How to Adjust an Exhaust Valve

An exhaust valve that is either too tight or too loose can cause several engine problems. It either causes the engine to lose power or to lose efficiency. Like the intake valve, the exhaust valve also needs to be adjusted correctly to ensure maximum engine performance.

Tools and Materials

  • Screwdriver
  • Socket wrench set
  • Toque wrench
  • Protective gloves
  • Car jack
  • Jack stand
  • Feeler gauge
  • Factory recommended clearances table

Step 1 – Preparation

To work on the valves, it is necessary get one wheel elevated. Use a car jack to elevate one side of the car. Place a jack stand underneath the side of the car elevated so that it can rest on the stand instead of the floor surface.

Step 2 – Remove the Elevated Wheel

Removing the wheel allows the engine to be moved manually thought the crankshaft. First, remove the lug nuts from the wheel then wiggle it a little bit until it comes off.

Step 3 – Ensure Safety

When working with cars, always wear protective gloves to protect the skin from contact with carcinogenic chemicals. Keep in mind that the oils, the grease, and the solvents in the car may cause damage to the body when accidentally ingested, so be safe.

Step 4 – Locate the Exhaust Valves

Refer to the car’s manufacturer’s manual when having trouble locating the valves. The exhaust valves should be hidden by a valve cover. The cover is usually secured by four lock nuts. Remove the lock nuts including the metal washers and rubber gaskets in between them with the correct socket wrench. Set these aside in a group. Pry open the cover with a screwdriver and set it aside.

Step 5 – Set the Cylinder Head on Top Dead Center

The cylinder head should be aligned on top dead center to allow the exhaust valve to be adjusted. There should be a timing mark on the crankshaft that can be useful for this alignment. Rotate the shaft until the notches on the exhaust valve cam are aligned with the head. Check out other methods on alignment if necessary.

Step 6 – Check the Clearance on the Valve

Check the distance on from the adjusting screw and the valve using a feeler gauge. Record the measurement for future use. Use a wrench to loosen the retaining nut securing the adjusting screw.

Step 7 – Adjust the Clearance for the Exhaust Valve

Use a screwdriver to tighten the adjusting screw on the feeler gauge until the gauge cannot be pulled. Loosen it a bit so that gauge can be moved in between the valve and the screw. Tighten the nut and check the distance on the clearance again. The retaining nut may cause the clearance to change so make sure to measure it always. Using a table on factory recommended clearances, adjust the clearance on the valve to the correct settings.

After adjustments, put the cover on the valves back on. Apply a little sealant around the cover to keep it tight. Install the wheel back on and remove the jack stand.