Engine - Rattle Noise on Start Up
303-30DATE
12/98
V8 XJ Series/XK8
MODEL
1997-99 MY XK8 Range
1998-99 MY V8 XJ Series
VIN
Refer to engine
no. in text
Noise During Start Up - Install Revised Timing Chain Tensioners
Issue:
Some vehicles within the above VIN range may experience a rattling noise when the engine is started. This noise may be caused by the secondary timing chain tensioners. 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. Introductory VINs are not yet available. In case of a customer complaint, the revised tensioners may be installed on earlier V8 engines.
Action:
In case of a customer complaint of start up noise, determine if the noise is caused by the secondary timing chain tensioners. If the secondary timing chain tensioners are the cause of the noise, they should be replaced by the revised tensioners (Illustration 1).
^ The revised tensioner has a coil spring that presses on the piston head to provide a damping effect.
^ To simplify the installation of the tensioner on the engine, a clip (shown in Illustration 2) is provided to hold the piston in a partly compressed position during assembly.
^ When the piston and spring assembly is compressed to approximately half of its travel, the pin end of the clip is inserted into the hole in the tensioner body, in front of the piston head/slipper, with the finger ring of the clip positioned at the rear of the head, (as shown in Illustration 1).
^ Installation of the tensioners is covered in JTIS 5, section 303-01, Basic Engine, Removal and Installation, Timing Chain Tensioner (Secondary) - A-Bank (12.65.63) or Timing Chain Tensioner (Secondary;) - B-Bank (12.65.64).
^ The method of removing and reinstalling the secondary timing chain tensioners has been simplified by the use of a ball-end drive bit as described in Technical Bulletin 303-28, dated 8/98.
^ The installation of the revised tensioner, (1, Illustration 3), is the same as the original style tensioner except that it must be installed in the compressed condition (retained by the clip).
^ The retaining bolts should be tightened to the recommended torque setting of 10-14 Nm (7.4 - 10.3 lb. ft, 88.5 - 123.9 lb. in.), (2, Illustration 3), before the clip (3, Illustration 3), is removed to release the piston and tension the secondary chain.
Note:
After installing a revised tensioner and removing the clip, save the clip as a service tool to assist in any future removal and reinstallation. To avoid the loss of the clip inside the timing cover, attach a length of string to assist retrieval.
Parts Information:
Warranty Information: