How to Measure Cylinder Pressure?
3 Answers
Install the cylinder pressure gauge onto the engine. First, warm up the vehicle by running the engine until it reaches normal operating temperature, maintaining the coolant temperature between 85 to 95 degrees Celsius. Remove all spark plugs or fuel injectors from the vehicle and ground the high-voltage wires. Fully depress the throttle to open the throttle valve completely. Screw the threaded pipe connector into the spark plug hole. Engage the starter for approximately two seconds, then read the pressure value. Press the one-way valve button to release pressure and reset the gauge pointer.
Last time my car engine was shaking, I checked the cylinder pressure myself, and it was quite simple. The method is to first let the engine warm up for about ten minutes to ensure everything is working properly. Then turn off the engine, disconnect all the spark plug wires, and use a cylinder pressure gauge to test each cylinder one by one. You need to screw the gauge into the spark plug hole, have someone press the accelerator or manually turn the key to start the engine for a few seconds, and let the gauge display the pressure reading. The normal value should be around 10 to 14 bar. If the reading is too low, such as below 8 bar, there may be issues like air leakage, worn piston rings, or valve problems. I usually record the readings for each cylinder and compare the differences. A significant difference indicates a problem with a particular cylinder. Wear gloves during the operation to avoid injury, and don’t forget to reconnect the spark plug wires afterward. This kind of check can save some money and help detect engine problems early.
As a car enthusiast, I enjoy tinkering with engine diagnostics like checking cylinder pressure. Prepare a cylinder pressure gauge, warm up the engine, then stop it. Remove the spark plug from each cylinder and screw in the gauge's adapter. Connect the gauge, crank or start the engine for a few seconds, and observe the pressure readings. The normal range is between 10 to 15 bar, with consistent values indicating good health; low readings may point to leaks in pistons, valves, or head gaskets. After testing, remember to clean any dust from the cables. This DIY is super affordable, and the tools can be found on Taobao. Whenever my car feels sluggish or consumes too much fuel, I run this test to save on repair costs. Always ensure the engine is cool before starting—safety first, as electrical sparks can ignite. It's quite addictive to try and offers deep insights into your car's condition.
