How to adjust the valves of a FAW 11-liter engine?
2 Answers
Loosen the adjusting nut on the rocker arm, turn the adjusting screw, and manually rotate the valve pushrod. When you feel slight resistance, tighten the locking nut to complete the adjustment. When adjusting the valves on a single-cylinder diesel engine, disconnect the high-pressure fuel pipe joint of the fuel injector. When the flywheel is rotated to the point where diesel in the high-pressure pipe stops flowing, you can then stop rotating the flywheel and proceed with the adjustment.
A few years ago, I helped a friend adjust the valves on a Jiefang 11-liter diesel engine. This task requires careful attention. The engine must be completely cooled down before starting, otherwise, it can burn your hands and easily damage parts. First, disconnect the spark plug wires to ensure the engine doesn't start. Locate the crankshaft pulley and slowly turn it to a specific position using a wrench, ensuring both the intake and exhaust valves of the first cylinder are closed—this is crucial. Then, use a small feeler gauge (around 0.3 mm thick) to measure the valve clearance. The intake valve should be approximately 0.25-0.30 mm, and the exhaust valve 0.35-0.40 mm. If it's out of spec, adjustments are needed. The adjustment screw is on the rocker arm—loosen the lock nut with a wrench, turn the adjustment screw in or out, and tighten it once set. Take it step by step; don’t rush. After adjusting, start the engine and listen for smooth operation. If there’s excessive hissing from leaks, further adjustments are required. Incorrect valve clearance can lead to burnt valves or increased fuel consumption, so I always recommend having someone assist to avoid mistakes. Checking during regular maintenance can prevent major issues.
