Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 28 YEAR 2000

by Bob Hagin

Q. Recently I was driving my 1994 Toyota Camry V6 on the highway and as I passed a large truck, I heard a ticking noise ricocheting off of it. The noise was coming from my car but I kept going. A mile or so later my engine literally blew up. Since I have a Toyota extended warrenty, I took it to a dealership where the engine was dismantled. A factory service representative inspected it and said that the damage was caused by a lack of oil reaching the bearings. He also said that the oil pickup screen was 70-percent restricted by engine sludge. I've always maintained the car as per the service schedule but several weeks ago I had an independent garage clean out the engine with an engine flush. It had approximately 90,000 miles on it. A.R. Las Vegas, NV

A. I only do an engine flush when I'm going to take apart an engine for a rebuild or an overhaul. It was common practice in the days before the positive crankcase ventilation (PCV) system which pulls most of the oil contaminants out of the pan and into the intake manifold while they're still in a gaseous state. From there, the contaminants are pulled into the cylinders and burned. But it doesn't get it all and despite the detergents that are blended into modern engine oils, what's left eventually leaves a soft residue on the internal parts. This stuff is pretty well glued to the interior parts and stays there without doing damage to an engine that has had it's oil and filter changed regularly (3000 miles) since new. But when a high-mileage engine like yours gets flushed, the residue is washed loose and pulled into the oil pump. If it's too thick or there's too much of it, it can plug the screen on the oil pump, starve the engine for oil and it scatters.

Q. I have a 1986 Dodge D250 truck. My air conditioner needs work, leak detection and recharging. The current cost of R-12 refrigerant is unofficially $25 per pound (plus or minus) which is pretty high for someone on a fixed income. I have seen advertisements for conversion kits by Interdynamics and Castrol and I would like to know if there are any drawbacks to using these kits to convert from R-12 to R-134A. F.B. North Highlands, CA

A. My son Andy has done several of those conversion as have several other shops in our area. None of them have had problems with the conversions as long as all of the old refrigerant is purged and the conversion is done carefully. The conversion is practical if you plan to keep your Dodge long enough to see it through another couple of a/c services. R-12 isn't even legal in some areas due to its effect on the environment. It's so costly it's commonly recycled from wrecked cars.

Q. I am a senior and unfortunately my granddaughter had a sever accident which stove in the right door of my 1979 Plymouth Scamp a few years back. Currently I have no vehicle at all to take me shopping and to church so I must rely on my fellow seniors. When my husband was alive, he took care of our cars but I didn't pay much attention. Can you recommend a serviceable automobile for me? I would prefer a four-door sedan with six cylinders although most makes now use four cylinders. I have a hip problem and must use my left foot on the brake pedal. M.W. Virginia Beach, VA

A. The April issue of Consumer Reports is all about autos, new and used, and it does honest evaluations. The other members of your group are good information sources, too. Whatever car you try, do an extended road test and if the seller won't allow it, look somewhere else. I get many letters from readers who say that their new cars ride too hard or are uncomfortable - but then it's too late. And take someone with you when you shop. If you buy new, the attitude at the dealership and reliability of the shop are as important as the brand you buy.