Ford 2003 Mustang Workshop Manual page 845

required to obtain the highest reading.
5. Repeat the test on each cylinder, cranking the engine approximately the same number of
compression strokes.
Compression Test—Test Results
The indicated compression pressures are considered within specification if the lowest reading cylinder
is at least 75 percent of the highest reading. Refer to the Compression Pressure Limit Chart.
Compression Pressure Limit Chart
Maximum Minimum
Pressure Pressure
924 kPa 696 kPa
(134 psi) (101 psi)
938 kPa 703 kPa
(136 psi) (102 psi)
952 kPa 717 kPa
(138 psi) (104 psi)
965 kPa 724 kPa
(140 psi) (106 psi)
979 kPa 738 kPa
(142 psi) (107 psi)
933 kPa 745 kPa
(144 psi) (109 psi)
1007 kPa 758 kPa
(146 psi) (110 psi)
1020 kPa 765 kPa
(148 psi) (111 psi)
1034 kPa 779 kPa
(150 psi) (113 psi)
1048 kPa 786 kPa
(152 psi) (114 psi)
1062 kPa 793 kPa
(154 psi) (115 psi)
1076 kPa 807 kPa
(156 psi) (117 psi)
1089 kPa 814 kPa
(158 psi) (118 psi)
1103 kPa 827 kPa
(160 psi) (120 psi)
1110 kPa 834 kPa
(161 psi) (121 psi)
If one or more cylinders reads low, squirt approximately one tablespoon of engine oil on top of the
pistons in the low-reading cylinders. Repeat the compression pressure check on these cylinders.
Compression Test—Interpreting Compression Readings
Maximum Minimum
Pressure Pressure
1131 kPa 848 kPa
(164 psi) (123 psi)
1145 kPa 855 kPa
(166 psi) (124 psi)
1158 kPa 869 kPa
(168 psi) (126 psi)
1172 kPa 876 kPa
(170 psi) (127 psi)
1186 kPa 889 kPa
(172 psi) (129 psi)
1200 kPa 903 kPa
(174 psi) (131 psi)
1214 kPa 910 kPa
(176 psi) (132 psi)
1227 kPa 917 kPa
(178 psi) (133 psi)
1241 kPa 931 kPa
(180 psi) (135 psi)
1255 kPa 936 kPa
(182 psi) (136 psi)
1269 kPa 952 kPa
(184 psi) (138 psi)
1282 kPa 965 kPa
(186 psi) (140 psi)
1296 kPa 972 kPa
(188 psi) (141 psi)
1310 kPa 979 kPa
(190 psi) (142 psi)
1324 kPa 993 kPa
(192 psi) (144 psi)
Maximum Minimum
Pressure Pressure
1338 kPa 1000 kPa
(194 psi) (146 psi)
1351 kPa 1014 kPa
(196 psi) (147 psi)
1365 kPa 1020 kPa
(198 psi) (148 psi)
1379 kPa 1034 kPa
(200 psi) (150 psi)
1303 kPa 1041 kPa
(202 psi) (151 psi)
1407 kPa 1055 kPa
(204 psi) (153 psi)
1420 kPa 1062 kPa
(206 psi) (154 psi)
1434 kPa 1075 kPa
(208 psi) (156 psi)
1448 kPa 1083 kPa
(210 psi) (157 psi)
1462 kPa 1089 kPa
(212 psi) (158 psi)
1476 kPa 1103 kPa
(214 psi) (160 psi)
1489 kPa 1117 kPa
(216 psi) (162 psi)
1503 kPa 1124 kPa
(218 psi) (163 psi)
1517 kPa 1138 kPa
(220 psi) (165 psi)
1631 kPa 1145 kPa
(222 psi) (166 psi)
Maximum Minimum
Pressure Pressure
1544 kPa 1158 kPa
(224 psi) (168 psi)
1558 kPa 1165 kPa
(226 psi) (169 psi)
1572 kPa 1179 kPa
(228 psi) (171 psi)
1586 kPa 1186 kPa
(230 psi) (172 psi)
1600 kPa 1200 kPa
(232 psi) (174 psi)
1055 kPa 1207 kPa
(153 psi) (175 psi)
1627 kPa 1220 kPa
(154 psi) (177 psi)
1641 kPa 1227 kPa
(238 psi) (178 psi)
1655 kPa 1241 kPa
(240 psi) (180 psi)
1669 kPa 1248 kPa
(242 psi) (181 psi)
1682 kPa 1262 kPa
(244 psi) (183 psi)
1696 kPa 1269 kPa
(246 psi) (184 psi)
1710 kPa 1202 kPa
(248 psi) (186 psi)
1724 kPa 1289 kPa
(250 psi) (187 psi)
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