How to Adjust the Valves of a Five-Cylinder Engine?
2 Answers
Five-cylinder engine valve adjustment method: First, slightly loosen the lock nut on the rocker arm, then use a screwdriver to turn the adjustment screw as needed—turning it downward reduces the clearance, while turning it upward increases the clearance. Adjust until the rocker arm and valve are in contact with the feeler gauge but can still move slightly. Then, hold the adjustment screw in place with the screwdriver and tighten the lock nut. Next, move the feeler gauge and rotate the crankshaft for rechecking until all valve clearances are correctly set. Car valves, also known as throttle valves, are responsible for delivering fuel into the engine and expelling exhaust gases. Traditional engines have only one intake valve and one exhaust valve per cylinder. This design is relatively simple, easy to maintain, and performs well at low speeds. However, its drawback is difficulty in increasing power, especially at high speeds where the air intake efficiency is low and performance is weaker. To improve intake and exhaust efficiency, multi-valve technology is now commonly adopted.
Adjusting the valves on a five-cylinder engine, I believe the key lies in the sequence and preparation. The firing order of a five-cylinder engine is typically 1-2-4-5-3, so the operation must be done step by step. The engine must be cold when starting—safety first—wear gloves to avoid burns or oil contamination. Prepare a feeler gauge, wrench, and thickness gauge, then remove the valve cover. Next, rotate the crankshaft to locate the top dead center (TDC) position of each cylinder during the compression stroke—this can be confirmed using the ignition coil signal or by observing piston movement. At this point, measure the clearance of the intake and exhaust valves; the standard value is approximately 0.2mm to 0.3mm, but refer to the manual for specifics. If the clearance is incorrect, loosen the adjustment screw, set it correctly, and then tighten it. After checking all valves, reinstall the cover and start the engine for testing, listening for smooth operation. This process requires attention to detail—haphazard adjustments may lead to engine noise, increased fuel consumption, or even valve damage in severe cases. Regular maintenance can save significant costs.
