Injector O-Rings Replacement

If your vehicle is suffering from engine oil dilution, i.e. the engine oil is appearing to get rather thin and smelling of diesel, then a cause may be the deterioration of the injector o-ring seals.

The photograph to the left shows a new o-ring fitted. Be careful not to fit the o-ring to the next lower groove by mistake as this will not allow the injector to seal and engine oil dilution will continue.

The o-rings can be readily purchased from independent suppliers at online shops and also eBay.

It is very advisable that the copper washers are also changed at this time too, as failing to do so may caused blow-by of cylinder gases through the injector tube, resulting in poor cylinder compression and running.

Some people chose to place the new copper washer on the end of the injector with the tiniest amount of automotive grease before re-inserting the injector into the tube. Other people drop the new copper washer into the tube first, then lower the injector into the copper washer once centralised with a screwdriver.

If you choose to drop the copper washer into the tube first, be careful that any resistance felt in the final part of injector insertion is not due to a misaligned copper washer, rather than the resistance of the o-ring sealing and tube. Do not use excessive force as this will damage the copper washer when it is struck by the injector point.

You may also wish to change the rocker cover gasket whilst carrying out this job. However, bear in mind that there are two types of pattern and so you may have to seek advise from your supplier to ensure you obtain the correct part. Basically, one pattern has an additional little piece of material at the front part of the gasket.

NB. Check the condition of the cylinder head injector tubes as they have been known to crack, particularly at cylinder number 2.

Use Diagnostic Code Readers

For anyone who wishes to test the engine management on your Landrover TD5, be aware that hand held devices for sale will not work on diesel engine vehicles first used before 2004 as those vehicles are not OBD compliant.


NOTE: Scanners will be advertised as being compatible with 1996 or newer cars and light trucks that are OBDII complient. However, for diesel vehicles in the UK this standard was not introduced until 2004.

The port to plug in such devices can be found in the driver's foot well, to the left hand side underneath the large opening panel.

TD5 fuel pump testing and replacement

Should your vehicle engine suddenly stop operating, one cause may be the fuel pump. It is quite common for the fuel pump to become noisy during it's operation, and can be noticed during the initial switching on of the ignition. For the first 30 seconds the fuel pump will operate whilst maximum fuel pressure is achieved. It is now before the engine is started you will hear the fuel pump running and any strange noises.

Where is the fuel pump located? The fuel pump is mounted within the fuel tank. Access to the fuel pump can be made through the boot floor of the vehicle. In the case of a 5 seater vehicle, the carpet can be carefully lifted up sufficiently without having to remove any interior trim pieces.

Next remove the 6 posi-drive screws from around the circumference of the cover fitted to the boot floor. Lift the cover to expose the fuel pump fuel and electrical connections. The cover should lift away very easily, as an original part there should be no sealant.

Test the electrical connections to the fuel pump to determine if there is an electrical supply to the pump. This will help to establish if the pump is defective. Squeeze the ends of the electrical plug and gently pull upwards to remove. You will see 4 wires; two thick wires, white and black and also 2 thin wires. The thick wires are supply wires to power the fuel pump. The thinner wires are for the sender unit, controlling power to the fuel gauge on the dashboard. At this stage you will need a basic multi-meter or test lamp. Turn on the vehicle ignition and place the test meter / test lamp probes across the two thick wires at the plug. the ignition must NOT be left on for longer than 30 seconds when conducting this test, as after this the current will turn off and will require the ignition to be switched off and on again. If you see a reading of around 11.5 to 12 volts, then subject to the plug being a good fit with no corrosion at the terminals there will be a supply to the fuel pump and it is likely the fuel pump is defective.

Obtaining a new fuel pump from competitive market places such as eBay is a good idea, as dealers tend to charge inflated prices. The photograph here shows a fuel pump obtained from eBay for £95 delivered compared to a quote of £219 from a dealer (August 2011).

If you shop around you can quite easily obtain an aftermarket pattern fuel pump for less than half the listed retail price at the main dealers. The original part is prone to failure anyway so there is really nothing to lose by shopping around in this case.

The item purchased for this repair came with a new rubber seal. If you wish you can also buy a new gasket for the cushioned floor cover, but this will probably not be necessary if the cover gasket comes away in one piece.

Before you start to replace the fuel pump you should ensure that 'wet' down the exposed part of the pump in the boot floor and clear away any dirt and debris that might otherwise fall into the clean fuel in the tank.

To remove each of the fuel pipes, squeeze the two side clips gently and withdraw each plastic pipe in turn. These pipes are colour coded and must go back in the same positions as removed.

Remove the ring by tapping it gently with a blunt tool in an anti-clockwise direction. The ring may only turn for about 3/4 of one full rotation, before it can be lifted clear.

The fuel pump is spring loaded to the tank base, so after a little gentle lifting it will come free of the tank. Carefully withdraw it taking into account the sender unit operating arm and float. Be ready to catch any spilled fuel that is contained within the pump unit.

Next, connect up the new fuel pump wiring plug. The photograph top the left shows this being done before the old pump was removed, just to be sure the new pump operated as it should. Turn on the ignition switch very briefly and you should hear the fuel pump running. Do not leave the pump running dry for more than a few seconds, as it is not necessary and prolonged dry running may damage the fuel pump.

Carefully position the fuel pump into the fuel tank, being careful not to cause damage to the sender unit arm and associated mechanism.

After ensuring the fuel pump is correctly aligned with the round aperture, press down very firmly ( I used my foot). Then locate the screw ring and turn for about 3/4 of a turn, by tapping it round. This should be sufficient to secure the pump into the tank. If you screw the ring too far the ring will just come off again.

Replace the plastic fuel lines into the pump, noting the coloured fittings. Your new pump may come with new coloured plastic clips.

Allow the diesel fuel to fully prime through the system by allowing the pump to run for 30 seconds with the ignition switched on. Fully depress the accelerator fully and start the vehicle as normal. Air in the fuel will be purged automatically in most cases.

Replace the metal floor cover and screws and the boot floor carpet.

As the old fuel pump will contain diesel fuel it must be discarded in an environmentally friendly way, your local council waste rubbish tip should take it off you.