When a Geo Underground runs poorly, tearing apart the engine to study what happens inside is a abundance of arduous drudge. Running a compression evaluation on Everyone of the Geo Underground's cylinders (three or four depending on the engine extent) is a more appropriate design of checking for worn absent parts and earnest engine problems. A compression examination is breakneck and requires actual hasty skill or exclusive Accoutrement.
Instructions
1. Scorching up the engine in the Geo Underground before doing the compression proof. The battery Testament essential to spin the engine indefinite times so be confident that it is in exceptional context. An engine compression assessment on a algid engine Testament not give accurate results.
2. Shut down the engine once it's warm and remove all three spark plugs from the 1.0L engine. If this causes the compression number to increase, the cylinder has worn walls or worn piston rings. If the number is the same, worn valves or worn valve seats are the problem.
3. Choose one of the spark plug holes and insert the compression tester. Rotate the engine by cranking the starter so that compression builds because cylinder. Write down the compression number since you will use it later.
4. Move on to the next spark plug hole and repeat this procedure for each of the cylinders, three or four depending on the engine size. Compare these numbers to the manufacturer specifications. An ideal compression ratio for either size engine in a Geo Metro is 9.5:1. The test readings should fall within Fifteen PSI of this number further as Ten PSI of each other.
5. Repeat the test on any cylinders that have a low reading. Add a small amount of motor oil to the cylinder before performing the test again. If the Geo Metro contains a 1.3L engine, there will be four spark plugs. This spark plug removal allows the starter to spin the engine freely. Disable the ignition coil or disable the ignition system by pulling the coil wire.
