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CYL HEAD OIL GALLERY MODIFICATION |
Cylinder Head Oil Gallery Modification On
1976-85 Volvo 2.1 & 2.3L Engines
AERA members have reported a cylinder head oil gallery modification for Volvo 2.1& 2.3L engines. To enhance upper engine oiling, simply increase the diameter of the oil gallery hole to .563 (14 mm). To do so, requires the removal of the cylinder head and a drilling operation.
This engine design may allow sludge to accumulate in the oil gallery over a period of time if poor oil maintenance exists. To reduce the possibility of a seized camshaft from lack of lubrication at start-up, the following modification should be made to the cylinder head.
1. Remove cylinder head and locate the oil gallery feed hole on
the head gasket surface as shown in illustration below.
2. Obtain a .563 (14 mm) drill, and drill perpendicularly down
a distance of 1.770 (45 mm).
3. Do all other machine operations and clean thoroughly before
placing back in service.
4. Clean crankcase ventilation system and verify those
components are the manufacturer's current design.
The AERA Technical Committee |
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CRANKSHAFT/CAMSHAFT SEAL OIL LEAKS |
Volvo Crankshaft/Camshaft Seal Oil Leaks
Possible oil leaks around the crankshaft, camshaft or other engine gaskets may be due to a clogged flame trap in the PCV system. This does not seem to happen on turbocharged models.
The plastic Y-shaped flame trap is located in the PCV apparatus and may become clogged if engine oil is infrequently changed. Low grade or inexpensive oil may also cause stoppage which allows internal crankcase pressure to build, thus forcing an oil leak. In some cases, the pressure will force the oil dipstick to pop out.
A clogged flame trap should either be cleaned or replaced, says Volvo, and normal maintenance calls for routine cleaning of the trap every 15,000 miles.
The AERA Technical Committee |
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COMPRESSION PRESSURE QUICK REFERENCE CHART |
Quick Reference Compression Pressure Chart For
Gasoline Engines
The AERA Technical Committee offers the following information regarding acceptable compression pressures for gasoline engines. This information should be used when considering the mechanical condition of an engine during engine diagnosis. In most instances, specific values for acceptable engine compression pressure are not listed in service manuals. Most often, the only reference to compression is less than 25% differential between the highest and lowest cylinder readings.
The chart below can be used as a quick reference tool to determine if the values obtained during a cranking compression test are acceptable. Of course the closer the values of each cylinder are to each other, the better the possibility of optimum engine performance there is.
Maximum PSI Minimum PSI Maximum PSI Minimum PSI
134 101 174 131
136 102 176 132
138 104 178 133
140 105 180 135
142 107 182 136
144 108 184 138
146 110 186 140
148 111 188 141
150 113 190 142
152 114 192 144
154 115 194 145
156 117 196 147
158 118 198 148
160 120 200 150
162 121 202 151
164 123 204 153
166 124 206 154
168 126 208 156
170 127 210 157
172 129 212 158
The AERA Technical Committee |
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REVISED CONNECTING ROD |
Revised Connecting Rods On
1988-89 Volvo 2.3L B230 Engines
AERA members have reported connecting rod failures in 1988-89 Volvo B230 engines. Rod failures include both bending and actual breakage. Because of the frequency of these failures, Volvo has redesigned the connecting rod for additional strength (See illustration). Engines manufactured as of the 1990 model year use the revised connecting rod.
The revised rod features a thicker beam and has increased in weight by 40 grams. The revised rod should only be installed in complete sets of four, Volvo Part #0271451-7 (four matched rods). Substituting a revised rod, Volvo Part #3531260-2, for the former design will cause an out-of-balance condition and possible engine failure.
The AERA Technical Committee |
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CYLINDER BLOCK & CRANKSHAFT CHANGES |
Cylinder Block & Crankshaft Change On
Volvo 1988 2.3L B230 Engines
Volvo Motors has changed the cylinder block and crankshaft on 1988 and later 2.3L B230 engines. The changes are related to the crankshaft main journal size and thrust location. Volvo also identifies 1988 and newer blocks by stamping K externally on the front timing case.
Crankshaft main journal diameters have increased in diameter to 2.4798-2.4803 (62.987-63.000 mm). The thrust bearing has been relocated to the rear main and uses a flanged type bearing. The thrust length on the crankshaft was also increased to a length of 1.398 (35.5 mm). Connecting rod journals remain unchanged at 1.9285-1.9293 (48.984-49.005 mm) in diameter.
Revising the crankshaft required the block main bearing bores be increased to 2.6378-2.6383 (67.000-67.013 mm) in diameter.
Years Main Journal Rod Journal Thrust Main Brg.
Used Diameter Diameter Location Housing
& Length Bore
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1985-87 2.1648- 1.9285- 1.142 2.3228-
2.1654 1.9293 @ #3 2.3236
1988-92 2.4798- 1.9285- 1.398 2.6378-
2.4803 1.9293 @ #5 2.6383
The AERA Technical Committee |
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ROD SIDE CLEARANCE |
Crankshaft & Connecting Rod Assembly Caution For
1980-1984 2.3L AQ151 & AQ171 Volvo Marine Engines
The AERA Technical Committee offers the following information regarding a connecting rod and crankshaft assembly caution for 1980-1984 2.3L AQ151 & AQ171 marine engines. This information is most useful when engine disassembly and reassembly personnel are different people.
These engines use a crankshaft and connecting rod combination that appears to be ?not right" when the connecting rods are assembled to the crankshaft. The reason for this concern is expressed in the photo below, as it appears there is excessive rod side-play. The view shown below is normal even though it shows approximately .125" clearance on each side of the rod.
Previous service information has been reported to be unclear as to the allowable side play for connecting rods. Illustrations? showing ?normal" rod side play is in most manuals has further confused the issue.
Volvo refers to this extra rod side clearance as a ?low friction" design and they use it in several of their automotive engines as well.
The AERA Technical Committee |
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NEW CYLINDER LINER O-RINGS |
New Cylinder Liner O-Ring Seals On
Cummins NH/NT 6 Cylinder Engines
Cummins Engine Company has released new O-ring seals for the cylinder liners in NH/NT 6 cylinder engines. The new seals are made of an EP material and have a smaller diameter cross-section.
The new seal replaces both the old center seal #3008998 and the old lower seal #183049. The new seal carries Cummins part #3032874 and is black in color with one blue dot.
The new O-ring seals are not to be intermixed with the former seals on the same liner. Cylinder liner deformation will result. You can use the former seals and new seals in the same engine as long as they are used in the correct combinations on each liner. The illustration below shows the correct combinations.
The AERA Technical Committee |
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OIL IN COOLANT |
Oil in Cooling System on
VW 1.5L & 1.6L Diesel Engines
AERA members have reported instances of engine oil in the cooling system on VW 1.5L diesel engines. According to AERA sources, the problem is related to a crack in the cylinder head bolt hole located near the oil gallery feeding the cylinder head.
The oil feed gallery in the block is located on one side of the center head bolt hole and a coolant jacket is on the opposite side of the bolt hole. Pressurized engine oil is diverted through a slot in the head gasket and is feed up the side of the head bolt to the cylinder head. The oil also follows the bolt back down to the bottom of the bolt hole. Should the crack in the head bolt hole extend to the coolant jacket, oil can mix with engine coolant.
This problem is generally found on engines equipped with 11mm head bolt holes. Later design engines utilize 12mm head bolts and do not exhibit this defect. At the time of this writing no successful repair procedure is available.
The AERA Technical Committee |
