This part of site is an attempt to organize and add to the web resources for the Rover SD1
to form a cohesive and easily usable guide for those of us without easy access to
expert repair and/or advice. It is not offered in any way as a definitive source
and we take no responsibility for any errors that may exist.
Webmaster Rene Winters
Injectors Removal and Testing|
However, if only the spray patterns are incorrect, it is permissible to dismantle the injector to
clean it. To do this separate the two housings, noting the position of internal components.
Now we will look at the injectors. These are removed with the aid of the slide hammer 18G 284 and its
adaptor 18G 284-10.
Once removed from the engine, the injectors can be tested on a pressure tester like the one shown here.
Begin with the dry seat test. Slowly operate the tester to 116 atmospheres (1650 lbf/ in2). There should be
no leakage at this pressure. If there is then it is likely that oil dilution will occur.
Next check that injection only occurs above a pressure of 148 atmospheres (2,000 Ibf in2).
Finally check the spray pattern. This should be an even cone with a central core and no evidence of
dribbling. If the injector does not meet the pressure tests, replace it.
Try not to touch the injection needle as the moisture in your skin may induce corrosion. If you must touch
it, then ensure that your hands are coated with test fluid. Clean the nozzle needle
with a chamois leather.
Then clean the nozzle spray orifice with a piece of fine steel wire.
Once you have cleaned the components then reassemble the injector and retest it.
The increased pressure of air in the inlet system, increases the volumetric efficiency of the engine.
More air is made available for combustion enabling more fuel to be burnt, with a resultant increase in power
If we were to take a look inside a turbocharger when running, we would find that the exhaust gases pass
through a turbine, A, commonly known as the hot wheel, causing it to rotate. The turbine is mounted on a
shaft at the other end of which is the compressor or cold wheel, B, which rotates at the same speed as
the turbine, pumping air into the inlet manifold.
One problem does exist, however. As the engine accelerates, the increased volume of exhaust accelerates
the turbocharger proportionally more than the increase in engine speed. If left uncontrolled,
the engine may self-excite to the point of destruction.
To prevent this, we fit a valve known as the wastegate between the exhaust manifold and the exhaust pipe.
As the designed inlet manifold pressure is reached, the wastegate is opened, permitting a proportion of the
exhaust to by pass the turbine restricting the speed of the turbocharger.
The operation of the wastegate is controlled by the boost pressure operating on a spring loaded diaphragm
connected to the valve. As the boost pressure reaches the normal operating range of 0.83 - 0.93 kgf/cm2
(12 - 13 Ibf/in2) the valve opens.
The turbocharger requires little servicing. At 60,000 miles (100,000 km) and every 24,000 miles
(40,000 km) thereafter the axial clearance should be checked using special tool 18G 191 - 3 and a dial
Use the same tools to check the radial clearances. If either clearance exceeds the permitted tolerances,
the turbocharger should be replaced.
At the same time, check the operation of the wastegate by connecting gauge 18G 1116 into the tapping in
the inlet manifold. Slowly accelerate the engine and, at the same time, observe the boost pressure.
It should increase as the engine speed increases until the wastegate opens, when the boost pressure should
Next let us consider some of the faults you may have to diagnose on a turbo diesel engine. Such faults will
present themselves in one of 4 ways; excessive smoke, loss of power, unusual sounds or vibrations and oil
leakage on the compressor side.
Always consider the turbocharger last when diagnosing such a fault. Look at the other items first.
For instance, excessive smoke or loss of power may be caused by a blocked air cleaner, restricted intake pipe
or faulty fuel system.
So your first checks would include inspection of the intake system and checking the fuel system.
Unusual noises can be traced using a screwdriver as a stethoscope. If they come from the turbocharger then it
is likely that a failure of the oil supply to the bearings has damaged them.
One fault you may consider difficult to diagnose is a leakage of oil from the compressor side.
If we were to look inside the turbocharger, we can see that the seal, in white, operates in an environment
with oil pressure on one side and boost air pressure on the other. As the engine speed increases, so do the
two pressures. If a restriction occurred in the inlet side then the pressure difference between the oil
pressure and boost would be increased. As a result oil may leak past the seal. So before replacing the
turbocharger in this case, you should check and rectify the low boost pressure.
The Repair Operation Manual Supplement contains a Fault Finding Procedure to assist you in locating