Noisy Belts Cry for Attention
Question: I own a 1983 Volvo. At 45,000 miles, all the belts were replaced on the engine. After just 12,000 miles, the belts to the power steering pump and the air conditioning compressor became quite noisy. One mechanic claims I need new belts. A dealership mechanic said the pulley had become glazed and needed to be sanded, which did not seem to help. Treating the belts with a belt dressing helps, but only temporarily. Can you suggest a remedy?
--G.K.
Answer: Drive belts are being called upon to perform much greater work than ever before. Belts themselves have dramatically improved, increasing the amount of power transmission and allowing greater bending around small diameter pulleys.
Over time, belts degrade from heat and normal wear. Atmospheric pollution attacks the rubber and other synthetic materials in the belts. So, a periodic replacement is necessary, although many dealerships try to carry this advice to the absurd and push unnecessary annual belt replacements.
A squealing belt in many cases means the belt is slipping or creeping when going around a pulley. A properly designed belt and pulley system will creep less than 1%.
Several factors could be causing your noise. Perhaps the belts were not properly tensioned. The belts should have been installed using a tool that measures belt deflection.
If the belts are too tight, they can cause excessive wear on the ball bearings inside the power steering pump or the air conditioning compressor. If the belts are too loose, they can slip.
Another possibility is that the belts were the wrong type for your car. Perhaps the garage installed a newer type of belt, either a grooved or ribbed belt, while your Volvo required a standard V-belt.
Finally, perhaps the basic design of the belt drive in your Volvo fosters rapid wear and squeal. Some car engines can easily go more than 100,000 miles between belt changes and other require new belts four times more often.
Q: I own a 1989 Cadillac Seville. During a recent hot spell, I began monitoring the digital temperature gauges on my dashboard. The owner’s manual states that my engine has a 195-degree thermostat, yet on hot days the temperature would reach 226 degrees and on cool nights drop to 175 degrees. A dealer told me this is normal, but I am still not comfortable. Can you shed any light on this?--M.D.
A: The thermostat in your engine regulates the flow of coolant from the radiator to the engine, but doesn’t precisely control the temperature like a home thermostat.
In severe driving conditions, the coolant temperature will rise above normal, but the engine is not necessarily overheating. It is simply a case of the cooling system not being able to shed the heat it does when outside air is much cooler.
The the boiling point of the engine coolant is about 264 degrees. On most GM cooling systems, the dashboard engine warning light will alert the driver to overheating when the coolant reaches about 245 to 250 degrees, providing a 15- to 20-degree margin before it boils over.
If on the very hottest day of the year your coolant temperature is 226 degrees, you were still toward the upper end of a normal range--especially if you were using the air conditioning and the car was idling in heavy traffic.
Vartabedian will attempt to respond in this column to automotive questions of general interest. Write to Your Wheels, Times Mirror Square, Los Angeles 90053.
