The indispensable role of the timing belt cover


Do timing belt components need protection? If you just nodded ‘yes’, you are absolutely right. That is why carmakers shield them with a special timing belt cover. This crucial component protects the synchronous belt drive from chemicals and harmful, unwanted objects that could otherwise freely enter the system. Let’s elaborate, in what follows, on what exactly the timing belt cover does. 

Engine oil, coolant and other chemicals

Car chemicals such as engine oil, coolant and fuel are obviously indispensable to keeping any vehicle running, but they can cause irreparable damage when they end up somewhere they don’t belong, such as … in the timing belt drive.

Imagine not having a timing belt cover, and imagine coolant dripping from the coolant hose. This hose is located right above the engine, so its leaks would end up ruining the belt in no time. Or imagine seal problems in the engine, causing oil to leak from the seal and damage the tensioner as well as the timing belt (which may even swell up). A lot of timing belt problems can in fact be traced back to engine oil leakage, and a timing belt cover helps mitigate these risks.


A timing belt cover keeps debris out

In addition, oil and coolant contamination can cause dirt and debris to collect on the sprockets, wearing them out – and the timing belt along with it. Misalignment problems can occur, too. Gravel or other small material gets compacted in the pulley grooves, forcing the belt to ride out, away from the pulley. This outward move destroys the tensile member and eventually even leads to belt failure. In addition, such misalignment can severely hamper timing belt drive performance, causing high belt tracking forces, uneven tooth and land wear, edge wear and excessive noise.

Foreign matter damaging the timing belt

Another reason why timing belt covers are crucial? They keep foreign matter, such as small rigid particles, from punching the timing belt, the results of which you can see in the picture below.


The ultimate way to protect the synchronous belt drive from these unwanted objects – which will not only damage the belt itself, but the engine as well – is by making sure the timing belt cover is in place and does its job. If your vehicle engine has this shield, you can rest assured that its timing belt system and engine are safe.

Problems with the timing belt cover

Most timing belt covers are made of plastic, which can crack during installation. In the event of serious damage, you’ll need to replace the old timing belt cover with a new one. Also make sure to apply the correct torque when securing the cover. Perhaps the bolts have loosened somewhat while you were working on the engine, leading to vibrations and noises in the system. In addition, the wrong fitting can cause the timing belt cover to come into contact with the timing belt during its working period, again crippling the system.

So, not only is it crucial to have a timing belt cover in place, for all the reasons just stated; the shield should also be in impeccable condition and properly installed.