CLICK & CLACK’S CAR TALK

LITTLE ROCK — DEAR TOM AND RAY:

I’m sure you have seen the Viagra commercial on TV in which the intrepid driver notices that his muscle car is overheating. He swings into a service station, buys a cold bottle of water and immediately pours it into his radiator, then drives merrily on his way. I’m just an old schoolmarm, so maybe my information is out of date. But I was always told: (1) Never even try to take the radiator cap off of a hot radiator. It could blow scalding steam in your face. (2) Never put water in an overheated engine, as you could crack the block. (3) When you add water, start the motor before you pour anything into the radiator so that it circulates. If I’m right, and the guy in the advertisement is wrong, then ED is the least of his problems. Please comment!

- Chrissy

RAY:

You’re right, Chrissy. On most cars, if he popped off the radiator cap while the car was overheating, he’d have second-degree burns all over his face and arms. And no amount of Viagra is going help him.

TOM:

In general, you never, ever should remove a radiator cap while an engine is hot. Especially if the car is overheating. You want to give it a good 45 minutes to an hour to cool down, and then, still, open it very slowly, using a large rag for hand and arm protection.

RAY:

Unless you have a car with a separate, unpressurized coolant-recovery bottle. Then you can remove that cap right away. The 1969 Camaro used in that ad may have been one of the last cars to have one of those. So you’re right, Chrissy,but this particular car is an exception to the rule.

TOM:

Normally you would wait until the engine cools before removing the cap. So you wouldn’t add any fluid to the radiator when the engine is red hot, either. Adding cold water to an overheated engine can potentially damage the block.

RAY:

But with an unpressurized recovery bottle, you can add fluid anytime, because it sits in the recovery bottle and gets sucked into the cooling system later, when the engine cools.

TOM:

On most cars, you would wait until the engine cooled before adding cold water. That’s why old-timers suggest you run the engine - so the cold water circulates and mixes with the hot immediately.

RAY:

In reality, once the engine is cool enough to safely remove the radiator cap, you can pour in cold water without fear of damaging the block. So running the engine while adding fluid is unnecessary.

TOM:

But here’s where Romeo went wrong: Adding a 1-pint bottle of Fiji water is unlikely to solve his problem. It’s not enough water to make a difference if he’s really overheating, and more importantly, it doesn’t solve the problem that led to the overheating in the first place (probably a leak, a stuck thermostat or a pluggedradiator).

RAY:

So if the commercial continued for another three minutes, he’d be overheating again. Not as much as he’ll be overheating from Viagra, but overheating nonetheless.

DEAR TOM AND RAY:

I was ticketed recently for not stopping at a stop sign. I was sure I stopped. When I questioned the officer, he said all four wheels have to stop. The implication was that one or more of my wheels stopped and the others didn’t. Is this possible?

- Linda

RAY:

Not unless Congress amended the laws of physics, Linda. If a car were out of control and skidding, it’s possible that one or more wheels could lock up, while the others would continue to turn. But I doubt that’s how you approached this stop sign, or the officer would have given you a citation for reckless driving, too.

TOM:

My guess is that the police officer meant to say that all four wheels have to come to a stop behind the white “stop line.” It may be you didn’t stop in time, and your front two wheels went beyond the line. That makes more sense.

RAY:

But if you have time, you can go to traffic court and ask him to explain how one or more of your wheels stopped and the others didn’t. It might get a laugh from the judge, and he might reduce your fine. Or he might double your fine for being a wiseacre. Good luck.

Click & Clack (Tom and Ray Magliozzi) dispense advice about cars in Car Talk every Saturday. Email Click & Clack by visiting

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