Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 21

by Bob Hagin

Q. I bought my 1997 Toyota Avalon new in May of that year. The dealer- recommended maintenance schedule called for oil and filter changes every 3750 miles, which I have followed and intend to continue following. When I visited the dealer recently for my 22,500 mile oil and filter change, the service writer told me that I was overdue for an engine oil flush. It seems that they have now changed their recommended service interval to 5000 miles and an engine oil flush every 12,000 miles or once a year. They are using an aftermarket flushing system and not one that is put out by Toyota. Do you feel that this oil flush is really worth the additional cost with the 3750-mile interval or is it mostly a dealer promotion? All of my driving is in rather ideal driving conditions. J.K. Virginia Beach, VA

A. I've never been an advocate of periodic engine flushes but I'm told by mechanics who use these systems that if an owner has the job done on a regular basis, the engine will never have any sludge or build-up no matter how long the vehicle is in service. Dealer-recommended oil and filter change intervals are purely arbitrary and are usually about half the miles recommended by the factory, but it gets the car in for a look-see and are good income producers for a shop. I'm told that the only drawback to engine flushing (besides the expense), is that if it's done on a high-mileage engine, it will most often clean the inside of the engine so completely that the sludge that gets shaken off can plug up the oil pickup screen. In my wrench-bending days, I used a 50/50 mixture of cleaning solvent and motor oil to flush a running engine before I pulled it down for an overhaul or a rebuild.

Q. We have a 1994 Toyota Corolla that we bought second hand and it now has about 60,000 miles on it. Lately it has begun to make an unusual noise when we initially take off from a stop or when we accelerate and then decelerate rapidly. The noise seems to be coming from the rear end and the longer we drive it the worse it gets. We've taken it into our usual shop (not a Toyota dealership) but the mechanic doesn't seem to be able to pin-point the problem while the car is on the lift. Is the noise something that will lead to more problems as the car gets older and we put more miles on it? T.K. Seattle, WA

A. Usually those kinds of noises are caused by a rubber-like bushing that has worn to the point where it's lost its compression and is moving around. Volvo had the same type of problem in several of its cars over the years. The factory says that the problem is probably in the rear stabilizer bar bushings and they need to be replaced with upgraded models that are stiffer. The information that I have says that the rear strut rods themselves should be pulled at the same time and that a non-petroleum grease should be applied to the outer bushing ends. Sometimes you have to hear it from the horses mouth (in this case, the factory) to get a fix on a car problem.

Q. I want to get started in the restoration hobby as a project that I can do with my son. He's just 14 years old and has expressed an interest in building a street rod after seeing a local show that exhibited these cars. I've never really been able to enter the hobby but I now have a job that isn't so demanding. We will be starting from scratch. L.M. Alamo, CA

Make sure that your son is serious about the project before you get into it or you may have to do it all yourself. Experience is a very important item, but if you have any mechanical ability, you'll probably have fun learning as you go. A major expense will be tools, but don't chintz - get good stuff. Pick an inexpensive car to start and make sure you can get parts for it. The necessary bits and pieces for a street rod are available in kit form and the running gear is easy to find, too.