How to identify a faulty hydraulic valve lifter

Diagnostics of the component requires a stethoscope. Diagnostics is performed on running engine. Resonator of the device should be brought into proximity with each hydraulic valve lifter, one by one. Strong knocking sound from the component indicates its failure. The second method is pressing the components with a finger, one by one, with the engine stopped. Serviceable hydraulic valve lifters cannot be pressed in. To obtain more precise data, seek the help of specialists at a service station.

You may notice that the hydraulic valve lifter may need diagnostics by the following symptoms:

• extraneous sounds during engine operation;
• reduced engine power;
• accelerated wear of valves;
• increased fuel consumption.

The reasons of hydraulic valve lifters failure

The main reason of car hydraulic valve lifters premature failure is the use of poor quality oil. If its viscosity is below the required value, engine components are lubricated insufficiently, and are exposed to increased abrasion. The products of their wear are the cause of oil channels clogging, sticking of the plunger and barrel assembly or of the check valve. Similar consequences are caused by failure to replace oil according to the prescribed schedule, or change of its original properties due to engine overheating.

Incorrect operation of hydraulic valve lifters may be due to the lack of oil in the engine lubrication system, in which case the pressure inside the components does not reach the required values.

Another reason of components fault is their natural wear. Over time, it results in an increased clearance in the plunger and barrel assembly, which makes the hydraulic valve lifters be activated with delay. Special additives help to maintain the working performance of the components. The ingredients they contain get deposited on the surface of worn-out components, restoring their initial size, and contribute to forming a strong oil film that is thicker than usual. Due to this, high leak-proof properties of the unit are maintained throughout the entire service life of the component.

Repairing hydraulic valve lifters

Repair of the component is a temporary measure; it is only possible if the component is divisible. Usually it consists in cleaning the elements of carbon deposit. It is recommended to rinse all hydraulic valve lifters at once. For this purpose, remove them from the engine, put them in a container with solvent, which can be kerosene, gasoline or acetone, and leave them there for a while. After the carbon deposit has dissolved, the elements are to be cleaned with thick cloth. Before installation, cleaned hydraulic valve lifters are to be filled with oil, and checked for pressing in. If the components failure cannot be removed this way, the components are to be replaced.

Replacing hydraulic valve lifters

The process of replacing hydraulic valve lifters is quite complex, and requires special equipment. In many cases, to access the components, one will have to remove the air filter, the timing belt, to disconnect the electrical wires and radiator hoses. One should also remove the cylinder head cover and the camshaft. Then rocker arm shafts are removed, and hydraulic valve lifters are extracted from their seats. If you do not want to spend too much time for repair, ask specialists for help.