As Oil Pressure Rises, Noise Dims

May 07, 1989|By Phil Arendt.

Q-My 1988 Buick Regal with 3,000 miles on it has developed a clattering noise. It sounds like a piston is slapping when I first start the car in the morning. After a few seconds, the clattering stops. What can it be? A.L., Palos Hills

A-It is not uncommon to hear certain noises when starting an engine. While the engine is off, oil drains back into the oil pan. If the engine is idle for a long period, such as overnight, very little oil is left in important areas such as the crankshaft and pistons. Valve lifters, which depend on oil pressure to operate, also are lacking lubrication.

Once the engine starts, noises can be heard until the oil pump builds up pressure and delivers oil to the engine. To determine whether the problem is worth a mechanic`s attention, your best bet is to take the car to a Buick dealer. If the engine needs work, the warranty should cover it.

Q-After 106,000 miles, my 1982 Ford Bronco has developed an excessive oil leak. It always gave me great service until this problem cropped up. My friend, a mechanic, says the leak is coming from an area above the timing chain cover, near the intake manifold gasket. He says he`s surprised the leak didn`t show up sooner. Because it would cost about $200 to have it fixed, he insists I`m better off to live with the problem, keeping an eye on the oil level and topping off as necessary. Do you agree? R.M., Westchester

A-It depends on how severe the leak is, and how long you intend to keep the vehicle. Before making a decision, clean the engine thoroughly and watch for the oil leak. If it`s not a gusher, it is less expensive to add oil, unless you intend to keep the truck for another 100,000 miles. A piece of cardboard or plywood under the engine will keep the garage floor from gathering too many oil stains.

Q-I have a brake problem with my 1978 Dodge. It all began two years ago, when a garage did a brake job. Ever since then, the brakes become spongy after driving in traffic. I have taken the car back to the mechanic, who inspected the brake system but found nothing wrong. Then I went to another mechanic, who replaced the master cylinder. Still a third mechanic suggested replacing the wheel cylinders and overhauling the pistons in the disc brakes. What should I do? R.H., Mundelein

A-It sounds as if the system is suffering from a malady called ``dreaded brake fluid vapor lock`` by mechanics. It is no laughing matter. The symptoms show up once the brake system gets warm. Before tearing into the cylinders and calipers, I suggest flushing the brake fluid from the entire system, replenishing it with a fresh supply. Old brake fluid boils at lower temperatures than fresh fluid. Whatever you do, get this problem fixed. Don`t put it off.

Q-When driving over bumps, even small ones, my 1986 Chrysler LeBaron suspension bottoms out. The dealer has replaced the front struts and springs, but the car still hits bottom. I`ve complained to the regional service office and dealer service manager, but they are at a loss to find a reason the car won`t respond the repairs. Can you help? D.G., Downers Grove

A-It`s not uncommon for the average car to hit bottom once in a while. Unless you regularly carry a ton of bricks, though, your car should have responded to the repairs. One solution is to install heavy-duty springs. As long as you are upgrading the front end, you could consider installing new rear springs, as well.

Q-The day after we bought a used 1985 Ford Country Squire station wagon, I noticed transmission trouble. Here`s what happens: When the transmission is cold, the car won`t move after getting to a stop sign-unless I put it in reverse. If I do that, and wait a moment, then shift into drive, the car moves away without a hitch. I took the car to a transmission shop, where the technician was bumfuzzled. He has no idea what causes this mysterious problem. Do you? R.E., Blue Island

A-Believe it or not, I get letters all the time from people with similar, strange transmission problems. Yours was the third letter in one day. The most likely cause of this problem is the shift valve. If so, fluid pressure is not being applied to the forward clutch, which prevents the car from moving. Ask your technician to inspect the shift valve and he may isolate the problem. Not to sound preachy, but it it likely that the transmission problem was known to the previous owner, which is how the vehicle ended up on a used car lot. When buying a used car, it is smart to have a good mechanic give it a test drive before laying out money.

Q-The protective boots that cover the constant velocity joints on my 1981 Buick have been replaced seven times. Each time, the mechanic says the car must have hit an object in the road. Do you think that`s possible? H.W.K., Westchester

A-Nothing is impossible, but there is another likely problem: The boots may have been installed improperly. If the same repair shop has replaced them that many times, I suggest you try another facility for service effort No. 8. ----------

Phil Arendt is manager of automotive information for the AAA-Chicago Motor Club. Readers may send technical questions about cars and trucks to him at Dr. Gizmo, AAA-Chicago Motor Club, 999 E. Touhy Ave., Des Plaines, Ill. 60018.