Rebuilt engine a perfect option, Have the rest of the car checked out before doing more

DEAR TOM AND RAY: Would it be crazy to put a rebuilt engine in a12-year-old car? I use my old Mazda wagon as a dogmobile for my dog-walking business. I've been looking at new cars, but I don't think Icould stand it if the dogs scratched up the inside of my new carlike they've done to this old one. Will a rebuilt engine give myMazda a new lease on life?

Sally

RAY: Absolutely. You're the perfect candidate for a rebuiltengine, Sally. In fact, the American Association of EngineRebuilders will probably want you to star in their next TVcommercial.

TOM: Here's your situation, Sally: You have a car which - asidefrom a worn-out engine - serves you perfectly well. So why spend aton of money on a new, or newer, car that you don't even reallywant? Just throw an engine in it.

RAY: The one thing that you absolutely have to do, though, ishave the rest of the old Mazda thoroughly checked out before you putthe engine in. Have a mechanic you trust go over the old beast fromheadlight to tailpipe, as if you were going to buy it as a used car.Find out everything that's wrong with it and factor that into yourcalculations.

TOM: So, for instance, if it needs new shocks, that's no bigdeal. You put in an engine and shocks, and you're happily toting thedoggies around again.

RAY: But if you find out that you also need a new transmissionand your frame is rusted, then you might want to reconsider.

TOM: I've got it. If it's not worth putting an engine in it, shecould just rig up a harness and let the dogs pull HER. How manyPekingese does it take to pull a Mazda?

RAY: I'll have to look it up. But if the car checks outreasonably well, then by all means, toss in a new engine and keepdriving, Sally.

Dear Tom and Ray:

I have a 1987 Olds Cutlass Ciera in very good condition with67,000 miles. The brakes stop the car promptly, smoothly and withoutpulsation. The pads have been replaced once, and the rotors havenever been machined. When I took it to a brake and muffler shop,they showed me that one side of my rotors was rusting. To me, itlooked like little sand holes. I suggested machining that side, butthe mechanic told me both sides would have to be machined, and thatwould make the rotors too thin to use. He wouldn't replace the padsunless I replaced the rotors. Can't I just have just one sidemachined?

Abe

TOM: That's a good question, Abe, but the answer is no, youreally can't machine just one side.

RAY: Theoretically you could. But in reality, the lathes are setup so that the rotors get pressed by blades from both sidessimultaneously. If you apply pressure to only one side, the rotorwill "give" whenever there's a bump or defect, and you won't reallysmooth out the surface, which is the whole point of machining. Inother words, you'll get a lousy job.

TOM: How does he know? He's done LOTS of lousy jobs on rotors!

RAY: At 67,000 miles, I suspect your mechanic is right. Therotors probably are worn down to the point where machining themcorrectly would take them below specification (make them too thin).

TOM: Moreover, if only one side of the rotor is rusted, I'd beconcerned that a caliper slide is stuck. Because when a caliper isworking properly, the pads should be applying pressure to, andscraping rust off of, both sides simultaneously.

RAY: So this is not the time or place to be a cheapskate, Abe.You really want the calipers working properly and the pads androtors in perfect, point-to-point contact so you get optimalbraking. After all, those doughnut shops can come up on you awfullyfast!

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