Buzz
This comprehensive guide illustrates the process of adjusting valve clearance in an air-cooled VW Beetle. It's imperative to perform this task with a cold engine.
Steps
Determining Valve Clearance by Year:
- 1954-1960 (36HP): Intake - .004', Exhaust - .004'
- 1961-1965 (40HP): Intake - .008', Exhaust - .012'
- 1966 & Up: Intake - .006', Exhaust - .006'
Required Tools:
- 19mm/21mm wrench
- 13mm wrench
- Medium-sized flat-bladed screwdriver
- Feeler gauge (refer to specifications above)
- 2 new valve cover gaskets
To remove both valve covers, position the screwdriver beneath the center of the valve cover bails and pry downward. If equipped with AC, insert a shop rag through the bail and sharply snap both ends downward to loosen it. The bail will move downward, releasing tension on the cover. Once it stops dripping oil, clean it off the heat exchangers with a rag.
Remove the distributor cap by releasing the 2 clips. Insert the screwdriver between the clip and the cap, gently pry outward, and the clip will pop off the notches. Pull the cap up off the distributor, leaving the wires and rotor intact, and place it aside suspended by the spark plug wires.
Utilize the 19mm or 21mm wrench to turn the engine over by the generator/alternator pulley bolt. If the belt is loose, squeeze both sides of the belt as it enters and exits the upper pulley while turning the pulley with the wrench to increase tension.
Begin the valve adjustment with cylinder #1, located at the forwardmost position on the passenger side of the vehicle.
Position #1 cylinder at top dead center (TDC) by observing the distributor rotor. Rotate the engine until the rotor points directly at the notch on the distributor. Then, align the notch on the crankshaft pulley with the split in the center of the engine case to confirm TDC for cylinder #1.
Using the feeler gauge, measure the gap between the adjusting screw and the top of the valve for both intake and exhaust valves. If the gauge doesn't fit, loosen the lock nut on the adjustment screw, loosen the screw, and insert the gauge. If necessary, double-check TDC.
Once the gauge is inserted into the gap, gradually tighten the adjusting screw while sliding the gauge back and forth until there is noticeable resistance.
Hold the screw in place with a screwdriver and tighten the nut using the 13mm wrench. Ensure not to overtighten the lock nut; it should be securely tightened but not excessively so.
After completing adjustments for both intake and exhaust valves for cylinder #1, proceed to the next cylinder.
Each cylinder must be brought to TDC individually. At the rear of the car, use the 19mm or 21mm wrench to turn the engine counterclockwise, causing the crankshaft pulley to rotate 1/2 turn or 180 degrees. Another notch on the pulley will be located exactly 180 degrees from #1's TDC point. Align this notch with the split to bring the engine to TDC for cylinder #2.
Follow the adjustment procedure for cylinder #2.
Rotate the crankshaft an additional 1/2 turn counterclockwise until the original notch aligns with the case split, then adjust cylinder #3.
Repeat the adjustment process for cylinder #3.
Rotate the crankshaft another 1/2 turn counterclockwise and adjust cylinder #4.
Install the distributor cap, ensuring it clicks into the locating notch in the distributor housing, and secure the hold-down clips.
Remove any residue of the valve cover gasket from the cylinder head and valve covers.
- Insert the new gasket into the valve cover and position the cover on the cylinder head.
- Lift the bail until it clicks into the notch on the valve cover. A screwdriver may be needed to secure it completely.
Clean the underside of the engine, eliminating all oil residue, and recheck the oil level, adding as needed.
Initiate the engine and listen for pronounced tappet noise (clicking at idle). Presence of such noise may indicate misadjustment of one of the valves.
Inspect for any oil leaks.
Tips
Warnings
- Valve adjustment for each cylinder must occur at top dead center to avoid improper valve settings and potential engine damage during operation.
- Correct valve adjustment can last for tens of thousands of miles, with occasional adjustments needed for cylinders #3 due to increased thermal issues. Regularly check engine compression to ensure proper engine health. Engines with higher power outputs, such as those above 40 HP, may not achieve the same high mileage due to heightened thermal concerns, particularly in cylinder #3. Engines with 30 HP or 34 HP commonly achieve the highest mileages.
Regularly check compression to assess engine condition.
