Whenever you talk high-kay 4WDs, the fi rst thing that comes to mind
is engine issues. If you haven’t experienced major fi nancial trauma
through blown head gaskets, failed fuel pumps, leaky turbos and the
like, then chances are you know someone who has! Complicating
this issue of longevity with high-kay motors is the fact that modern
motors are, well – way more complicated. We sat down with two of
the industry’s leading diesel experts to talk all things engines.ARE COMMON-RAIL MOTORS
REALLY MORE COMPLICATED
THAN OLD DIESELS?
Open up the engine bay of any modern 4WD, and most of us would
be hard-pressed to name half the components. It’s a far cry from
the old TD42s and 1HZs that have been powering our rigs for
decades. We asked Mitch Legdin from MTQ Engine Services what he
thought about the question.
“Why the common-rail engine is perceived as complicated, could
come via the myriad of ECU’s, sensors, actuators, connectors and
wires which monitor and control every aspect of the engine
operation and performance. History has shown that the possibilities
for problems in these areas are endless, especially in the extreme
environments that some vehicles are subjected. In most applications
the basic engine design is still the same as it has been for many
years, with Crankshaft, Pistons, Camshafts and Valves. The old-tech
engines were either indirect injection via a pre-combustion chamber
or direct injection types and may or may not be Turbocharged. Most
if not all Common-rail engines have direct injection and
turbochargers. The drive for better performance, reduced fuel
consumption and reduced emissions has seen the transition from
full mechanical fuel systems to the common-rail systems. The fuel
systems of the common-rail engine is arguably less complicated as
it has less moving parts, but the reduced tolerances and stresses to
which the components are exposed, are far more extreme.”ARE MODERN ENGINES
AS TOUGH AS OLD ONES?
How bush-proof are modern engines really, compared to the
older ones? Are they actually as complicated and fragile as
they’re made out to be? To answer this question we spoke with
Andrew Bourne from Diesel Care.
“Modern engines have a lot going for them; performance and fuel
economy beat the oldies hands down,” says Andrew.
“The problem, if there is one, is that they have a lot of systems
that contribute to making them perform so well and effi ciently that
have the potential to give problems. These systems are often
electronic, or are controlled electronically. Sensors measuring all
sorts of conditions must accurately send information to the ECU so
that it can manage the engine correctly. A lot of people would feel
happier doing an epic 4WD trip, like the Canning stock route or the
Madigan Line across the Simpson in an earlier mechanical diesel
engine rather than a modern electronic diesel. Not necessarily
because the old clunkers are more reliable or the new ones less, but
because they feel they’d have a better chance of getting going again
if something goes wrong. Valid point. Modern engines require
specialist knowledge, and equipment such as a scan tool, to have
much chance of fi nding out what’s happening. If you were to consider
all of the major 4WD journeys undertaken in this country over the
past ten years, you would fi nd that the majority of them would have
been done in vehicles with a modern electronic engine, and of those,
the vast majority of them will have completed the journey without a
problem. So, I don’t believe they are that fragile. If I had to pick an
area where electronic engines are vulnerable it would be probably
be water. Electronics and water aren’t normally good companions,
so this is an area where the old bangers might be at an advantage.”ARE 20,000KM FACTORY
SERVICE INTERVALS DOOMING
THE LONGEVITY OF OUR VEHICLES?
These days, the trend amongst manufacturers is to push service
intervals out as long as possible to reduce cost of ownership. It is
indeed a far cry from the 5,000km oil changes we’re all used to.
Andrew from Diesel Care has a strong viewpoint on this.
“It seems the manufacturers continually keep pushing out service
intervals,” Andrew says. “I think their main motivation is that it will
be viewed as lowering the cost of owning the vehicle. To me it’s a
blinkered, short-term view, and I don’t condone it. Modern day diesel
engines are high performance engines. They need to be maintained
well and regularly if they are expected to give service to an old age.
True; synthetic oils have a longer life span than mineral oils, so they
can withstand more use before needing to be changed, however I’ve
seen the inside of plenty of engines and the ones that are still in good
nick after lots of use are the ones that have been running with clean
oil. There are three things that increase engine longevity; clean oil,
clean air, & clean fuel. It’s quite simple.”It’s the biggest question out there. Can a
common-rail motor really go the distance?ENGINE LONGEVITY
WWW.4WDACTION.COM.AU
The mighty V8 turbo-diesel in
the current crop of Cruisers
wasn’t without its share of
issues early onThe 4.5 V8 Cruiser motor
is one of the last bucking the
trend of decreasing engine
capacities. Whether it’s a good
move long-term is yet to be seen