68 has a good point - dieseling of the engine will occasionally occur. I just noticed it happened once to my car a couple days ago in perfect conditions. But I have a funny feeling you were riding the brakes all the way down that hill, causing the nasty smell. What are the two nasty automotive smells that seem to cook up more frequently on slopes? Clutch and brake. And with no clutch, per se, it has to be brakes.

~ dan ~

 

yesterday, after six days of driving the car i finally gave it the foot fr a block or two and the smell showed up, good thing was that aftee that it ran much more efficient

 

Quite true with a conventional car but not a Prius. The mechanical brake pads do not touch the rotors unless you are under 9 MPH or in a panic stop situation. Riding brakes on a downslope just adds to regen. This will lead to the so called "dieseling effect" when the ICE is being turned to lower the SOC of the HV battery after heavy regen.

 

Was this the first time you drove the car that long and far? It sounds to me like the shipping coating finally burned off the exhaust manifold. I have had the same thing happen on other Japan-built cars I bought new. After several hundred miles, the coating finally gives up the ghost and quickly burns off with a strong chemical odor. Perfectly normal.

 

You're gonna have to prove that to me using documentation. I refuse to believe there is no mechanical link between the brake pedal and the hydraulic brakes. Why else would they work when the car is off?

~ dan ~

 

Take a look at the lost front brakes completely thread. Post 24 by Jayman contains two attachments which diagram how the Prius brakes system works. My understanding is that a fail safe mode assures that a solenoid valve in the brake actuator opens, when necessary, to secure hydraulic fluid passage between the master cylinder and the wheel cylinder.

 

I believe that when OFF the car is traveling less than 9 MPH. There is plenty of documentation on the Prius Brake System , the search feature will help.

 

Thank you. That explains the process. Even still, you don't think that enough downhill slope will engage the brakes? I mean I can't believe the car wouldn't know better than to let you overheat the inverter fluid...

The correct way to respond to a request for documentation is to honor it. The minute you demand that others seek out support for *your* argument is the minute you lose all credibility.

Thanks, IsrAmeri. It seems from this chart that the vehicle diverts pressure to the brakes when the MG* system isn't applying enough braking energy. I would imagine that there are more events than a "panic stop" that would require direct braking energy; but I am not a Prius engineer. At least the schematics shed some light.

~ dan ~

 

After about 6000 miles, my 2007 Prius Touring model started smelling as if a plastic bag was melting on the muffler. It seemed to happen when I used the auto climate control to warm the passenger compartment. The smell was also evident from outside. I just opened the hood, found, and removed many leaves. Could this have been the problem?
Thusly

 

My wife's 2005 Prius did this for a couple of weeks, but my Prius, bougth 6 months earlier, did not. To me, it smelled just like the smell of burning plastic spoons; a smell I remember well from my Boy Scout camping days. It mostly went away after about a week, which was about how long I was going to give it before taking it back to the dealer. It was completely gone after a couple of weeks.