Engine Knock on Jaguar 4.2L Engines

Diagnosis of an engine knocking noise on XJ6 and 12 cylinder Jaguar engines should start by checking the crankshaft pulley for looseness.  A loose pulley bolt could cause such a noise that may decrease as the engine reaches operating temperature.

The crankshaft pulley bolt torque is 150 lbs.ft.  Be sure to lock
down the crankshaft or crankshaft pulley before attempting to
torque the bolt.

                                                                   The AERA Technical Committee

       Suggested Procedure For Removal Of Exhaust Seats On
                  XKE 4.2 Type E Jaguar Engines

Exhaust valve seats have been removed from the subject cylinder
heads successfully by the following procedure:

     1. Drill a 1/8 hole on the top side of the seat to the
     bottom of the seat ledge as close to the recess in the head
     as possible. (See diagram 1)

     2. Use a small chisel to cut through the seat from the ID of
     the seat into the drilled hole removing seat material as
     shown in Fig. 2.

     3. With a hammer and small punch, strike points marked by
     x in Fig. 2.  The seat will break across the drilled part
     of the seat and may be removed with ease.

This engine has an aluminum cylinder head which makes the use of
a conventional puller impractical.

          (insert illustration )        (insert illustration)    
     


                                     The AERA Technical Committee


January 1972 - SPB 5 

##END##

                                            Engine Noise During Start-up On
                                         1997-2000 Jaguar 4.0L V-8 Engines

The AERA Technical committee offers the following information regarding an engine noise during start-up for 1997-2000 Jaguar 4.0L engines. It has been reported that some engines may experience a rattling noise when the engine is started. The secondary timing chain tensioner may be the cause of this noise. Research has shown that a noise can originate at the chain tensioners to cause a resonance in another part of the engine.

A revised, spring assisted, secondary timing chain tensioner has been introduced to eliminate this concern, commencing at engine No. 98102106XX. In case of a customer complaint, the revised tensioners should be installed on earlier built V8 engines.

The installation of the revised tensioner, shown below in Figure 1, is the same as the original style tensioner except that it must be installed in the compressed condition (retained by the clip) as shown in Figure 2. 

The retaining bolts should be tightened to the recommended torque setting 89-124 In/lbs (10-14 Nm) before the clip is removed to release the piston and tension the secondary chain. Note: tying a string to the clip before assembling the tensioner assembly may help recover the clip if it is accidentally dropped. It should also be noted that the tensioner for left and right banks have different part numbers, NCA2017AF for the A bank and NCA2017BE for the B bank.

                                                                    The AERA Technical Committe

                                          Valve Guide Seals On
                               1988-92 3.6L DOHC Jaguar Engines

The AERA Technical Committee advises members of the following information concerning valve stem guide seals on 1988-92 3.5L DOHC engines. Originally, the cylinder head of this engine used a valve stem seal only on the twelve intake valves. Now, since engine number 163522 both intake and exhaust valves use valve seals.

It is Jaguars recommendation that anytime a cylinder head is remanufactured or serviced, valve stem seals be installed on all 24 valves. Jaguar offers a cylinder head gasket kit Part #JLM11088, which contains twenty-four valve stem seals. AERA is unaware of an aftermarket supplier for the valve stem seals and head gasket.

                                                                     The AERA Technical Committee

                                           Cylinder Head Surface Erosion 
                            On 1983-94 Jaguar 3.6, 4.0 & 4.2L XJ6 Engines

The AERA Technical Committee offers the following information on cylinder head surface erosion on 1983-94 Jaguar 3.6, 4.0 & 4.2L XJ6 engines. Upon removing the cylinder, cylinder head gasket material may be found 
burned, or erosion may exist on the inlet side of the head gasket surface. If either condition is found, the head must be checked to determine the correct repair.

Checking the cylinder head surface for warpage should be done first. Warpage of the cylinder head should not be more than .003 (.076 mm). Head thickness must also be measured and observed as listed in the chart below. Minimum 
parallelism between faces should not exceed .002. Desired surface finish must not exceed 1.6 Microns or 62.992 Ra (1.6 / .0254 = 62.992 Ra).

     Engine                  Min. Head Thickness     
     3.6 Liter               5.101 (129.565 mm) 
     4.0 Liter               5.108 (129.743 mm)
     4.2 Liter               4.855 (123.317 mm)

Checking for excessive erosion damage should also be done. For reference, fabricate a template that corresponds with the affected area on the head and block as shown in Figure 1. Those areas include the cooling holes of the cylinder block and the adjacent cylinder head bolt holes. Position the template on the head by aligning the cylinder head bolt holes. If erosion on the deck of the cylinder head is within the cutouts of the template, see Figure 2, the 
cylinder head is acceptable and can be reinstalled. If the erosion overlaps the cutouts as shown in Figure 2, or if there is excessive warpage, the head requires machining. Be sure not to exceed the minimum head thickness listed above.

If erosion still exists after machining, use the template again to see if the areas are beyond the limitations. Some AERA members have indicated welding heads with excessive erosion as a successful repair.
 
                                                                       The AERA Technical Committee

                                       Camshaft Identification & Location For
                                         1988-92 Jaguar 3.6L DOHC Engines

The AERA Technical Committee offers the following information regarding camshaft identification and location on 1988-92 Jaguar 3.6L DOHC engines. This engine design incorporates 24 valves and uses two unique camshafts to actuate the valve train. Those camshafts may appear to be identical at first glance, as there are many similarities, but their location in the head is specific.

Stamped numbers are used to identify each camshaft: the intake cam is #C37583 and the exhaust cam is  #C37582. If those numbers are unreadable, an alternative method of identifying may be used for cam installation.

Each cam has a timing V notch cut into the cam thrust ring; it should be at the 12 o?clock position during cam timing. When correctly installed in the cylinder head, the first cam lobe after the cam thrust ring of each cam will face each other. Those first lobes will also be pointed toward the spark plug threaded hole.  

                                                                     The AERA Technical Committee

                                          Bedplate Installation Caution For
                                         1997-2000 Jaguar 4.0L V8 Engines

The AERA Technical Committee offers the following information regarding a main bearing bedplate installation caution for 1997-2000 Jaguar 4.0L V8 engines. This engine uses three different bolt thread sizes used. If the improper torque is used on certain bolts, lower end failure of the engine could result. 

Jaguar uses 34 bolts to hold the bedplate onto the cylinder block and there are 4 different bolts used. The bedplate is to be installed after piston and connecting rod assemblies are installed and all bolts MUST BE replaced after each use. To install the bedplate correctly, follow the procedure listed below and refer to Figure 1 below for the proper bolt locations.

        Step 1          Install ?P" bolts and torque to 10-12 ft/lbs
        Step 2          Install ?F" bolts and torque to 18-19 ft/lbs
        Step 3          Install ?M" bolts and torque to 18-19 ft/lbs
        Step 4          Install ?S" bolts and torque to 10-12 ft/lbs
        Step 5-6      Torque ?M" bolts to 25-27 ft/lbs + 135°
        Step 7-8      Torque ?S" bolts to 14-15 ft/lbs + 150°
        Step 9-10    Torque ?P" bolts to 14-15 ft/lbs + 90°
        Step 11-12  Torque ?F" bolts to 14-15 ft/lbs + 150°

Center-punch bolts after torque sequence is complete.

                                                                          The AERA Technical Committee

                                Jaguar Upgrade On Valve Retainer, Keepers, Seals 
                                                And Spring Seat For 3.8L Engines

The AERA Technical Committee offers the following information on Jaguar upgrade on valve retainers, keepers and spring seats for 3.8L engines.

Jaguar has used two different style valve retainer, keeper, seals and spring seat setups. Intermixing the different designs may cause component damage, don?t mix them. Only one of the setups used intake seals and the other did not. Early engines built up to around 1968 did not use intake valve stem seals. It is, however, recommended to install valve stem seals on heads that didn?t use them. To do so, the later style retainers, keepers and spring seats must be used to provide valve seal clearance. See Figure 1 below.

Note: Most shops install the larger diameter XJ intake valves during cylinder head rebuilding which will improve performance slightly. It is also suggested to install tappet sleeve hold-downs on the exhaust side since they have a tendency to work loose.

Figure 1
The AERA Technical Committee

                           Valve Crosshead To Rocker Lever Clearance On
                              NH, NT & V-1710 Series Cummins Engines

Valve crosshead nose to rocker lever clearance on the subject engines must be checked during engine rebuild and at any time valve crossheads are replaced on engines using crossheads No. 123416 & 3000326. A minimum of .020 (.51 mm) clearance must be present as illustrated in Fig. 1, on the cylinder being checked with valves completely closed and crosshead in the upmost position. After installing rocker lever assemblies, check crosshead to rocker lever clearance as follows:

1. Turn crankshaft slowly in direction of rotation until the valves are closed on the cylinder being checked. With rocker lever held firmly against the stellite pad of the crosshead, a .020 (.51 mm) wire type feeler gauge must pass between the crosshead nose and the lower beam section of the rocker lever.

2. If the feeler gauge does not pass through:

a. Remove the rocker lever and/or crosshead and grind the nose of the crosshead or 	rocker lever beam in the area circled in Fig. 1 until enough clearance is obtained.

b. If the rocker is ground, grinding should cover the complete area illustrated in Fig. 2 in a continuous arc. Do NOT grind just the contact area.

Caution: A sharp depression in this area will cause a stress riser and eventual failure of the lever. Grind only enough material to achieve the required clearance. If grinding enters the oil passage, the rocker lever must be junked.

c. Grind sharp edges smooth.




                                                                   The AERA Technical Committee