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Valve Lifter Replacement


That dreaded engine knock. It can be several things, but for most people, it is a definite sign of lifters that have gone bad.

Valve lifters are the units activated by the offset lobes of the camshaft as it turns and are integral to the engine's timing. As the crankshaft turns the timing belt/chain or gears, which in turn give motion to the crankshaft(s), the lobes on those shafts push and release valve lifters, which are responsible for the opening and closing of the valves themselves.

Lifters work on impact rather than with a steady rotational or sliding motion. This means that they are more prone to wear over time, making them one of the most common mechanical repair items on a high-mileage engine. In most engines, they are accessible by removing the valve covers. Removing those valve covers, however, can mean removing a lot of other engine components first. That can make this job a time-consuming one. It is otherwise relatively simple.

In most engines, every camshaft will have a set of lifters associated with it. Usually at least two per cylinder, but often more than that.

Getting the lifters off, once access is gained, is usually a matter of removing the rocker assembly from the top of the camshaft, which often pulls the lifters out with it. Other engines may require camshaft removal, which further adds difficulty and time to the job. If you aren't familiar with timing belt/chain removal and replacement and your lifters require camshaft removal, you may need to find a professional rather than attempting to DIY this job.

It's generally a good idea to replace all of the lifters at once. So get replacements that match your engine and remove/replace them one by one until every lifter on the engine has been replaced. This reduces chances that another will fail and require replacement soon.

Be aware that it's often recommended that you soak the new lifters in engine oil for a few hours before putting them on the engine. This will permeate the hydraulics with oil to better protect them during the initial time between your starting the vehicle and the lifters getting lubricated by the engine.