beak

This was done on a Mitsubishi Lancer Evolution 8, but the general rule of thumb should apply to most cars:

Tools:
Compression Tester (can get from Autozone ect.)
Socket Wrench
Socket Extender
10mm socket (for spark plug cover)
13/16 Spark Plug Socket
Torque Wrench


From the shop manual:

COMPRESSION PRESSURE CHECK M1111002600421

1. Before inspection, check that the engine oil, starter and
battery are normal. Also, set the vehicle to the following
conditions:

• Engine coolant temperature: 80 − 95°C (176 − 203°F)
• Lights, and all accessories: OFF
• Transaxle: Neutral

2. Disconnect the spark plug cables.

3. Remove all of the spark plugs.

4. Disconnect the crankshaft position sensor connector (located next to oil cap, a triangular connector).
NOTE: Doing this will prevent the engine control module
from carrying out ignition and fuel injection.

WARNING
Keep your distance from the spark plug hole when
cranking. Oil, fuel, etc., may spray out from the spark
plug hole and may cause serious injury.

5. Cover the spark plug holes with a shop towel etc. Crank the
engine for a few seconds to clear debris from a round the
spark plug holes. After the engine has been cranked, check
for foreign material adhering to the shop towel.

6. Install the compression gauge to one of the spark plug
holes.

7. Crank the engine with the throttle valve fully open and
measure the compression pressure.
Standard value (at engine speed of 250 r/min): 1,128
kPa (163 psi)
Minimum limit (at engine speed of 250 r/min): 951 kPa
(138 psi)

8. Measure the compression pressure for all the cylinders, and
check that the pressure differences of the cylinders are
below the limit.
Limit: 98 kPa (14 psi)

9. If there is a cylinder with compression or a compression
difference that is outside the limit, pour a small amount of
engine oil through the spark plug hole, and repeat the
operations in steps 6 to 8.

(1) If the compression increases after oil is added, the cause
of the malfunction is a worn or damaged piston ring
and/or cylinder inner surface.

(2) If the compression does not rise after oil is added, the
cause is a burnt or defective valve seat, or pressure is
leaking from the gasket.

10.Connect the crankshaft position sensor connector.

11.Install the spark plugs (Torque: 18 ft/lb) and spark plug cables.

12.Use the scan tool (or disconnect battery for 1 min) to erase the diagnostic trouble codes.

NOTE: This will erase the diagnostic trouble code resulting
from the crankshaft position sensor connector being discon-
nected.

__________________
Don't fry bacon when you're naked.

96 EK Hatch 343whp, and 245ft/lb torque at 11psi - Stock GSR Motor

GSRTURBO

great writeup mang

__________________
-Brandon
DD '92 Civic VX - B18C1 swap - 8spi t04r

dsm_tuner260

if i was to do a compression test on my car would it tell me if i have a snapped rod.

__________________
if its not built to be beat on it's not built right.

EuroEclipse

the sound of the motor shitting itself would tell you that. and the fact it won't start. and you probably have metal shavings/chunks in the oil.
how in the hell did you snap a rod, if you did?