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ENGINE 273 MPFI 87 ENGINE PRELIMINARY INSPECTIONOF ENGINE Before proceeding to carry out actual overhauling of engine it is desirable to have a preliminary inspection of engine to ascertain whether an engine overhaul is necessary and to what extent. Most common reasons for which engine is overhauled are: 1. Loss of power 2. Excessive engine oil consumption 3. Extremely low engine oil pressure 4. Mechanical failures To know exact reason and general condition of engine, proceed as follows: 1. Loss Of Power: Loss of engine power occurs due to one or more of following reasons: • Defective Ignition system • Defective Fuel system • Clogged air cleaner/choked catalytic converter or exhaust silencer • Clutch slippage • Brake binding • Loss of engine compression a. Ignition System Check ignition coil. If found faulty, replace it. b. Fuel System Check condition of fuel filter. If found blocked, replace fuel filter. c. Clogged air cleaner/choked catalytic converter exhaust silencer Check and If found choked, clean or replace. d. Clutch Slippage Clutch slipping can be confirmed by any of the following two methods: Drive the car in 1st or 2nd gear at maximum speed corresponding to that gear. With accelerator pedal fully pressed, apply brake gradually with left foot. If the engine stalls, it means that clutch does not slip. OR Drive the car with weight equal to GVW in 3 rd gear on level ground and let the speed drop down to approximately 15 km/h or 10 mph. Now press accelerator pedal fully. With slipping clutch, the car speed will not pick up and also clutch burning smell will be noticed. If this does not occur and car picks up speed, it indicates that clutch does not slip. e. Brake Binding During driving apply brake number of times and then shift the gear to neutral position Check brake drums for overheating and if necessary jack up the car and check the wheels for free rotation. f. Loss of Engine Compression Pressure If loss of power is not on account of defective fuel system, lack of air, choked exhaust silencer, clutch sl ipping and brake binding. Check engine compression. (Refer on VehicleRepair Procedure to check engine compression Procedure) 2. Excessive Engine Oil Consumption: Maximum limit for Oil Consumption = 100 cc/ 1000 km = 100 cc/ 625 miles High engine oil consumption may also lead to overhauling of the engine but before proceeding to overhauling, check following points : 1. Make sure that there is absolutely no external oil leak (i.e. from the camshaft oil seal, crankshaft oil seal, oil sump gasket, oil pump gasket, cylinder head cover gasket etc.) 2. If no external leakage is found, determine the exact engine oil consumption, as per following procedure. Determining Exact Oil Consumption CAUTION Do not make a rough estimate of engine oil consumption by noting the kilometers covered by the car at any random stage and finding oil consumed from the topped up position taking into consideration dipstick level and oil sump capacity. Procedure: 1. To confirm that engine oil consumption is higher, place the car on a level ground. 2. Top up oil sump to its capacity of 2.2 liters. 3. Warm up the engine so that oil temperature is 75 °C to 80 °C. 4. Take a clean vessel, place it below the drain plug of oil sump. 5. Drain the hot oil into the clean vessel. Drain it fully. 6. Screw in oil sump drain plug and tighten it. 7. Weigh the vessel along with oil let this weight be ‘w1’, gms.