Table 1. Engine Troubleshooting Procedures - continued

TM 9-2320-361-24-1

0008 00

MECHANICAL SYSTEMS TROUBLESHOOTING - DIRECT SUPPORT (Contd)

Table 1. Engine Troubleshooting Procedures (Contd).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

6. Crank engine through at

11. EXHAUST COLOR

least five compression

BLUE DURING

strokes or until gauge stops

NORMAL

rising.

OPERATION (Contd)

7. Record cylinder number and

maximum gauge reading.

8. Remove gauge from number 1

cylinder and repeat steps 1

through 7 for remaining

cylinders. This is known as

a dry test.

9. Add 1 to 1 oz (2944 ml) of

clean engine oil through plug

port for each cylinder before

connecting compression

gauge. Repeat steps 5

through 7. This is known as a

wet test.

10. Record gauge readings for

wet test next to dry recorded

test results for each cylinder.

Test 2. Analyze compression test

results.

Compute compression loss for dry

test for each cylinder compared to

cylinder with highest reading using

the following formula:

NOTE

The sample cylinder reading is the

reading from any cylinder other than

the highest compression cylinder.

Highest

Sample

Cylinder Reading Cylinder Reading x 100 = % Compression Loss

Highest Cylinder

Reading

1. If one or more cylinders has

If pistons, piston rings, or cylinder

an 810% or greater

liners are damaged, replace engine

compression loss in dry test,

(WP 0046 00).

but improved to acceptable

(less than 8%) loss in wet

test, then pistons, piston

rings, or cylinder liners

problem is indicated.

2. Remove heads and inspect

If damaged, replace engine

pistons, piston rings, and

(WP 0046 00).

cylinder liners for breaks,

wear and scoring.

0008 00-6