Valve cover bolts are a very important part of an engine's valve cover assembly. Responsible for stabilizing and securing a valve cover to the engine head, valve cover bolts need to be installed correctly in order to maximize bolt fixation and valve cover stability. An incorrectly-installed valve cover bolt can cause a variety of problems.
In order for valve covers to function properly, they have to be installed properly, which includes, among other things, the proper insertion, and torquing, of the valve cover bolts. Valve cover bolts ensure a smooth, even fit of the valve covers on top of the engine heads. If a valve cover bolt is installed incorrectly, it can cause an abnormal seal to develop between the valve cover and the engine head, an abnormal seal that can cause oil leakage and valve cover gasket damage.
One of the more common results of an incorrectly installed valve cover bolt is damage to the bolt threads. Generally, valve cover bolts are small, threaded, and somewhat pliable light-duty bolts that are easily damaged if they are installed incorrectly or if too much torque is used to secure them to the valve cover. Strippage of a valve cover bolt, which is what happens when the small ridges lining the sides of the bolt are stripped away, normally happens when a valve cover bolt is not only installed incorrectly but tightened significantly while in its incorrect position.
A valve cover bolt can break and/or crack if it is installed incorrectly on a valve cover. If the bolt is installed in a crooked and/or excessively angled position, significant and abnormal stress loading of the bolt can develop, especially during tightening of the bolt, which can cause the bolt to break. This type of breakage can also occur when an incorrectly installed valve cover bolt is removed or loosened. Often, excessive pressure or force is required to remove a valve cover bolt that has been incorrectly installed; if too much force is applied, the bolt can break and/or snap.
Valve covers are normally made up of lightweight aluminum and/or metal that can be damaged by valve cover bolts that have been installed incorrectly. Although valve cover bolts only contact a very small portion of the surface area of valve covers, they bolt directly to the outer valve cover edges, the areas that help to ensure a tight, snug fit of the valve covers to the engine head. An incorrectly installed valve cover bolt can cause warpage to the area of the valve cover secured by the valve cover bolt. Warpage to this area of the valve cover can compromise the sealing ability of the valve cover itself, a situation that can cause an oil leak.
When a valve cover bolt is installed and tightened on a valve cover, the bottom portion of the bolt anchors directly into the engine head. This anchoring of the valve cover bolt into the engine head keeps the valve cover firmly in place. If a valve cover bolt is installed incorrectly, warpage to the engine head screw holes can result, which can prevent the valve cover from being installed securely. Also, strippage of the grooves lining the engine head screw holes can result from a valve cover bolt installed incorrectly, a situation that can prevent the valve cover from being anchored securely to the engine head. Both situations can result in a poor fitting valve cover that develops oil leaks.
