Engine: Compression Test

A compression tester is a gauge that screws into the spark plug holes so that cylinder compression can be measured. For the most part, they are universal for gas power engines.

This particular model can be purchased from Sears for around $60.00.

Steps to Perform a Compression Test

• Next you need to disable the cars ability to start this can be done one of two ways.

1. Remove the ECI fuse
2. Disconnect the coil wire for SOHC. Disconnect the Crank Angle Sensor (CAS) for DOHC.

• You have to pull the intake manifold off to do the back 3 cylinders. If you just do the front just pull out the intake arm then have someone hold the Throttle Body wide open.
• Remove the Spark Plugs.
• Crank the starter for about 5 Compression strokes (you can see the gauge move 5 times).

Then it will either tell you a high number (good) or a low number (very bad). It is possible to have good numbers on some cylinders, but one or more with a very low number.

Standard Compression Numbers (PSI)

	Standard (New)	Lower Limit
SOHC	171	127
DOHC NA	185	139
DOHC TT	156	115