There are many possible reasons for this, but they can be broken down into three basic categories:

• Your vehicle is in need or is overdue for a service. Blocked air filter, incorrect valve clearances and other such easily remedied faults can often be the cause, and you are advised to get them attended to first before investigating either of the next two possibilities.
• Worn diesel injectors.
• Worn or faulty diesel pump.

The Glow Plug light can sometimes take a long time to go out by design. If it is staying on for an abnormally long time however, this could be an indication of damaged glow plugs or a faulty glow plug controller.

Faulty glow plugs or glow plug controller and overall engine wear are the two most common causes of hard starting. Glow plug issues are normally very easily diagnosed and repaired. A simple compression test will give a good indication of the condition of the engine and whether it requires any major work.

All diesel engines will produce some smoke on first start, and some engines tend to produce more than others. It is entirely possible that this is normal behaviour. However this can also be a symptom of the problems mentioned above regarding hard starting.

The usual cause of this is worn diesel injectors. However the simple regular servicing issues such as filters, valve clearance and so on can also be at fault, therefore it is best to address them before assuming the injectors are the cause.

This problem is typically caused by worn injectors that leak fuel and allow the engine to keep firing. This fault is most commonly seen on Nissan TD42 powered vehicles, but can also occur on other engines.

The rules regarding vehicle emissions in New Zealand are currently changing quite rapidly. At the present time there is a 'Visible Smoke Test' rule in effect, and the requirements for the test can be viewed at Land Transport NZ's website: HERE

Unfortunately there is no simple answer to this question, as the requirements will vary greatly depending on the particular vehicle, its age, and milage.

For indirect injection engines (traditional diesel engines) you are advised to service after 80-120,000kms. Direct injection engines typically do not require the injectors to be serviced unless a specific fault occurs.

Servicing injectors returns them to effectively new condition, so there is no real gain to be made from buying new ones. The cost of servicing injectors is also typically about 20% of the cost of replacement.

As with injectors, pump servicing represents about 20% of the cost versus buying new. Diesel pumps are also typically not available to be purchased new off the shelf.

All parts supplied by Alltech will be covered by their standard manufacturers warranty, which naturally varies with different manufacturers. Any work done by Alltech will be stood by without question.

The simple answer is that there are many possible reasons for diesel leaks. Some may be as simple as a gasket replacement, some may require major servicing. You are advised to take the vehicle in to be assessed rather than rely on an inaccurate phone diagnosis.

The diesel fuel pump will require servicing. Front fuel pump seals fail on these pumps, and the cutting out is a symptom of the pump having been drained of fuel.

There is not necessarily a problem with your vehicle. There are many different variants of Terrano, and they have quite different performance characteristics.

There are numerous models available in the New Zealand market, some of which are better than others. However the scope of this question is too large to be answered in a few sentences. If you are looking at purchasing a particular vehicle then feel free to contact us to discuss the possible pitfalls and arrange for a pre-purchase inspection.

If you haven’t yet started the engine then don’t do so. Drain the fuel tank and refill it completely with diesel; no harm will have been done. If you have already run the engine for a short period then you will need to drain and replace the fuel and replace the fuel filter. If you have run the engine for an extended period of time then there may have been damage caused to the diesel pump; naturally this will require an inspection to establish the damage.