Nissan Navara Diesel Problems

The DPF requires a certain drive cycle to do the automatic burn it must do to rid itself of the accumulated carbon. Your driving cycle obviously doesn't meet the criteria so the automatic burn hasn't been done and the dealer has attempted a forced burn in an attempt to save the DPF. In one sense you're lucky that it only cost $3200 as many people find they also have to replace the catalytic converters and the cost can climb as high as $6000 or more when that happens. You might have a case against Nissan, consult the consumer affairs people in your state and get their advice.

We were asked if it was necessary to change the timing chain on a D40 Navara and we correctly advised the reader that it wasn't. There is no requirement to change the chain regularly as there is on engines with timing belts, but chains do wear and sometimes they loosen or even break as we reported in our used review of the D40 a few weeks ago. Of course, when that happens you must replace the chain. It's pretty easy to hear a chain when it's loose, there's usually a loud rattling noise from the front of the engine. If you hear such a noise best get it checked out before you do some serious damage to the engine internals.

No it's not normal for a modern diesel to blow a lot of smoke. It sounds like it's too rich, check the fuel pump.

I'd be inclined to take the advice of your mechanic, but if you are still concerned get the opinion of another mechanic. It should be easy, simply by listening to it, to determine where the noise is coming from, and from that whether it is a timing chain or not.

Heavy black smoke is normally a sign of over-fuelling. You could try another Nissan dealer, as not all dealers are up to speed on diesels, or go to an independent Nissan service agent, such as Jerry Newman at Cheltenham Service Centre (03 9583 0500).

Check the injectors, your problems are most likely there.

Nissan's response isn't acceptable, and you're right, the EPA  would probably put your car off the road if they saw it. It isn't  normal, and sounds like it's getting too much fuel when accelerating.  I would have a diesel engine specialist check it; I'm sure they would  be able to find the cause of the problem for you.

We haven't been alerted to the injector problem, so it's something else Navara owners should be listening for. With all the problems occurring today, you could conclude that carmakers have been cutting costs.

There are reports of engines failing, but those that have appear to have failed because they weren't serviced by the book. It's important to religiously service the Navara, and use the Nissan recommended oil. The failures we have heard about are mostly failures of the camshaft, cam timing gear etc that have led to more serious damage. It's believed the initial failure of the cam or cam gear is due to a lack of proper servicing, leading to blockages in the oil passages feeding the top of the motor.

If it were normal why would they clean the EGR valve and reset the fuel pump? Clearly there is a problem, either with the pump or the injectors, as it seems to be getting too much fuel. Take it back and demand a real fix.