It’s always a bit scary when an unfamiliar noise starts coming from somewhere under the hood. Many of us don’t know enough about complex engine systems to know if it’s something to worry about or not. The following are some of the most common reasons for engine noises that require action:
Valve Train Noise
Valve and hydraulic lifter noise is a clicking sound that usually quiets down when you raise the engine’s RPM’s. Lifter noises can be caused by worn or sticking hydraulic lifters. Sticking lifters are caused by a varnish buildup on the lifter surfaces. The problem with a sticking lifter may be solved by adding a detergent additive to the oil. If this doesn’t do away with the noise, the job will need to be done by a trained auto repair technician at Stryker Brothers Automotive, a reputable car repair shop near Lake Stevens, WA.
Timing Chain Noise
The timing chain connects the crankshaft to the camshaft to ensure the valves open at the proper time. The slack in these chains is kept tight by hydraulic tensioners. When the chain guides are too worn for the hydraulic tensioner to take up the slack, noise is caused by the loosened timing chains.
Connecting Rod Noise
A connecting rod noise is caused by excessive clearance between the crankshaft and the connecting rod bearing surface. The noise is a knock that is heard toward the bottom of the engine. These problems require swift attention because the continued running of the engine in this condition damages the crankshaft.
When an engine is running and making a whining noise, it usually indicates a bearing that is on the verge of failure. However, some of the items under the hood that can make a whining sound include the water pump, AC clutch bearing, fan-belt idler pulleys, alternator, and the power steering pump. Whining from the power steering pump gets louder when turning the steering wheel from side to side and the usual cause is low power steering fluid.