- Improper installation: If the intake manifold gaskets were not installed correctly, it could cause the engine to knock.
- Damaged gasket: If the intake manifold gasket was damaged during installation, it could also cause the engine to knock.
- Vacuum leak: If there is a vacuum leak, it can cause the engine to run lean and knock.
- Damaged valve: If a valve is damaged, it can also cause the engine to knock.
Here are some additional things you can check:
- Check the spark plugs to make sure that they are properly torqued and not loose.
- Listen for any other unusual noises coming from the engine. If you hear any other noises besides the knocking sound, it could be another problem that needs to be addressed.
- Have a qualified mechanic inspect the engine to determine the exact cause of the knocking sound.
