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How to unstick engine valves – A simple guide to fix stuck valves

How to unstick engine valves

If you are hearing an unpleasant noise from your engine that’s not really like any other, it is likely that your engine valve is stuck. This usually happens due to the accumulation of sludge between the valve and the guide. There’s a stem between these two parts where sludge usually gets through. When this happens, the valve won’t move as usual. It will face quite a few problems, especially when the engine is cold (in the mornings). Once it heats up, things can get better but that’s not a permanent solution.

Those who haven’t used their vehicle in days or weeks will face even tougher problems because over time, sludge dries up and hardens, making it impossible for the valve to move.

If this is bothering you as well, our guide will help you solve the problem.

How to unstick engine valves

Below are the steps you should follow:

If the sludge has not hardened

Buy a good sludge remover and use it to dissolve the sludge. Most sludge removers work with the engine oil. You should add it to the oil and then start the engine. After some time, you should discard the oil. 

Please remember that this only works if the sludge is not too hard. In other words, if you have been using your vehicle regularly, this will work. 

If the sludge is stubborn

In most cases, the aforementioned method will work. If it doesn’t do the trick for you, please follow this method.

  1. Remove the engine head after removing the cover
  2. Locate the camshaft and rotate it
  3. Use penetrating oil to soak the stem of the valve – you may need to tap the valve for the oil to reach all desired places
  4. Now, close the engine valve. You may need to use a brass hammer to accomplish this because valves usually don’t go back in place easily.
  5. Repeat this process for a few days.

Please note that this process has been tried and tested by experts. It does not work immediately and takes its time. So, it is important to be patient and not try to rush. You will see a significant improvement in a week or so.

People also ask

1) Can seafoam fix a stuck valve?

Yes, a can of seafoam can indeed fix a valve but we recommend that you use it only if the valve is not unsticking after following the steps above.

2) Does seafoam ruin spark plugs?

This is a common concern and the answer is quite relieving. Seafoam does not affect spark plugs because they clean themselves. 

3) What happens when a valve sticks? 

You will hear a rattling noise when you try to start the engine. This is because a stuck valve increases cylinder temperature.

4) What causes a valve to stick?

The most common reason that we noted so far is the usage of fuels with high lead content. Not changing the oil regularly is another factor.

5) How much does it cost to replace a valve?

It can easily cost around $1000 to $2000 to replace the engine valve. This is why, it is ideal to ensure its health and take measures to prevent sticking.

6) Will seafoam hurt the engine?

No, seafoam is harmless.


We hope our article provided the required information and tips on successfully unsticking a valve. We would love to hear your thoughts on this as well. So, don’t forget to leave a comment.

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