The Land Rover Freelander have had serious problems of head
gasket malfunction which will lead to engine failure. First signs of a problem include coolant
leak, overheating, and engine performance problems. This will usually lead to the engine failure
which characterizes the 2002- 2005, model years of the Land Rover Freelander
manufactured with the KV6 2.5 liter aluminum V6 engine. Owners may be entitled to compensation. Here is a more technical overview.
Design and Components
of the Vehicle
This engine is referred to as an aluminum V6 engine because it is
manufactured using an aluminum cylinder block along with aluminum cylinder
heads. Many internal components are however made of steel and iron. Most
automotive manufacturers today offer aluminum V6 engines that would fall under
this description. The KV6 engine shares several technical features with other
manufacturer’s aluminum V6 engines of the 2002-2003 period such as double
overhead camshafts, four valves per cylinder design cylinder heads, and
variable intake manifold tuning.
One distinct design feature of the KV6 engine that makes it
different from common aluminum V6 engines is the use of slip fit steel cylinder
sleeves (or liners) in it's construction. All of the aluminum V6 engines that I
have been exposed to (from Chrysler, Ford, GM, Honda, and others) use a press
fit cast iron cylinder sleeve. Typically, engines using the cast iron cylinder
sleeve design have demonstrated virtually no issues related to the sleeves or
their integrity as assembled in the aluminum cylinder block. This is not the
case with the KV6 engine design. I discovered an alarming number of reports
describing failures (head gaskets and engine seizures) related to the sleeves
of the KV6 engine.
Typically when aluminum cylinder block-iron sleeve engines
are manufactured, the cylinder bores of the aluminum block are slightly smaller
than the outside diameter of the cast iron sleeves before assembly at room
temperature. This difference in sizes is referred to as interference and won’t
allow assembly while the block and sleeves are both at room temperature. The
block is heated to over 600 degrees F to allow it to fully expand before the
cool or room temperature sleeves are pressed (forced) into place within the
block and then allowed to cool at a controlled rate as an assembly. The amount
of force used to press the sleeves into the block varies with designs and can
be from a few hundred pounds to a few thousand pounds. This process assures a
permanent, unchanging fitment of the sleeves to the cylinder block.
With the Freelander engine the sleeves are simply slipped
into place as the engine is assembled. The sleeves of the Freelander engine
have a shoulder machined into them about midway down the outside of the sleeves
which rests on a machined land within the cylinder bores of the engine block as
the engine is assembled. The sleeves essentially have two outside diameters
with the lower end being smaller than the upper. It would be critical that
these machined surfaces be of high quality and precision as once assembled, the
contact area of the two surfaces would have to provide a seal between the
coolant jacket of the cylinder block and the engine crankcase where the engine
oil is collected and stored in the engine oil pan. The Freelander engine design
relies on the clamping force of the cylinder head and gasket of the assembled
engine to maintain a tension against the sleeves from the top to ensure a seal
at the two machined surfaces described. The cylinder head gaskets are
manufactured with a metal compression seal ring that is mated to the tops of
the sleeves and these compression seal rings have a designed, calculated
"crush" that upon assembly, ensure a permanent seal between the high
temperature and pressure combustion gases, and the separate coolant and oil
circulation passages of the assembled cylinder block and heads. It is important
to note that the tops of the sleeves of the Freelander engine are designed to
be flush with the head gasket surface of the cylinder block when assembled so
that the head gasket will perform it's purpose of sealing effectively.
Incidence of Engine
Failure
Many head gasket failures have been reported on the
Freelander engine on the vehicle and it has been determined that this has been
commonly caused by a condition where a cylinder sleeve (or sleeves) has
"dropped" in the engine block (meaning that the top of the sleeve has
moved below flush with the head gasket surface of the block). The condition
occurred often enough that Land Rover issued a bulletin (Technical Bulletin #0036,
dated June 16, 2004) for it's dealership technicians to provide a process for
inspection and evaluation when a vehicle came in for repair. Though this
bulletin also addresses an overheat condition diagnosis and repair, engine
overheating often accompanies head gasket failure. The head gasket would have
failed primarily because the tension of the crushed compression seal ring would
be compromised as the sleeve moved lower into the block and away from the
cylinder head, ultimately allowing coolant intrusion into the combustion
chamber and combustion gases into the cooling system. This loss of tension
against a cylinder sleeve would also compromise the sealing effectiveness of
the aforementioned machined surfaces of the sleeve and cylinder block and allow
coolant intrusion into the crankcase and engine oil, and thus causing
catastrophic engine failure as the lubricating qualities of the engine oil are
severely diminished when antifreeze coolant is mixed with it.
Mechanism and dangers
of engine failure
This would explain another common concern with the
Freelander engine where the engines have seized (locked up), often times while
driving. The reason that the sleeves drop in the block seems to be apparent and
easy to understand. There are two basic principles at work in this issue.
First, there is a significant difference in the thermal properties of steel and
aluminum, and second, the steel cylinder sleeves are substantially harder than
the alloy aluminum cylinder block they are fitted to.
Aluminum expands and contracts at a greater
rate and degree than steel when heated and cooled.
In the normal life of an automotive engine
there are an incredible number of these heating and cooling cycles- ie: cold
start up to normal operating temperature and then cool down when shut off,
occasional high work loads from trailer towing, climbing long grades in extreme
weather conditions, etc. After enough of these cycles, the precision machined
surfaces of the relatively soft aluminum cylinder block that relate to the fitment
of the much harder steel sleeve would understandably be compromised as the
aluminum is moving quicker and more than the steel in the process of thermal
expansion and contraction. Add to this the fact that as the engine is running,
pistons are moving up and down within the sleeves at a high rate of speed with
some friction (normal-from the way that they are designed to fit within the
sleeve), pushing up on the sleeve as the piston rises and then pulling down on
the sleeve as the piston descends. This can effectively cause the hard steel
sleeve to "hammer" against the machined surfaces within the bores of
the softer aluminum cylinder block. Theses actions could be expected to cause
the machined surfaces within the block to deteriorate and/or damaged to a point
of failure.
This helps to explain why
the sleeves drop in the cylinder block, causing head gasket failure and even
catastrophic engine failure.
If this
occurs in traffic, mechanical features such power braking will not
function.
Stopping and maneuvering the
vehicle particularly in traffic become a serious problem, and the condition
poses dangers to the driver, occupants, and other vehicles.
Law Office of Howard A.
Gutman
230 Route 206, Suite 307
Flanders, New Jersey 07836
(973) 598-1980 (tel),
(973) 531-4110 (fax)
New York Office
315 Madison Avenue, Suite
901
New York, New York 10165 Free consultation on Land Rover Defect Claims
howardgutman@aol.com
