Inspect, test, and replace the auxiliary oil cooler
Some engines, Especially diesel and turbocharged engines, have an oil cooler. This oil cooler may be contained in one of the radiator tanks or mounted separately near the front of the engine or ahead of the radiator support. external oil coolers should be inspected for leaks and restricted airflow passages.
The purpose of an oil cooler is to limit maximum oil temperature. if oil temperature reaches approximately 250 deg feh. (121 deg centigrade), the oil combines with oxygen in the air to form carbon and sticky varnish. this process is known as oxidation.
An oil cooler should not be installed on vehicles that do not require one. If the engine oil “overcooled,” it cannot get hot enough for unburned fuel (from blow-by) and water (from condensation) to evaporate. oil must reach a temperature of at least 215 deg feh. (102 deg cel. ) for this to occur.
Inspect, test, and adjust drive belts, tensioners, and pulleys.
Inspect the accessory drive belts for condition and tension. On conventional V-belts, the sides of the belt are the friction surfaces, so check the sides for cracks, glazing, or loose cord material. Replace a belt showing any of these conditions. if a v-belt is severely worn, it may contact the bottom of the pulleys. Replace severely worn belts. if a belt is severely worn on just one side, check pulley alignment. V-belt pulleys must be aligned within 1/16 inch (1.6 mm) per foot of belt span. If pulleys are not aligned, check for loose accessory mounting bolts, missing spacers, or bent brackets.
V-belt tension can be checked using a variety of special testers. With one type of tester, the tool is placed over the belt at the center of the belt span. Squeezing the tool handles causes the tool dial to display belt tension, usually in pounds. But belt tension can also be checked by measuring the amount of belt deflection with the ruler, use your thumb to press on the belt at the middle of a span while holding the ruler next to the belt. If belt tension is correct, the belt should deflect 1/2 inch (12.7 mm) for every foot (30.5cm) of the belt span.
A moderately loose or worn belt may cause squealing noise when the engine is accelerated. A severely worn or loose belt may cause a discharged battery, engine overheating, a lack of power steering assist. An overtightened belt may fail suddenly, or damage the alternator front bearing. An overtightened belt can also cause the upper half of the crankshaft front main bearing to wear prematurely.
When repositioning an accessory device (alternator, power steering pump, etc) to adjust belt tension, always look for the pry points provided by the manufacturer. Some devices have slots for inserting a large screwdriver or pry bar. Others have built-in square holes to accommodate a 1/2 inch breaker bar or ratchet. Never pry on a power steering pump housing to tighten the drive belt. These housings are not meant to withstand such abuse and will be damaged, possibly causing the fluid leak.
Inspect serpentine or ribbed belts looking for missing sections of ribs, severe rib-cracking, or a damaged belt backside. These conditions call for immediate belt replacement.
Serpentine or V-ribbed belts must also be properly tensioned, but these belts are usually fitted with automatic tensioners. The tensioner automatically adjusts belt tension as the V-ribbed belt stretches. These tensioners often have built-in wear indicator scales. As long as an arrow on the tensioner is located between two lines, the belt is not excessively stretched. When the arrow moves outside the lines, the belt must be replaced.