When your vehicle stops running all of the sudden, it is commonly due to a broken timing belt or timing chain. Different engine combinations utilize either a belt or chain that is connected to the cam and crankshaft and is responsible for the internal operation of a combustion engine. They are both protected from exposure by a timing cover which can be opened and accessed by a mechanic to repair damage to these components or make adjustments as needed.
The timing chain cover is responsible for keeping dirt and debris from entering the inside of the engine. Due to the fact that the timing chain and belt are housed inside the engine, the timing cover even helps to keep the timing belt or timing chain solid and secure for smooth operation. The timing cover is constructed of plastic or metal and works in conjunction with the timing cover gasket to keep oil from leaking onto the ground.
Although the timing cover is not a moving part, from time to time damage may be done to the cover or the gasket inside that will require service or replacement by an ASE certified mechanic. When the parts wear out, they tend to display certain warning signs or symptoms. Noted below are a few of the common warning indicators that a problem with the timing cover exists.
1. Oil is leaking in the center of the vehicle
The timing cover has a gasket that allows the cover to be securely attached to the engine block. Over time and due to exposure to heat, dirt, road grime, and more, the gasket can often become cracked or wear out. This will reduce the tightness of the timing cover and may result in oil escaping the engine and leaking onto the ground. A broken gasket is not the only reason why oil might be leaking from the timing cover. In some cases the timing cover may be cracked, especially if it is manufactured out of plastic. If you notice that oil is leaking from the center of the motor, near the front, it may be due to a faulty timing cover or timing cover gasket.
2. Engine runs rough
Another common signal that a problem with the timing cover exists is if the motor runs rough. When a timing cover becomes damaged and does not properly seal with the engine block, dirt and debris can enter the engine; especially in critical areas like the crankshaft or camshaft. When this happens, the engine may run rough. If the problem is not fixed soon, it may result in complete engine failure. If you notice that the engine is running rough or sounds like it is misfiring, please contact a mechanic as soon as possible to determine the cause of this symptom and if needed, replace the timing cover.
3. Knocking sound coming from the engine
When the timing cover is loose, it may cause a knocking sound to appear from near the front of the motor. If you hear this type of sound, drive the vehicle home as soon as possible. Once you arrive home, open the hood and look right behind the radiator fan. If you see a flat, metal plate that appears to be shaking, this is most likely the timing cover that is loose. The sound is due to clanking against the engine block. If this is happening, do not start the engine again. Contact a local ASE certified mechanic so they can inspect the problem and replace the timing cover if needed.
4. Check Engine Light comes on
The timing cover is designed to seal the engine and keep oil or pressure from escaping. If a pressure or vacuum situation occurs, sensors in the motor will trigger the Check Engine Light to illuminate on the dashboard. Anytime this light appears, it's advised to take it seriously, as it could signify a major problem within the engine. When the timing cover is loose – this is a major problem.
Under normal driving situations, the timing cover should never cause a problem. Typically when an engine approaches 100,000 miles of service, the timing cover gasket may begin to wear out, causing oil to drip from the engine. Since the timing cover is also near the serpentine belt, it may cause the oil to splatter and run under the entire engine. If you notice any of the above warning signs, contact a certified mechanic from YourMechanic as soon as possible.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Timing Cover and was authored by Timothy Charlet.