Oil Starvation Of The Cylinder Head On
                                        1986-89 Acura 1.6L Engines

AERA machine shop personnel are reminded to thoroughly clean the vertical oil passage in the cylinder block when rebuilding 1986-89 Acura 1.6L engines.  This engine also uses an oil control jet at the block deck in that vertical oil gallery.  It too must be removed, cleaned and free of obstructions.  Note that the opening of the control valve is only .040 (1.02 mm) in diameter (see illustration).

Anytime the cylinder head is removed from the engine, the oil control jet needs to be removed from the gallery.  Once removed the vertical gallery should be flushed from the lower oil supply gallery.  Pressurized air will work if the engine has been disassembled.  If the engine has not been removed from the vehicle, oil can be forced through the gallery by turning the engine with the starter.  Be sure to install a new gasket under the control jet before positioning the cylinder head gasket and mounting the head.

Failure to reinstall the oil control valve will force too much oil into the cylinder head.  This may render the valve seals ineffective or overwhelm the PCV system, causing excessive oil consumption.  
 
                                                                             The AERA Technical Committee

                                              Snapping Noise On
                                       1990-91 Acura 1.8L Engines

The AERA Technical Committee has been advised of a snapping noise on
1990-91 Acura 1.8L engines.  The best description for this noise is a sharp snapping sound, similar to the sound of spark plug wire arcing.  The cause for this unusual noise is not obvious, but may be uneven cylinder head torque.

Inappropriate torque may permit the cylinder head to move as the engine reaches operating temperature.  If this noise is detected and o other cause can be found, verify the cylinder head bolt torque with this procedure: 

      1.   Allow the engine to completely cool and remove both camshafts.
      2.   In reverse sequence loosen cylinder head mounting bolts, one bolt at a 
            time, then torque each bolt immediately to 7 ft. lbs.
      3.   After all bolts have been tightened to 7 ft. lbs. in sequence, tighten all 
            bolts to 22 ft. lbs. Finally, advance the head bolt torque to 43 ft. lbs,
            then 61 ft. lbs.
      4.   Reinstall the camshafts and adjust valve clearance to .006 for intake   
            valves and .007 for exhaust valves.

                                                                             The AERA Technical Committee

                                              Engine Ticking Noise On
                                      1999-2003 Acura 3.2 & 3.5L Engines

The AERA Technical Committee offers the following information regarding an engine ticking noise on 1999-2003 Acura 3.2& 3.5L engines. This noise occurs after the cylinder head has been removed for machining and reinstalled on the engine. The information contained in this bulletin applies to engines reassembled with original equipment head gaskets.

Inadvertently the incorrect cylinder head gaskets may have been installed on this engine. Some cylinder head gaskets were mispackaged with the incorrect cylinder bore diameter in the gasket. Instead of getting the correct 3.5040" (89 mm) bore gasket, gaskets with a 3.3858 (86 mm) bore were packaged for this engine. 

The ticking noise that is heard is actually the pistons hitting the head gaskets as they approach top dead center (TDC). If the cylinder head gasket, as shown in Figure 1 below has a P8C stamped on it, the incorrect gasket was installed. The correct gasket should have the letters PGE stamped on it, Part #1255-PGE-A01.
 
Acura Part Numbers
Front Gasket Set Kit Part #06110-PGK-A11
Rear Gasket Set Kit Part #06120-PGK-A11

                                                                        The AERA Technical Committee

                                                 Oil Consumption On
                                      1986-94 Acura 1.6, 1.7 & 1.8L Engines

The AERA Technical Committee offers information on oil consumption on 1986-94 Acura 1.6, 1.7 & 1.8L engines. Acura considers oil consumption when the rate is in excess of one quart to one thousand miles traveled. This engine uses a 
metered oil supply to the cylinder head by means of a removeable metal oil jet located in the deck of the cylinder block.

The oil jet meters a certain amount of engine oil to the cylinder head components. During the removal process of the cylinder head, it may stick to the head and be misplaced during cleaning and handling. If the oil jet, Part 
#15140PM3000, is not reinstalled during assembly, excessive amounts of engine oil will enter the cylinder head. This additional amount of oil will then collect under the valve cover and overwhelm the valve stem seals. The oil may also 
enter the PCV system if the level becomes high enough. In either case, oil will enter the combustion process or the exhaust system causing oil loss.

Some AERA members increase the opening size of this orifice slightly, anytime the cylinder head has been removed from the block. Drilling the existing restrictor to .062 (1.575 mm) in size will increase the volume of oil to the cylinder 
head and camshaft. That procedure has been beneficial during cold starts when ambient temperatures are very low.

Increasing the orifice hole size slightly should not overwhelm the cylinder head with oil, providing all other oil clearances are within specifications. 

                                                                                The AERA Technical Committee

                                      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

                                               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

                                        Cylinder Head Specifications on
                                              Case 207 Diesel Engines

The following cylinder head specifications should be considered when remanufacturing Case Model 207 diesel engine cylinder heads.

The minimum cylinder head thickness has been established at 3.968 with a new head measuring 4.000 +/- .005.  Heads are measured from the deck surface to the rocker cover rail.

Valve recession should be checked and adjusted if necessary to a maximum recession of .015, below the deck surface, for both intake and exhaust valves.  Valves on new cylinder heads are generally flush with a +/- .005 tolerance.

                                                                       The AERA Technical Committee