Cold temps freeze auto locks on van

Dear Car Talk:

Our 2008 Hyundai Entourage van, which we purchased new, has always had electric door locks that will not function in cold weather. Not sure of the exact temperature, but once winter rolls around, we have to manually unlock the doors; we can't open the locks with the remote. I took it to the dealer when this first occurred, and got some mumbo-jumbo but no solution. I should have been more persistent, but now it is too late. Other than buying warm gloves, do you have any suggestions? – David

RAY: How 'bout a heated garage?

Actually, you’re lucky that you can’t open the doors, David. A lot of Entourage owners from the 2008 era complained that their sliding rear doors would open on their own – sometimes at highway speeds! I think Hyundai tried to convince those owners that was part of the “James Bond” package.

As for your door locks, there are several possibilities. One is that the linkage itself is getting frozen. Moisture is always present inside the doors, since those cavities are not airtight. So that moisture could be freezing the linkage that connects the “locking button” on the inside of your door to the lock mechanism itself.

Is it difficult to unlock the car manually? Or do you see the locks “straining” to open when you press “unlock”? If so, that suggests that the problem is mechanical; perhaps a bound-up or frozen linkage.

In that case, you can have someone remove the inside door panels and spray the linkage with a desiccant, like WD-40. You can try it on one door first, to see if it helps.

Another possibility is that the problem is electronic, and the signal to each door’s unlocking motor (solenoid) is not getting through. That could be because of a bad connection somewhere that opens up only in cold weather. We know that wires, like everything else, shrink when they get cold, right, David? If you don’t believe things shrink when they get cold, check the next time you go swimming in the ocean.

So it could be a random wiring or connection problem, or there also could be something wrong with the body-control module, which is a computer that operates things like the power door locks.

If absolutely nothing happens when you hit the “unlock” button, and you can manually unlock the doors with no more effort than usual, that would suggest that something more central and electronic is causing the problem.

If it’s mechanical, it’s probably worth trying to fix. If it’s electronic (and there were a number of issues with this vehicle’s electronics), you’ll have to decide if you’re willing to pay a mechanic to try to track it down. And then compare that expense to the cost of a heated garage. Good luck, David.

Larger wheels have both advantages and disadvantages

Dear Car Talk:

A buddy of mine just bought a new Lexus ES 350, and he ordered it with 19-inch wheels. Is there an advantage to having larger wheels on a car? – Wayne

RAY: Well, most people think they look cooler. I think that's the prime motivating factor.

They do also improve handling. Generally speaking, the opening for the wheel-and-tire combination (the wheel well) is only so large. So when you use a larger wheel, you usually pair it with a tire that has a shorter sidewall.

Tires with short sidewalls are called “low-profile” tires. And when you turn, those low-profile tires have less sidewall that can flex. That makes the car’s turning response a little sharper.

So if you have a car that’s not known for its sharp handling – like a Lexus ES 350, or a Lincoln Navigator – you can improve the handling a bit by getting larger wheels and having sidewalls that flex less.

The downside is that those low-profile tires degrade your ride quality. All that extra sidewall, with its greater flexibility, helps soak up bumps and road imperfections, which softens your ride. So it’s a trade-off.

Now, on a car that is designed to have a very soft ride, like the Lexus ES, you might have room to accept a slightly firmer ride in exchange for better handling. It’s likely the ride still will be pretty darned comfortable.

But on cars that already have firm rides, you’d probably be better off going for the standard wheel size with the larger-sidewall tires.

The other downside of tires with short sidewalls is that it’s easier for the tire and the wheel to get damaged by potholes or curb stones that you drive over.

And if you think those optional 19-inch wheels were expensive when you bought the car, wait until you start having to replace them along with your 19-inch tires.

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