Discovery I (LJ) V8-3.9L (1994)
Valve Guide: Technical Service Bulletins
Engine - Valve Guide Cleaning
No: 12/01/00/NAS
Ref:
Issue: 1
Date: 09/29/00
Use of Land Rover Tools for Valve Guide Cleaning
AFFECTED VEHICLE RANGE:
Range Rover (LH & LP) All
Discovery (LJ & LT) All
Defender (LD) All
SITUATION:
CYLINDER HEAD OVERHAUL DIFFICULTIES
Cylinder head overhauls, particularly in cases of exhaust valve sticking, have previously been carried out using a single Valve Guide Cleaner
(LRA-12-003) as directed in the Land Rover V8 Engine Overhaul Manual. The use of the single cleaner has in some cases been difficult. Also repeat
valve stick failures due to further carbon build-up over time have occurred.
RESOLUTION:
STEPPED SET OF VALVE GUIDE CLEANER TOOLS
Land Rover has now introduced a stepped set of three cleaners, designed to increase the exhaust valve guide internal diameter by 10 microns (0.0004"),
and to ensure that all carbon and valve guide material can be removed as easily as possible.
The process set out in this TIB should always be used where exhaust valve stick is suspected or confirmed to have occurred. This process replaces the
exhaust valve guide process described in the Engine Overhaul Manual and should be used for all valve replacement and cylinder head overhaul
processes.
TOOL INFORMATION
WARRANTY CLAIMS
Normal warranty policy and procedures apply.
REPAIR PROCEDURE
NOTE: