What is the method for measuring cylinder pressure?

[AlyssaLynn]

The method for measuring cylinder pressure is as follows: 1. Run the engine until it reaches normal operating temperature, with coolant temperature between 85-95 degrees; 2. Remove all spark plugs or fuel injectors, and ground the high-voltage wires; 3. Fully depress the throttle to open the throttle valve completely; 4. Press the conical rubber adapter of the cylinder pressure gauge tightly into the spark plug hole of the cylinder being tested, or screw the threaded adapter into the spark plug hole; 5. Crank the starter for 2-3 seconds, read the measurement after the pointer stabilizes, then press the one-way valve to reset the pointer. Perform at least two measurements per cylinder; 6. Additionally, during the second measurement, you can inject a small amount of engine oil (20-30ml) into the spark plug hole before measuring the cylinder pressure again. If the cylinder compression pressure remains the same after oil injection, it can be determined that there is valve leakage.

[VonHolden]

I've been repairing cars for many years and am used to working with a cylinder compression tester. The car must be warmed up to normal operating temperature first, otherwise the readings won't be accurate. Remove all spark plugs and screw the tester tightly into the spark plug hole. Get an assistant to floor the accelerator or use a remote starter to crank the engine without ignition. Watch the pressure reading pop up on the gauge - you need to test each cylinder thoroughly. Normal readings typically range between 100-150 psi. If any cylinder shows significantly lower pressure (about 20% less than others), it usually indicates worn piston rings or faulty valve seals. Then I often perform a wet test by adding a bit of engine oil and retesting to see if pressure improves - this confirms whether it's ring leakage. If the difference is too large, repairs should be done promptly to prevent more serious engine damage. Basically, even compression readings mean the engine runs well. Don't skip regular testing.

[StRhett]

Hey, I'm a car enthusiast and learned cylinder pressure testing when my own car had issues. Bought a compression tester, pretty cheap. First, drive the car around to warm it up, then stop and pull out the spark plugs. Attach the tester, open the throttle all the way, and crank the engine to make it turn. Watch the needle on the gauge—last time my car's third cylinder was only 50 psi while the others were at 130, clearly a problem. Found out it was a leaking valve, and after fixing it, the power came back. Since learning this, I test the pressure balance every six months to prevent small issues from becoming big ones. DIY saves money and gives a sense of achievement, just be careful not to get burned by hot parts during testing. Key is to record data for comparison—if the difference is too big, act fast.

[LeEdward]

When I first started learning about car maintenance, I asked the master about the cylinder pressure test method. They said it's simple—just use a test gauge inserted into the spark plug hole. After warming up the car, remove the spark plug, connect the gauge, and start the engine to measure. But remember to fully open the throttle to let air in. After testing, read the values; normal readings should be within the standard range and consistent. The first time I tested, I didn’t understand the high and low readings, only remembering that a big difference could cause strange noises or lack of power in the car. Later, I learned that low pressure means air leakage, like when piston rings are damaged. Just prepare the tools and safety gear before starting—don’t overcomplicate it. Regular testing helps maintain pressure balance, keeping the car running longer.

[DelEleanor]

As an experienced driver, I prioritize safety first. Cylinder pressure imbalance can lead to engine failure and high-speed loss of control. The detection method involves using a pressure gauge inserted into the spark plug hole. Warm up the car for 10 minutes, remove the spark plug, connect the tester, start the engine, and rotate to measure the pressure. Each cylinder's pressure should be close, with minor differences around 140 psi. I once ignored a 30% reading difference and ended up breaking down halfway, nearly causing an accident. Since then, I perform maintenance checks every 5,000 kilometers. Professional shops use compression testers, but you can also buy a kit to do it yourself. Unusual noises or difficulty starting the engine are signs to check the pressure. Maintaining even pressure reduces the risk of unexpected incidents.