I’m sure you guys can think of other questions or information about “spy cameras” in rental vehicles. Thanks. — Bill
Bill: You know the stuff that they had to shovel off city streets back when people traveled by horses? Well, that’s what this story is.
I remember when the internet first emerged, thinking that it could be a great educational tool for all mankind — providing all the world’s knowledge at everyone’s fingertips. Instead, it provides all the world’s knowledge, along with a forum for every knucklehead with a paranoid imagination to find like-minded knuckleheads and spread nonsense.
OK, let’s go back to cars now and leave the philosophizing to “Hints from Heloise.” There’s no truth to this, Bill. If a rental car company secretly recorded a customer, they’d be breaking all kinds of laws, state and federal.
There’s no equipment in the car that comes from the manufacturer that would enable a rental car company to do this. And no respectable rental car company would ever install such equipment. There’s simply no benefit to the rental car company. And the risks are enormous, from criminal liability to international embarrassment, to the loss of their customers.
So, rest assured, Bill, whatever you were talking about in your last rental car, neither your boss, nor — maybe more importantly — your spouse, has a recording of it. As long as that snoopy Alexa wasn’t listening.
Dear Car Talk: My 12-year-old Prius V hybrid makes a loud rattling sound when I start the car and then when I accelerate. It does go away after driving awhile.
The Toyota dealer has said that it is because the car is switching from EV to gasoline engine mode. Is this normal? Is there a way to get rid of the rattle? People on the street can hear it!
Thank you for your help. — Jane
Jane: Well, I’ll give you two answers, Jane: a happy answer and a sad answer.
The sad answer is that you could have a leaky head gasket. That could make your gasoline engine run rough at first. And a rough-running engine will make everything around it rattle.
That would be sad, indeed, especially for your bank account. But I don’t think that’s what’s going on. It’s more likely that the noise is coming from your exhaust system.
All gas-powered cars have catalytic converters. And because those converters get red hot, each one has a heat shield around it — top and bottom. The heat shield is just a thin sheet of metal mounted a few centimeters away from the converter itself.
It’s there to prevent you from setting your car on fire if you park over some tall grass or a pile of dried leaves. Although a fire would definitely solve your rattle problem, Jane.
Anyway, as cars get older — and your 12-year-old Prius qualifies — the rivets that hold the heat shield in place can fail or corrode. When that happens, that thin sheet of metal will vibrate — against the converter itself or whatever it used to be attached to. That causes — what? — a buzzing or rattling sound.
And as the metal parts heat up, they expand and touch each other, and that often causes the rattle to stop after you’ve been driving a while. But it’ll always be most noticeable when you start the car first thing in the morning, when everything is cold.
If it’s not the heat shield, another part of the exhaust system could behave the same way. If you have a broken exhaust hanger, for instance, that could also allow the exhaust pipe to rattle against the undercarriage, especially when the car is cold.
So, I’d leave the car with your mechanic overnight. If he starts it when it’s ice-cold, he’ll hear the rattle. And he’ll know instantly whether it’s an engine noise or an exhaust noise.
If he sends you flowers and a card, you’ll know it’s not an exhaust noise. Good luck, Jane.
Got a question about cars? Write to Ray in care of King Features, 628 Virginia Drive, Orlando, FL 32803, or email by visiting the Car Talk website at www.cartalk.com.