How to Adjust Valves

Usually in all cars, the valve needs to be adjusted as a part of regular servicing of the car. If the valves of the car are not adjusted properly, it might stop the car engine’s function, or else the car won’t run smoothly. The details of adjustment of the valve are mentioned on the sticker inside the engine bay. Alternatively, you can refer to the car manual to find out the same. To know how to adjust valves, read the instructions given below.

You will need some equipments to adjust the valves of the car such as:

  • Wrenches – open ended
  • Feeler gauges
  • Ratchet & Socket set
  • Flat-head screwdriver

How to adjust valves?

  • Detach the spark plug wires, the cover of the timing chain and the valve. Once these covers and wires are removed, you can see some marks over the camshaft sprocket. These are timing marks.
  • Using the half inch socket over the crank bolt, rotate the engine, such that piston number one stays at TDC – top dead center. To check the position of the piston on TDC, remove spark plug number one. Slowly turn the crank and while doing this, insert the longest screwdriver in the hole of the spark plug.
  • The ‘top dead center’ or TDC is the point at which the screwdriver stands high, just before the piston starts going down. When it is at TDC, the camshaft pulley should be straight and the timing marks should be aligned with the TDC marks. You can use a flash torch to check the position exactly.
  • Start with cylinder number one, and check it for valve clearance. There is a lock nut holding the adjuster at its position. Loosen this nut, choose a proper thick feeler gauge between the clearance adjuster and the valve stem.
  • Using a flat head screwdriver, settle the adjuster at a proper place, by inserting the screwdriver in the slot of this adjuster, and with the other hand using a wrench, fit the lock nut tightly again.
  • When the clearance is perfect, the feeler gauge can be removed easily, but the resistance is felt while pulling the gauge out. If the gauge cannot be removed, the setting is not correct, and very tight. The exhaust and intake valves’ settings vary, and your user manual will give you the details about these settings.
  • Now check the valves at the third position. The Crankshaft here has to be rotated 180 degrees to the left, or anticlockwise. Turn the camshaft by a quarter turn. There is an ‘UP’ mark seen over the pulley of the camshaft, which points at the motor’s exhaust side. Again here, check the exhaust, and intake clearance of the valves as mentioned above.
  • Now move on to the valves at the fourth position. Again the crankshaft has to be turned anticlockwise by half turn and camshaft by quarter turn. This time the ‘UP’ mark seen on the camshaft pulley will point down. Again check the clearance of valves as mentioned above.
  • Lastly, check the valves at the second position. Again rotate crankshaft anticlockwise by half turn and camshaft by quarter turn. This time the ‘UP’ mark will point towards the ‘intake’ of motor. Check the valve clearances in similar manner.
  • Once the valves’ clearances are checked, replace the cover and wires as they were positioned.

The procedure is tough; however, if you have some knowledge about the parts of the engine and have had an experience at this, it will be simple for you. If you are doing it for the first time, ask someone who has experience at this, to help you with it. Knowing how to adjust valves is good because you need to make these adjustments from time to time, and will not have to depend on your mechanic to sort it out.


Related Content:

  1. How to Adjust Timing Belt
  2. How to Adjust Lifters
  3. How to Adjust a Water Pressure Regulator
  4. How to Adjust a Door Closer
  5. How to Adjust Rockers Arm

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