Engine - Overheating Condition
No: 12/02/06/NASFGN 303 - Engine System
Ref: 10/01 105/NAS
Issue: 1
Date: 25 Sept 2006
KV6 Engine Overheating - Engine Repair Diagnosis -
Head Gasket Replacement
AFFECTED VEHICLE RANGE:
Freelander (LN) (KV6 engine)
VIN: 2A353298 onwards
SITUATION:
KV6 ENGINE OVERHEATING RESULTING IN HEAD GASKET FAILURE AND REPLACEMENT
The KV6 engine may overheat as a result of any condition causing coolant loss or a customer failure to maintain proper coolant levels. Engine overheating can lead to head gasket failure.
A coolant leak from any part of the engine or cooling system may be the cause.
RESOLUTION:
DIAGNOSE ENGINE FOR REPAIRS AND HEAD GASKET REPLACEMENT
Should a KV6 engine require head gasket replacement, refer to the Repair Procedure detailed in this bulletin to carry out engine component checks and ensure that the engine is rebuilt correctly.
PARTS:
Diagnostic and repair procedure information.
SPECIAL TOOLS:
LRT-12-144........Cylinder liner retainer
Locally sourced solvent based Gasket Stripper or general purpose cleaner.
WARRANTY CLAIMS:
No warranty required. Diagnostic and repair procedure information only.
Normal warranty policy and procedures apply.
REPAIR PROCEDURE
IDENTIFY ENGINE COMPONENTS REQUIRING REPAIR OR REPLACEMENT
1. Verify that the engine has been severely overheated.
2. Check engine oil for contamination.
3. If engine coolant is present in the engine oil, drain and refill with new engine oil.
NOTE:
If an obvious lower engine knock is heard, the engine will require replacement.
4. Start the engine and listen for any signs of abnormal engine noise as a result of excessive overheating.
5. If the engine has an obvious lower engine knock, the engine should be replaced.
NOTE:
Overheating may have damaged a cylinder head. On confirmation that a cylinder head gasket is leaking, the checks that follow must be carried out to determine if the cylinder heads are serviceable.
Global Technical Reference (GTR) lookup sequence is as follows:
GTR Home > NAS > Service Information/ LN - Freelander/2002 > Workshop Manuals > Service Procedures > Bookmark "12-3 - Engine - K Series KV6" link "12.29.02 Cylinder head gasket - LH" and "12.29.03 Cylinder head gasket - RH"
6. If no abnormal engine noise is heard, but cylinder head gasket leaks are detected, refer to GTR section 12-3 operations 12.29.02 and 12.29.03 and remove the LH and RH cylinder heads.
INSPECT ENGINE BLOCK ASSEMBLY FOR DAMAGE
CAUTION:
The cylinder liners must not be rotated or lifted. Ensure liner clamps are in position before rotating engine with the cylinder head removed.
NOTE:
The engine block assembly must be examined for damage prior to re-installation of the cylinder head. A complete overhaul of the engine block assembly is not required but the following checks must be completed.
The cylinder liners of the KV6 engine are a "slip install" into the engine block. Free rotation of the liners is normal and does not indicate engine block damage. Liner clamps must be used to avoid liner movement. For additional information, refer to GTR Section 12-3.
1. Install cylinder liner retainers LRT-12-144.
2. Check for a slight rocking movement of the pistons in the bores. (Figure 1)
NOTE:
The pistons should move slightly in the bores. If the pistons cannot move then the piston rings may be seized. If any piston ring has seized, the engine must be replaced.
3. If any piston cannot move, replace the engine.
VERIFY CYLINDER LINER POSITION
CAUTION:
Do not use a metal scraper or Scotch Brite(TM) to clean the cylinder block surface, as these can leave abrasive debris.
NOTE:
Cylinder liner position is the distance that the cylinder liner protrudes above the surface of the engine block. Liners can be 0.025 mm (0.001 in) -0.15 mm (0.004 in) above the surface of the engine block. If the liners are below this condition, the engine should be replaced.
1. Clean the cylinder block surface using a soft cloth or paper towel.
2. Ensure the cylinder block surface is free from any damage.
NOTE:
Checks must be carried out on both the inlet and exhaust manifold sides of the cylinder liner.
3. Place a suitable straight edge across the cylinder liner.
4. Using a feeler gauge, measure the distance between the engine block surface and the straight edge. (Figure 2)
5. Check the condition of the cylinder bores for scuffing or scoring as evidence of piston partial seizure.
6. If there is any sign of bore damage other than normal wear, the engine must be replaced.
INSPECT CYLINDER HEADS FOR DAMAGE
NOTE:
The cylinder heads must be examined for damage prior to re-installation. For further details of cylinder head examination refer to the cylinder head overhaul section in the Freelander Workshop Manual. For additional information, refer to GTR section 12-3.
A complete overhaul of the cylinder head is not required but the checks that follow must be completed.
CAUTION:
Do not use a metal scraper or Scotch Brite(TM), as this can leave abrasive debris.
1. Using a suitable solvent, clean each cylinder head surface using a soft cloth or paper towel.
NOTE:
Pitting, porosity or pinholes to a cylinder head surface may cause the gasket to fail again.
2. Paying particular attention to the gasket mating surface of the cylinder head, check each cylinder head for damage.
3. If there is pitting or porosity, the cylinder head must be replaced.
NOTE:
Cylinder head surface longitudinal flatness must be within 0.08 mm (0.003 in) and lateral flatness within 0.025 mm (0.001 in).
4. Using a suitable straight edge and a feeler gauge, check each cylinder head surface for warping across the center and from corner to corner.
NOTE:
Indentation in the cylinder head does not indicate that the engine block is unserviceable.
5. Paying particular attention to the exhaust side of the cylinder head, where the indentations are most likely to be found, visually inspect each cylinder head for any sign of an indentation made by the fire ring of the head gasket.
6. If there is evidence of indentation, the cylinder head must be replaced.
NOTE:
Scratches or handling damage up to 0.2 mm (0.008 in) deep may be repaired by having the cylinder head re-surfaced. If the cylinder head has been re-surfaced, the height of the cylinder head must be greater than 118.95 mm (4.683 in). (Figure 3)
7. If the cylinder head surface has any scratches or handling damage less than 0.2 mm (0.008 in) deep, re-surface the cylinder head.
8. If the cylinder head has been re-surfaced, verify that the height of the cylinder head is greater than 118.95 mm (4.683 in). (Figure 3)
INSTALL CYLINDER HEADS
NOTE:
An existing cylinder head may only be installed if that cylinder head and the engine block assembly have complied with all checks and specifications detailed in this bulletin.
CAUTION:
When installing the cylinder heads, the correct cylinder head bolt torque and tightening sequence detailed in GTR section 12-3 operations 12.29.02 and 12.29.03 must be used.
NOTE:
If the engine oil was contaminated with coolant, the engine must be flushed using an approved engine flush product before refilling with correct grade oil.
NOTE:
If the coolant was contaminated with engine oil ensure the following:
^ Any excessively contaminated cooling system component is replaced as necessary, e.g. coolant hoses, radiator or the heater matrix.
^ The coolant system is thoroughly flushed, as many times as required, to ensure the system is clear of contamination.
NOTE:
The correct specification of anti-freeze (LRN2279 Texaco XLC) must be used in the cooling system. For further information, refer to the Maintenance Fluid Specifications Technical Bulletin 10/01/05/NAS, dated 28-Sep-2005.
NOTE:
The cooling system must be correctly bled using Vacuum Fill equipment if available.
CAUTION:
A final cooling system pressure test must be completed to confirm no loss of pressure. If any pressure loss is detected further investigation must be carried out to establish the cause or the pressure loss (secure hose connections etc) and the issue(s) rectified as necessary to meet coolant system pressure test specifications.
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