There is an ordinary Santana, travel 280,000 km, due to the engine burn oil and valve ring and other needs of the engine overhaul.
    Overhaul process, all the procedures are strictly in accordance with operating procedures, equipment, according to manufacturers when the technical requirements. After the car, the engine work properly, but the operation will soon appear "despair, despair" crisp sound. So the use of the traditional "off fire" method for abnormal sound to determine, abnormal sound is still more obvious, but with the engine speed increases, the gas is reduced, due to the sound in the upper part of the engine, the sound is more crisp, But has been replaced by hydraulic valve tappet, valve, etc., therefore, decided to open the valve compartment cover check. If the hydraulic tappet wears seriously, the valve lifter in the movement can not be flexible rotation, will increase the cam up the tappet of the lateral force, so that the tappet in the movement around the pendulum, affecting the normal work of the tappet. Check the valve tappet and tappet hole with the gap, the normal gap is 0.12mm, after checking the tappet to mention a little plug, there is a sense of gap, therefore, replace the hydraulic tappet a group (8) assembled, Sound still.
    And judged to be due to low oil pressure, but the car after the oil table (for the red light instructions) work properly, because this car is no oil pressure gauge. So in the oil sensor (a high pressure sensor, a low pressure sensor) the middle of the connection 212 jeep with oil sensor test, oil pressure of 0.4MPa, by the Santana special repair station to check the data for the normal range.
    Once again replace the new hydraulic tappet, camshaft after the fault is still the case.
    With the stopper into each two-cylinder test, the sound was significantly reduced to determine the bearing due to excessive, replace the bearing (the market did not sell the original pad cover, after processing). If the gap is too small, likely to cause poor lubrication, journal ablation, so that the camshaft in a tight state of operation, accelerated wear. If the gap is too large, it is difficult to form an oil film is bound to cause friction ablation and wear. Ordinary Santana sedan no bearing, repair more difficult, so the camshaft hole on both sides and the pad cover the processing of a wide 0.2mm, deep 0.15mm oil channel, the effect is quite good, this car after the car, the sound normal, good lubrication effect. Combined with the ratio, if there are similar problems please learn from.