Execute A Compression Test Around The Engine Inside A Chevrolet Cobalt

The Chevy Cobalt comes with a principles 4-cylinder engine in three sizes, 2.0 L, 2.2 L and 2.4 L. When valves, piston rings and cylinder walls wear away, the engine loses competence, burns oil or runs poorly. A compression appraisal is a constructive part used to diagnose these problems without tearing apart the engine.


1. Turn on the engine in the Chevy Cobalt and let it heated up in that performing a compression examination on a arctic engine Testament contribute inaccurate results. The battery must be in crack dispute for the elimination. Arrange the corresponding for the other three cylinders in the Chevy Cobalt.4. Compare the four compression numbers to manufacturer specifications too as each other. The compression ratio for the engine of a Chevy Cobalt depends on the engine size.

Be definite to conclude this before testing to avoid electrical shock.

3. Subsume the compression tester into one of the four Glimmer plug holes and Eccentric person the starter to rotate the engine. After building compression in the cylinder, engross down the compression amount. Once the engine is melting, turn it off before proceeding with the analysis.2. Remove the Glimmer plugs and disable the ignition course by pulling the coil wire or disabling the ignition coil.

It is 9.5:1 for a 2.0 L engine, 10:01 for a 2.2 L engine and 10.4:1 for a 2.4 L engine. Ideal readings fall within 15 psi of the recommended number and within 10 psi of each other.

5. Repeat the compression test on any of the cylinders showing a low reading. However, add a capful of motor oil to the cylinder before doing so. If this procedure results in a higher test number, then you have worn cylinder walls or piston rings. If the number doesn't change, then you have worn valves or valve seats.