Dear Tom and Ray:
I drive a 1984 Ford Tempo. The heat shield fell off my car in traffic, and I was not able to retrieve it. I am told that I cannot have another one attached. Is this true? What are the consequences of driving without a heat shield?RAY: Well, Suzanne, we'll answer your second question first. The heat shield is a thin piece of metal that wraps around the catalytic converter, and its main purpose is to what? Shield heat!
TOM: The heat shield has two parts. It has an upper part and a lower part. One consequence of losing the upper heat shield is that the Swiss cheese sandwich you put between the seats on the way to work will be a grilled cheese sandwich by the time you got there. In other words, the floor of the car could get very hot.
RAY: The consequences of losing the bottom heat shield aqre potentially more serious--unless, of course, you REALLY hate grilled cheese. If you lose the bottom part of your heat shield, when you park your car, the heat fro the catalytic converter could actually ignite something and start a fire.
TOM: Now, if you live in the country, and park the car over tall grass or dried leaves, the danger of starting a fire is obviously much greater. But it could happen in the city too, if you park over a pile of leaves or even something like trash. So we think the heat shield is something you definitely SHOULD replace.
RAY: And it's something that CAN be replaced. I'm sure there's an aftermarket heat shield that will fit your car, Suzanne. If your mechanic doesn't want to go through the trouble of getting you one from a local auto-parts supplier, I'm sure you can find another mechanic who will.
Dear Tom and RAy:
I've seen plenty of your articles on downshifting. how about a question on upshifting? Is ther any harm to anything if, when you reach the correct speed, you shift from Third to Fifth, skipping Fourth gear?--John
TOM: That's an extremely interesting question, John. And I'll bet that most people don't know the answer to it.
RAY: The truth is, on a flat road, most cars have more gears than they need. The time you really need all the gears is when you're going up hills.
TOM: Think about riding a 10-speed bike. If you're strong, and you're on level ground, you can start in Third, and then shift to Eighth! But on the hills, finding the right gear becomes much more important.
RAY: So you won't do any long-term damage to thwe transmission by skipping gears. But you DO have to be careful about the engine. If you go into a higher gear too soon, you'll be "lugging" the engine, and that's not good for it.
TOM: But the engine hs ways of telling you when it's being lugged. It starts to ping, and when it's really being lugged, it starts to buck and shudder. If it could , it would open the hood, come around the side of the car , and give you a dope slap...but it can't.
RAY: So as long as you're not causing pinging or bucking, you can skip any gears you like. In fact, just for vaariety, you might try using First, Third and Fifth on Mondays, Wednesdays and Fridays, and Second and Fourth and Reverse on Tuesdays, Thursdays and Saturdays.