nissan navara,,rougghhghh idle,,

[bastiaan m bok]

hi,just joined the navara forums..I live in aruba, and imported a nissan navara from holland. this is one great truck,but I think I have run in a big problem.
for the first month the truck ran great,but then slowly began to detoriate.the problem is not in the high end,but in the low. the idle becomes very rough,car shudders..and what I also noticed is that I have a lot of back pressure when i remove the oil filler cap.I know a thing about diesels,and know this is not normall..now my concern is the cetane rating from the aruba gasoil..
I know the navara needs at least a 50 cetane rating,,and in aruba it is always been a bit of a mystery what you get. from what I understand so for,,it is in the 44 range.could this be the cause right now of the rough shuddering idle and the back pressure issue??I mean, when the oil filler cap is removed,you reallly feel it blowing air out..hope you guys can give me some good news or advice on this one.
thanks so much,,keep it up.
cheers
Bastiaan M bok

 

[Bluenavara]

Goeie morgen Bastiaan en welkom!

I suspect the fuel filter needs replacing. If that on its own doesn't do it, the MAF may need cleaning as well. But start with the fuel filter.

 

[Old.Tony]

I wonder if they've blocked off the PCV. There's a hose that comes out of the top of the engine block at the rear of the camshaft cover and it connects into the air intake just in front of the turbocharger. If you remove it from the turbocharger and idle the engine over, you should get some gas coming out (it's created from blow-by). If there's no gas coming out at all, the hose may have a blockage. It's a good idea to connect this hose through to a catch can anyway). This may not fix the bad idle - but you shouldn't have a highly pressurised crankcase, it should be venting to your air intake.

The fuel filter might need replacing, as Blue says - so be prepared for that. Watch the seals as you replace it and don't overtighten the clamps on the hoses, it will create a leak which will cause the car to not start for about 30 seconds of turning over after the car has been off for a while.

I'd look at the MAFS first. It's in the rear of the air tube just outside of the air filter box on the way to the turbocharger. Be very careful with it (it costs $400 over here!) just spray some electrical contact cleaner into it.

 

[bastiaan m bok]

now i have another problem,and could be related to the whole problem.
the truck has become hard to shift gears,,and the is a klunking rattling noise coming from the gearbox when started cold. if you depress the clutch it goes away,but halfway it becomes a bit winding/fast rattle noise,,,could this be the release bearing or worn pressure plate? or the inputshaft bushing in the flywheel?? hope someone can shed some light again.cheers
Bastian

 

[kevinm1962]

that sounds a bit like mine did when the flywheel crapped itself how does your clutch pedal feel and the rough idle check your fuel filter see whats in there

 

[ONLOCK]

firstly what model navara do you have. sounds like a pcv issue where there is a blockage or something in the pipe, cetane rating shouldnt create more pressure in the rocker cover or sump.

the other noise you described sounds like spigot bush or input shaft bearing, could also be thrust bearing hard to tell exactly without hearing it for myself