Repair 7

The Signs of a Wiped Cam Shaft

A camshaft controls the timing of valves on an automobile engine. Lobes on a camshaft, called cams, push on the valves to open the valves. Springs on the valves close the valves. Camshafts ride on thin films of oil on camshaft bearings. A camshaft bearing goes bad, or is "wiped," when oil fails to get to the camshaft bearing. Your vehicle engine will not operate if a camshaft bearing gets wiped. The engine would seize and shut down. Regular maintenance on your vehicle, such as regularly checking the oil, prevents a camshaft from failing.

Popping Noises

A popping noise develops in the engine as a camshaft begins to fail. As the camshaft begins to fail, the timing starts to go bad, which causes the engine to develop a popping noise. This popping or backfire could indicate bad valves or valve springs, or it could be that the camshaft is failing. Mechanic John Hix says that with any engine he can hear whether the engine is not running right. The timing will lead to louder popping noises as the camshaft gets worse.

Poor Gas Mileage

Poor gas mileage will manifest itself as your car loses power and burns more gas. You will find the car burning more gas to get from point A to point B as the camshaft goes bad.

Loss of Performance

The loss of engine performance emerges as the timing deteriorates. The engine power will go way down and your engine timing will be way off. When climbing hills or trying to pass, you will notice the car will have no accelerating power. As soon as this sign manifests itself, you should have the vehicle checked by a mechanic.

Metal in the Oil

A check of the engine oil might reveal flakes. Prior to the shaft wiping, metal parts will come off the lobes of the camshaft. These naturally wear from use. Excessive wear means they need replacement. Metal flakes indicate that metal in the camshaft has contacted the metal of the bearing. The bearing metal is made from a softer metal, hence the term "wiped bearing." The metal from the shaft literally wipes the softer metal from the bearing. These metal fragments will then end up in the lube oil system; when you drain the oil you will notice metal flakes floating in the oil.