Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 26 YEAR 2000

by Bob Hagin

Q. I purchased a demonstrator 2000 Chevrolet Impala with 6000 miles. It now has 9000. It rides very rough. We hear every bump and feel them too. I have taken it to three different dealers with no satisfaction. The first one was where we bought it and they tightened one bolt on the sway bar. It didn't wobble as much but it just almost bottoms out. Going slow is even worse. I was told "...that's the way the car is supposed to ride, it's a luxury car. No one else has complained. We can do nothing more," by the customer service person. It's a beautiful car otherwise and I've never complained about a new car before. It is not the LS model and it has the 3800 engine. L.J. Shorewood, IL

A. The Chevrolet Impala is a nice car but it would be stretching it to call it a "luxury" model. There's a simple test to see if all new Impalas perform and ride like yours. Ask your selling dealer to let you take his latest demonstrator for a short spin over the same kind of terrain you drive your own car on. If the same model rides, drives and performs like your car, you bought the wrong make and/or model vehicle in which case you're pretty well stuck with it. On the other hand, if an identical car (same tires, accessories, etc.) rides differently, there's something wrong with the chassis or suspension and the factory field representative should be called in to examine it on a lift.

Q. I bought my '86 Chevrolet Celebrity station wagon new. It has the 2.5-liter fuel injected engine and a four-speed manual transmission. It's gone 74,000 miles. About two years ago a noise started happening under the hood. It sounded like slipping belts so I had my son change all the belts. When he started the engine with the belts off, the noise was still there but when he revved it up, the noise went away. Then he changed the alternator, checked the idler pulley for worn bearings, put new gaskets in the throttle body and the EGR but the whine or squeal was still there. It seems to be focused near the air cleaner. When I start the engine and it's running fast, there's no whine but as soon as it drops to a lower speed, it starts again. I get 30 mpg and burn under a quart of oil every 1000 miles. When the engine is warmed up, it run just fine and when starting in hot weather, there is no noticeable noise. J.C. Sierraville, CA

A. Obviously something is tight or possibly a vacuum circuit is open when the engine is cold and heat either closes up the opening or expands whatever is scraping. Take off the air cleaner when the engine and the weather were cold, start the engine and put one end of a three-foot piece of 3/8-inch vacuum hose in your ear and then move the other end over the suspected area as slowly as possible. The noise will travel up the hose and be loudest when the hose is on the spot. This will give you the location. At 30 miles per gallon, maybe you'd better leave it alone.

Q. I do some of the easy maintenance jobs on my 1993 Dodge Ram 50 pickup truck. I bought it new and it's given good service. I've come across a reference in the manual that says to clean or replace the PCV valve. What does the PCV valve do? is it really important? O.S. Portsmouth, VA

A. The positive crankcase ventilation valve is a simple device that allows crankcase pollutants (water, acids, etc.) to be sucked into the intake system where they're burned. It usually consists of a tube with a spring-loaded "bullet" that interrupts a hose from the manifold to the crankcase. It opens under intake vacuum and allows the fumes to be sucked in. Intake manifold backfires can't set off the fumes in the crankcase since the "bullet" only operates in one direction. It's important that the PCV valve is clean and free-acting.