Lack of Compression For
                                                       1998-2001 Audi 2.8L 5V Engines

The AERA Technical Committee offers the following information regarding lack of compression on 1998-2001 2.8L 5V Audi engines. Complaints for this condition include poor performance, hard starting or no start conditions. The cause of this condition may be carbon build-up on any of the engines thirty valves preventing it from sealing. 

Several measures are now available from Audi to resolve and help prevent reoccurrence of this condition. They include installing a hotter thermostat and performing an approved carbon cleaning process. At this time, only Wynn's X-Tend® V.I.C. Combustion Chamber Cleaner: Part No: 61510 (U.S.), Part No: 61512 (Canada) is authorized for use by Audi. 

A revised (hotter) thermostat was developed and installed in engines beginning after VIN 8DXA279411 for A4 vehicles and after VIN 4BXN116771 for A6 vehicles. The thermostat operating opening temperature increased from 87°C to 92°C. 

Engines should also be checked to verify the coolant temperature sending unit must be later than week 19 of 1998, i.e. 19/98. This will be stamped into the side of the sensor housing (arrow) as shown in Figure 1. Replace the sensor if necessary.
  Figure 1.

Note: Customers should be made aware that this type of carbon build-up may be due to fuels that do not contain a sufficient blend of detergents. Customers should be given the brochure Facts about Carbon and Fuel Quality (Literature No. W425527100) and advised to use Autobahn Gasoline Additive (ZVW 239 003), which is very effective in reducing and preventing carbon buildup, even if the fuel used does not contain a sufficient blend of detergents.

Audi also recommends installing a new set of spark plugs. Install new spark plugs Part #101000067 AA (NGK BKR6EQUPA) and a set of six 4-hole injectors, Part #078133551BA. The injector can be identified by their RED color as shown by the arrow in Figure 2.
   Figure 2. Four Hole Injector

It will also be necessary to change engine oil after carbon removal treatment and it is Important to note: DO NOT use 20W 50-engine oil - use ONLY factory-approved oil with proper viscosity.  

                                                                       The AERA Technical Committee

                                     Rear Main Crankshaft Seal Leak On
                                           Audi 2.0L, 2.2L, 2.3L Engines

AERA member shops have reported rear main oil seal leaks on the 2.0L, 2.2L, and 2.3L engines.  The engines are used in the Audi 80/90 and 100/200 cars.  

To verify that the engine oil leak is coming from the rear main seal, and not from the engine's valve cover, use florescent dye in the engine oil and a black light.

Audi has released an improved crankshaft seal, part number 068-103-051G to help correct this problem.  The new seal went into production after VIN # 44 LN026115 for the 100/200 models, and after VIN # 8A LA048000 for the 80/90 models.

Audi also advises using locking compound on the flywheel bolts to seal the crankcase.  The torque for the non-shoulder bolt is 55 lbs. ft.  The torque for the shouldered bolt is 74 lbs. ft. and Audi advises to always use new shouldered bolts.
                                                                         The AERA Technical Committee

                                        Hydraulic Valve Lifter Noise On
                                     1988-91 Audi 2.0, 2.2 & 2.3L Engines

The AERA Technical Committee has been informed of hydraulic valve lifter noise on 1988-91 Audi 2.0, 2.2 & 2.3L engines.  This noise may be heard both at engine start-up and during low engine RPM.  To reduce the possibility of undesirable lifter noise, Audi now supplies a new lifter, Part #034109309AD for all 4 & 5 cylinder engines.  

It is important to note that it may take as long as a week to purge all air from this new lifter after installation.  At the time of this publication, AERA is unaware of an aftermarket supplier of this lifter.

                                                                        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

                                         Main Bearing Saddle Repair Kits

The Cummins Engine Company has made main bearing saddle repair kits available for several engines.  These kits can be used to salvage cylinder blocks when a main bearing has spun and the main bearing saddle has been damaged.

Each kit contains an 1/8 drill bit, two hold down bolts (one for the lock ring and one for the other side of the saddle), a quantity of rivets and the appropriate number of repair sleeves.  Semi-finished or good used main bearing caps are also needed to complete the repair.

A main bearing saddle can be successfully repaired by following this procedure.
                                                                                                                            Remove the main bearing cap from the saddle to be repaired.  Using the appropriate align bore tooling remove .050 of material out of the saddle.  This will enlarge the main bearing bore by .100.

Clean the saddle and lock tang area.  Install the repair sleeve and align the lock tang slot of the sleeve with the one in the block.

From the repair kit, install the washer marked L on the lock tang side of the saddle.  Install the second washer on the opposite side.  Install the hold down screws and torque to 20 lbs.ft. (Figure 1).

Mount the 1/8 drill bit in a right angle drill, so that the drill extends 1/4 beyond the chuck jaws.

Using the 4 holes in the repair sleeve as a guide, drill through each of the holes into the saddle.  The proper hole depth is achieved when the chuck jaws contact the repair sleeve.

Clean the 4 holes and install the supplied rivets (Figure 2).  Peen the rivets until they are flush with the repair sleeve.

Remove the temporary hold down bolts and trim the ends of the repair sleeve so they are flush with the main bearing saddle.

Clean the main bearing bolt holes and install a good used or semi-finished main bearing cap.  Torque the main bearing bolts to specifications.

Using the appropriate align boring tools, refinish the main bearing housing bore to specifications.  Approximately .050 of material should be removed from the repair sleeve.
                                                                             
Main bearing bore repair kits or sleeves may also be available from several aftermarket sources.

                                                                        The AERA Technical Committee