Engine Compression

Warm engine to normal operating temperature. Remove all spark plugs. Disconnect ignition coil primary wire connector. Hold throttle plate fully open. Crank engine and note compression pressure.

COMPRESSION RATIO

Application		Specification
B2500		9.2:1
B3000		9.0:1
B4000		9.0:1
Millenia
2.3L		10.0:1
2.5L		9.2:1
MPV		8.5:1
Protege
1.5L		9.4:1
1.8L		9.0:1
626
2.0L		9.0:1
2.5L		9.5:1

COMPRESSION SPECIFICATIONS

Application

Minimum psi (kg/cm² ) @ RPM

Standard psi (kg/cm² ) @ RPM

B2500

N/A

⁽¹⁾

B3000 & B4000

N/A

⁽¹⁾

Millenia ⁽²⁾

2.3L

121 (8.5) @ 250

164 (11.5) @ 250

2.5L

132 (9.3) @ 300

189 (13.3) @ 300

MPV

121 (8.5) @ 300

164 (11.5) @ 300

Protege ⁽²⁾

1.5L

146 (10.3) @ 300

195 (13.7) @ 300

1.8L

139 (9.8) @ 300

185 (13.0) @ 300

626 ⁽²⁾

2.0L

119 (8.4) @ 300

171 (12.0) @ 300

2.5L

141 (9.9) @ 250

203 (14.3) @ 250

⁽¹⁾	Lowest compression reading should not be less than 75 percent of highest compression reading.

⁽²⁾	Difference between cylinders should not be more than 28 psi (2.0 kg/cm² ).