Timing Chain Rattling Noise On
                                                 1999-2002 Suzuki 2.5L Engines

The AERA Technical Committee offers the following information regarding a timing chain rattling noise on 1999-2002 Suzuki 2.5L engines. This noise comes from the front of the engine behind the timing cover and is normally heard the loudest when the engine is cold. Vehicles that are affected are the Grand Vitara & XL-7.  
There are 3 timing chain tensioners on this engine and causing this problem is the number 1 timing chain tensioner that is not properly adjusted. In order to fix this problem, Suzuki recommends replacement of the number 1 tensioner only as shown in the Figure 1 below. The new tensioner is being offered under Part #12831-85FA7. If there is a tensioner noise for the first 5 seconds of engine operation, Suzuki considers this normal under engine operation. 

After installation of the tensioner, properly clean the sealing surface on the timing chain cover, crankcase, cylinder block and cylinder heads for installation. Apply sealant ?A" Suzuki Bond 1207F (Part #99000-31250) to the timing chain cover sealing surface as shown in Figure 2. Apply sealant ?B" Suzuki Bond 1207B (Part #99104-31140) to the mating surface of the cylinder block and head. Use a plastic scraper as a jig to force the sealer into the air gap formed between the cylinder block, head and head gasket as shown in Figure 2A. 

NOTE: Failure to perform this step will result in an oil seepage that will migrate down the front of the block and be diagnosed as a crankshaft seal leak. 

                                                                          The AERA Technical Committee

                             Camshaft & Crankshaft Timing Chain Alignment For
                                    1998-2003 Suzuki 2.5L, DOHC V-6 Engines

The AERA Technical Committee offers the following information regarding camshaft and crankshaft timing chain alignment on 1998-2003 Suzuki 2.5L, DOHC V-6 engines. These engines are used in the Grand Vitara vehicles.  Suzuki uses an intricate timing chain arrangement, which is different from the right to left bank. 

To correctly install the numerous chains and gears on this engine, start on the right hand bank or passenger side and follow the steps and diagrams listed below.  

1.	Install the right hand (RH) camshaft-to-camshaft timing chain tensioner adjustor as viewed in figure 1, torque bolts (a) to 8 ft/lbs.
2.	Install the RH second timing chain, matching alignment marks of the yellow or silver links with camshaft sprockets as viewed in Figure 2.    
3.	Install the crankshaft sprocket and turn the crankshaft keyway up (12 o?clock position) as in Figure 3.
4.	Align the RH intake camshaft timing mark as shown in Figure 4 and tighten the camshaft sprocket to 58 ft/lbs. 
5.	Install timing chain with silver plates to matching RH camshaft sprocket timing marks as in Figure 5.
6.	Install the 1st chain around valley idler sprocket, then over the LH side idler sprocket, aligning the silver links of 1st chain to idler sprocket timing marks in Figure 6.
7.	Install 1st chain matching with gold or yellow plates with crankshaft sprocket Figure 7.

8.	Caution: turning crankshaft while the timing chain is off will bend valves.

9.	Align timing marks on LH #2 idler and crankshaft sprocket as in Figure 8.
10.	Align camshaft dowel pins with match marks on the cylinder head in Figure 9.
11.	Install by aligning match marks (2) on yellow plate of LH 2nd timing chain and idler sprocket #2 as in Figure #10.
12.	Hold the camshaft using a spanner wrench see figure #11 on the hexagonal section of the camshaft to hold it stationary. Install sprockets to intake and exhaust camshafts by aligning silver plate of LH #2 timing chain, match marks on intake sprocket and exhausts respectively in Figure #11. Torque the sprockets to 58 ft/lbs.

13.	Caution: Do not turn camshafts more than necessary. If turned excessively, valve and piston may get damaged.

14.	Install timing #3 chain tensioner compressed and plunger retained with a pin in Figure 12.
15.	Tighten timing chain tensioner bolt c 18 ft/lbs, bolt d 32.5 ft/lbs tightening order 1, 2 & 3 see Figure 13.
16.	Assembled front view as shown in Figure #14.

                                                                             The AERA Technical Committee

                          Intake Manifold Modification Improves Cooling On
                                                    Suzuki 1.3L Engines

The AERA Technical Committee has recently become aware of a repair procedure on 1985-92 Suzuki 1.3L intake manifolds to improve engine cooling.  Beginning in June 1992, a revised intake manifold went into production to supplement engine cooling.  The change, effective VIN Code #JS4JC31C-N4102470 also involves a revised thermostat, which is not interchangeable with the older design.

It is possible to modify the older (1985-92) intake manifolds to take advantage of the revised thermostat and provide more effective engine cooling.  The modification involves enlarging the water port opening to 1.890 and the thermostat mounting counterbore to 2.224.  Refer to the illustrations below to
assist in the machining of the intake manifold.

The revised thermostat now incorporates a rubber O ring on the outside diameter to provide a more effective seal.  There are currently two thermostats available, Part #17670-56B00 for 180 degree Fahrenheit opening, and Part #17670-56B10 for 190 degree opening.

                                                                       The AERA Technical Committee

                                                    Front Engine Oil Leak On
                                             1999-2003 Suzuki 2.5 & 2.7L Engines

The AERA Technical Committee offers the following information regarding a front engine oil leak on 1999-2003 Suzuki 2.5 & 2.7L engines. If oil is observed leaking from the left front of the engine resealing the timing cover may resolve those types of customer complaints.

To do so, two types of sealers are recommended from Suzuki to use at specific locations of the front cover. Refer to the illustrations below and follow the steps indicating the locations to use sealers ?A" or ?B". 

1.	Clean sealing surface on timing chain cover, crankcase, cylinder block and cylinder heads. Remove oil, old sealant, and dust from sealing surface. 
2.	Apply sealant A: Suzuki Bond 1207F (# 99000-31250) to timing chain cover sealing surface area as shown in the Figure 1. Ensure proper sealant bead. Do not over apply.


3.	Apply sealant B: Suzuki Bond 1207B (# 99104-31140) to the mating surfaces of the cylinder heads and cylinder block as shown in Figure 2. 
Figure 2

4.	Use a plastic scraper as a jig to force the sealer into the air gap formed by the cylinder head, block and head gasket as shown in call-out A. There are four areas B where this must be performed.
5.	NOTE: Failure to perform the step 4 will result in oil weepage/seepage that will migrate down the front side of the engine block. This may appear and be misdiagnosed as a crankshaft oil seal leak.

                                                             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