What Causes the Engine Idle to Sound Like a Tractor?
1 Answers
Engine shaking and sounding like a tractor is a phenomenon called "engine backfire." Engine backfire occurs when, after the piston completes its work in the cylinder, the exhaust gases from combustion should exit through the exhaust pipe. However, due to some malfunction, the exhaust valve closes, preventing the gases from escaping or not allowing enough time for them to exit. As a result, the exhaust gases are forced out through other parts such as individual cylinders in the cylinder head, the crankcase, the carburetor, or the throttle valve, commonly referred to as "backflow" or engine backfire. Here are the common causes of engine backfire: 1. Overly Lean Air-Fuel Mixture: Possible causes include faults in the fuel system or intake system: Fuel system issues are mainly due to insufficient fuel injection by the injector, which can be caused by low fuel pressure or a clogged injector. Intake system faults are primarily due to excessive air intake, which can result from a malfunctioning sensor that controls air intake or a leak in the intake manifold. 2. Ignition System Problems: Mainly insufficient ignition energy (excessive resistance in high-voltage wires; damaged ignition coil; insufficient power supply voltage) or faulty spark plugs. 3. Excessive Ignition Timing Advance: Causes include improper CKP (crankshaft position sensor) gap; loose CKP; damaged temperature sensor; engine load; or a faulty ECU. 4. Excessive Deviation from Correct Ignition Timing: Symptoms: If the engine exhibits both backfire and loud popping noises, it is often due to incorrectly connected high-voltage wires for the cylinders. If the symptoms are less severe but occur intermittently and seemingly with a pattern, it is usually caused by cracks in the distributor cap, leading to cross-firing between cylinders.
