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October 13

Servicing Diesel Injectors

Diesel fuel injectors operate at extremely high pressures. This helps to keep them clean, thus diesel injectors do not suffer from clogged nozzles to the same extent as petrol injectors. However over time diesel injectors suffer wear and require servicing. As a rough guide diesel injectors will need to be serviced after 100,000 km, but this can vary widely with the vehicle.

At Morrison Diesel we offer the service of pop testing mechanical diesel injectors. This procedure requires specialist equipment and is used to check: 1. the pressure at which the injector opens, and 2. the spray pattern from the injector. Sometimes we detect an incorrect opening pressure which is typically remedied by replacing a shim or a spring. However it is more common to find a problem with the spray pattern and in this case the best remedy is to replace the injector nozzle, a relatively cheap and effective option.

It should be noted that symptoms often attributed to injector problems (e.g. black smoke, fuel efficiency) can also be indicators of different issues with the vehicle. So in some cases when we test injectors they perform well, and diagnosis of the problem will move on to other areas.

Occasionally we encounter diesel injectors which will benefit from cleaning, but this will bring only limited improvement, and in the majority of cases replacement of the nozzles is a better option.

There is plenty of advice on the internet regarding products and methods which claim to clean dirty diesel injectors. While it may be uncertain whether dirty diesel injectors are really the problem at hand, it is certainly true that in some instances a fuel additive will assist in cleaning a dirty fuel system and bring some improvement in the performance of a diesel vehicle. However, there may be an underlying problem such as a worn injector which will need to be identified and addressed in due course.

After diesel injectors have been serviced it is necessary to re-test them in order to confirm that they are performing to the correct specifications. At Morrison Diesel you can be confident that your diesel injectors will be serviced by an experienced diesel mechanic. We would strongly advise against DIY servicing of your diesel injectors as specialist knowledge and equipment is required to carry this work out safely and correctly. Please call us at Morrison Diesel if you require further advice regarding your diesel injectors.