ZEST BOLT Service Manual

Revotron 1.2T 14 4. Engine Noise Condition Possible Cause Remedy Engine 'pings' or 'knocks' while accelerating or travelling uphill. Improper grade of fuel • Fill fuel tank with a minimum BSIV Fuel Spark plugs excessively worn or gapped improperly. • Inspect spark plugs. Replace if worn. Incorrect valve/ignition timing • Check timing system components and repair or replace as necessary. Excessively worn camshaft • Inspect camshaft lobes and run-out for excessive wear. Replace as necessary Malfunctioning fuel pressure regulator • Check fuel pressure regulator and return line. Repair or replace as necessary. 'Squeal' or 'chirping' while engine is running. Worn, oil-fouled, or improperly adjusted engine accessory belt. • Check engine accessory belt condition and tension. Adjust or replace. Belt tensioner not properly tightened or defective • Inspect the belt tensioners. Tighten or replace as necessary. 'Clunking' or 'rapping' noise from bottom end of engine Defective piston wrist pin, rod, or main bearings • If noise occurs after taking foot off accelerator pedal, inspect piston wrist pins. • If noise is constant inspect rod bearings and main bearings for proper clearance and condition • Replace bearings as necessary. 'Tapping' or 'ticking' noise from the top end of the engine Improper valve tappet clearances • Check and adjust as necessary. Fuel injectors worn excessively • Fuel injectors will make some ticking noise. Replace fuel injectors if not putting out enough fuel to cylinders. Excessively worn camshaft • Inspect camshaft. lobes and runout for excessive wear. Replace as necessary. Valve springs, tappets, or rocker arms worn • Inspect valve train components; replace as necessary. 5. Engine Smokes Condition Possible Cause Remedy Engine emits white smoke from tailpipe Obstructed air filter or air Inlet • Clean or replace air filter or Inlet. Head gasket leaking coolant into combustion chamber • Inspect engine oil for coolant and perform engine compression test. Engine cylinder head or block cracked • Inspect engine oil for coolant and perform engine compression test. Engine oil or other substance on exhaust manifold • Inspect exhaust manifold for foreign material. Improper grade or contaminated fuel • Rush fuel system with fresh, clean, fuel of the correct type. Replace fuel filter.