How to Bulletproof Your Nissan Patrol’s ZD30 Engine

If you own a Y61/GU Nissan Patrol with a ZD30 3.0ltr turbo diesel engine, these are invaluable tips to help you increase the life expectancy of your engine……

The ZD30 engine has suffered a poor reputation for premature failures including melting/cracking pistons and overboosting, largely due to some common issues. These engines run a variable vain turbocharger with boost controlled by the ECU, and to meet stringent european emission standards run an exhaust gas recirculation (EGR) system. Running fairly high boost levels from factory causes the ZD30 to be a heavy breathing engine and oil vapour is forced into the inlet tract contaminating the Mass Air Flow sensor (MAF), working its way through the intercooler and into the inlet manifold. The EGR system can turn this oil vapour into a thick tar like consistency, blocking inlet runners, which in turn can lead to some cylinders running rich and some lean, resulting in melted pistons…

What can be done to maximize engine life?

1. Fit an oil/air seperator (catch can). This will reduce the amount of oil vapour/blowby entering the air inlet system.

2. Regularly clean the Mass Air Flow (MAF) sensor located in the inlet pipe near the airbox. A contaminated MAF sensor can cause faulty signals to the ECU resulting in overboosting. Suitable MAF cleaners are available from your local auto parts store.

3. Fit a boost gauge and an exhaust gas temperature (EGT) gauge. Whilst this won’t prevent anything, it will give you a heads up of any warning signs.

4. Fit a free flowing exhaust system, this will lower EGT’s dramatically. We fit and recommend 3″ mandrel bent exhaust systems.

5. Never fit a “Chip” without doing the exhaust system as well. A chip will increase the amount of fuel into the engine, increasing your exhaust gas temperatures, so a free flowing exhaust system is required to lower the EGT’s. We use and recommend Steinbauer and DP chips.

6. If you are noticing boost pressure spikes over 20psi (upto 25psi is not uncommon), fit a boost limiting device such as a dawes valve. These can be set so that the turbo can’t boost over say 18psi…… This is a bandaid not a cure, as their will be other issues causing the overboosting.

7. If your intercooler looks as though it has oil leaking from it, it can also leak boost pressure. Replacement units where the tanks are welded on instead of the factory crimp fittings are available.

8. Have your inlet manifold removed and cleaned. We have seen inlet runners closest to the EGR almost 50% blocked.

9. Although illegal, their are EGR blank off kits available.

10. ZD30’s need regular oil changes, every 5000k is recommended.


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