Some engines require you manually adjust the valve lash every so often, sometimes 10,000 or 15,000 mile intervals. You do this using a feeler gauge, and often 2 common hand tools such as a box wrench, and a flat head screw driver. Refer to the specifications listed in your vehicle repair manual, or ask the dealer service department. If you have vehicle which uses hydraulic lifters, and it's a cold morning, you may experience a noise valve train until the vehicle is warmed up. This is because the hydraulic lifters get full of gunk over time from the oil cooling in them. Eventually this leads to them needing to be cleaned, or replaced all together. It is best to take care of such issues rather quickly, as valves not opening properly may lead to burnt, or cracked valves.
Collapsed hydraulic valve lifter? Rocker arm (valves) need adjusting?
It is cheaper than replacing the lifter
Not that familiar with Jeeps, but you could have a collapsed lifter, or you might have a rocker arm out of adjustment.
The most common problem would be a valve lifter not pumping up. Of more concern would be the valve seat in the #4 cylinder going bad. Escorts have had this very common problem for years.
Worn valve train parts due to high mileage, lack of maintenance, abuse or contaminated motor oil (coolant mixing with oil).
If the noise is from the carb or(FI) it's a intake valve-OR a pumped UP hydralic lifter could cause that-OR even a piece of Carbon STUCK under the Valve can cause it.OR a bad rocker arm and/or push rod.
Depending where the noise was coming from, but this question is most likely to be answered in this way. If you switched a valve off and the noise was coming before the valve in the pipes, that would indicate a burst pipe.
The thing that could cause a knocking noise in your car is the same thing that could cause it in all cars A rod that or a flat lifter. it all really depends on where the knock is if its higher and to the back of the motor, it could be a motor mount
that means you need more oil. it could also be a sticky lifter or slightly bent push rod or even the tappets out of adjustment
The float valve shutting off the water flow.
It can.
The only place that sound would come from would be a valve being closed. The only valve is the one in the tank. Replace the valve and this should eliminate that noise. To check this out try closing the water shut off part way and see if noise changes or goes away.