Dear Car Talk:
We have a 2011 Toyota RAV4 with 34,000 miles on it, and we live in an area where the roads are salted in the winter. I have never done a wheel alignment on the car, and the original tires have worn beautifully. However, soon it will be time for a new set of tires, so I had the dealer perform a four-wheel alignment. The report came back indicating that the rear adjusters were corroded, frozen in place and could not be broken loose. To correct the problem, both rear control arms would have to be replaced, at a cost of almost $800. To be fair, the mechanic indicated that the current setting is just over the edge of the spec and that, if it were his, he would leave it alone – which I did. My questions: Is there any way that the adjusters can be freed up – heat, extended soaking with penetrating oil, etc.? Should I be going elsewhere, like to an independent shop that might be able to save or replace just the adjusters without replacing a major portion of the rear suspension? – Jim
RAY: Yes, and yes.
I also live in the great frozen swath of the country where the roads are saltier than potato chips. And our shop has one particular alignment specialist that we send our customers to. I’d say at least one out of three times, they’ll send the car back to us with a report from the technician that says “couldn’t loosen the adjusters.”
We always get them loose. And we do exactly what you suggest: We use heat, penetrating oil and, our secret ingredient, interest in fixing it.
It takes some work. We’ll gently heat it up with the acetylene torch, and as it cools down, we’ll hit it with some penetrating oil. We may have to do that three or four times. We sometimes even have to leave it overnight and work on it again in the morning.
Take the car to a shop that is willing to spend some time futzing with it. We maintain an online database of mechanics that our readers and listeners have recommended over the years. It’s called the Mechanics Files (www.mechanicsfiles.com). You can enter your ZIP code and read the reviews of shops that other people like in your area.
And if any of you reading today have a mechanic you absolutely love (I know, that’s a rarely used sentence fragment), please enter him or her in our database and let other people know about the shop.
Is this really how a car’s fan works?
Dear Car Talk:
I have a 2002 Dodge Ram Wagon. The fan blower stopped working on anything other than the “high” setting. Poking around the internet, I found what is possibly the world’s easiest car repair: Open the hood, unplug the resistor, remove two screws, wiggle out the old resistor and replace it. I did that, and it works. Life is good! Now for the problem. That resistor is enormous, replete with big coils that look like heating coils. Is that how this whole thing works – the resistor slows down the fan by diverting (and wasting) some of the power to heat? I always thought I was saving power, and improving my fuel economy, by running the fan on lower settings. But if this is how it works, the fan is always drawing maximum power no matter what setting I use. Say it ain’t so! – Dale
RAY: Well, let’s start with the good news, Dale: You fixed your car. Hooray!
The bad news is that you discovered the dirty secret of how the fan switch works.
When you set the fan on high, electricity goes straight through the fan switch and continues on to the fan motor. If you turn down the fan speed, the same amount of electricity goes to the fan switch, but the switch engages one or more of its resistors and diverts some of that electricity, turning it into heat. That heat is just electricity going to waste – unless you happen to be cooking a 40-pound pheasant under your hood. But because less electricity ultimately makes it to the fan motor (because some is diverted as heat), the motor turns more slowly.
I should add that when you cause the fan to turn more slowly, the fan motor probably will last longer. So running the fan more slowly isn’t all bad or wasteful.
But if your only goal is to avoid wasting electricity and fuel, you’d have to run your fan on high speed all the time. And install a windmill between the seats to recapture some of that power.
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