Of the many car repair jobs that one needs to undertake in a lifetime, replacements are the most tedious. Especially, if the car part is something deeply embedded in the mechanism, then the replacement procedure is not so easy. One such part is the tensioner.
The car's functioning is made possible by a well-timed engine cycle. Its periodicity is maintained by the self-coordinating mechanism of the timing belt. It forms the physical connection between the crankshaft and camshaft of the engine. It controls the opening timing of the exhaust valves of an engine and other connected engine parts.
As its name suggests, the tensioner's prime objective is to maintain tension on the timing belt and ensure that it remains aligned properly. It consists of a pulley arrangement that aligns the belt, while maintaining the right amount of tension. Maintaining it is immensely important, as it determines how smoothly the belt works.
When a tensioner fails or breaks down, the belt is no longer taut enough to synchronize the timing between the crankshaft and camshaft, leading to major engine problems. That's why, it is important that its replacement be taken seriously. Car manufacturers recommend a belt replacement after an average of 60,000 miles of running. The tensioner is generally replaced along with the belt, after the same time period.
The designing of every car differs slightly and therefore, it is not possible for me to provide an exact procedure for tensioner belt replacement. What I present here is an outline at best. For a detailed procedure, refer to the appropriate Hayne's manual for your car model. Have your car repair wrenches, sockets, and screwdrivers in readiness. Have a new tensioner ready, which should be an exact replacement of the old one.
Before you do anything, remove the battery's negative terminal as a precautionary measure. Then what you need to do is remove the distributor cap and set the camshaft to the 'top dead center' (TDC) position. For details regarding how this is done, refer to your car manual as it is a complex procedure.
The next part of the job is to systematically remove every car part that blocks your access to the belt assembly. This may include a removal of the power steering pump, air intake mechanism, and water pump. Once you remove all these parts, you will gain access to the belt cover that will have to be removed. Then you will have access to the belt assembly. Locate the tensioner and its mounting bolts. Slowly loosen them, which will loosen the pulley. Carefully remove the belt and set it apart. Check the pulley for worn bearings and damage signs.
If you find the bearings to have been worn out and find cracks in the pulley, replace it. Remove the mounting bolts entirely to remove the old tensioner. Then you can proceed with replacing it entirely with a new one. Once you do that, you can tighten the new one back in place and put the timing belt back in place. The last part is to replace the belt cover and all the car parts that you removed, back in their original positions. I would personally suggest that you get the job done from a professional car mechanic, unless you are adept at such tasks.