Checking the serviceability of hydraulic tappets (Mercedes-Benz Sprinter 903)

The noise of hydraulic tappets is almost inaudible due to the fact that they are in constant contact with the camshaft. If noise occurs from the camshaft area, the following checks must be performed:

• let the engine run for 5 minutes at about 3000 rpm⁻¹;
• remove the cylinder head cover;
• while turning the crankshaft, stop the camshaft with the back side of the cam above the hydraulic tappet you are interested in so that the pointed working part of the cam is directed upwards;

• using a mandrel, press the hydraulic tappet down as shown in the figure 115, or move his hand;
• if the hydraulic tappet is easily pressed down or you feel play between the tappet and the back of the cam, then such a hydraulic tappet should be replaced with a new one. Hydraulic tappets are supplied with built-in hydraulic compensators. Although the compensator can be restored, we do not recommend that you undertake this work, which involves many complex measurements.