Go Back   The Navara Forum > Tech Talk > General Tech Talk

Thread Tools Display Modes

Old 08-02-2018, 05:32 AM
240voltz 240voltz is offline
Junior Member
Join Date: Oct 2016
Location: Victoria
Posts: 9

Originally Posted by ericcs View Post
don't forget to check these hoses on the drivers side, need to take the engine cover off check!

Thanks errics. I looked at your photo and I only have one hose there. The pipe on the left has been blanked off. It looks like a hose has also been blanked off at the air intake.

Any idea why that would be?

Got the ute 2nd hand and I know I haven't done it....
Reply With Quote
Sponsored Links

Old 09-02-2018, 05:16 AM
Vomitbomb Vomitbomb is offline
Junior Member
Join Date: Apr 2012
Posts: 29

Hi Tony,

Originally Posted by Old.Tony View Post
You've replaced just about everything that causes these dramas except for the vacuum hoses. I'm not sure if the 2011 Thai builds used a vacuum turbo actuator or the electronic one - the electronic ones from 2011 fitted to Spanish D40s had some troubles but these were replaced under a recall (and of course some cars could slip through the cracks).

Vac hoses are a PITA. I've replaced mine 3 times (285,000km clocked up on the way home from Bathurst earlier today). $20 at AutoBahn for 3m of 3mm ID vac hose - $15 at Supercheap and I can't tell the difference between the two, really.
I have a vacuum tube going to the actuator on the turbo. Myself and a mate checked them all out. Can't see any obvious signs of damage but it may be worth just replacing them anyway. The boost seems fine using the ODB2 bluetooth adapter. It sits at about 19psi under load. It's hard to tell with the rest of the engine moving around but the actuator arm appears to be moving ever so slightly at idle.

Should I have any boost at idle? It bounces between 0 and about 0.2.

If the boost controller was connected wrong it would be pretty obvious wouldn't it?

Originally Posted by Old.Tony View Post
Carefully examine the EGR pipe (gold tube that runs around the front of the motor). If they replaced the valve they may have removed the block. If there's an issue with the EGR pipe, you could be losing exhaust pressure (which drives the turbocharger). You can usually spot issues with the EGR tube because they leave black soot where the exhaust is escaping. This will reduce your boost levels.
I couldn't find any soot near the EGR pipes.

Originally Posted by Old.Tony View Post
Something else that affects boost (and therefore power, and air for combustion, and therefore the amount of smoke) is the dinky little gasket on the exhaust manifold where the turbocharger bolts to. Mine has twice turned into a reed instrument - at certain engine RPM it sounded like a very, very poorly played clarinet. You should notice the sound!
Definitely can't hear a sound like that.

My mate mentioned that my fan clutch felt a bit stiff and the fan spins regardless of engine temperature. Is that normal? A while ago I thought the car sounded a bit more fan-like when driving but didn't concern me enough to look into it.
Reply With Quote

Old 09-02-2018, 09:39 PM
Old.Tony's Avatar
Old.Tony Old.Tony is offline
Join Date: Oct 2009
Location: Mid Coast Region, NSW, Australia
Posts: 14,977
My Mood:

Everything I've described focuses on the induction side (pressurised air). There are two more possibilities (apart from sensor aberrations which are unlikely given that you've replaced the MAFS, leaving just the fuel rail pressure sensor):

1) Excessive blowby dampening combustion

2) Injector faults

Neither is good nor cheap to resolve. Excessive blowby caused by stuck rings is probably the easiest but if it's worn bores you're up for a resleeve/hone+oversize piston/rings. The simplest way to determine this is to redirect the PCV output to atmosphere temporarily (you will have to block the intake pipe where the PCV connected). Drive the car again and see if the smoke level changes. If it does, blowby is the culprit. If it doesn't change, your rings/pistons/bores are probably fine.

It could be injectors, over-doing it. The most common reason is a faulty FRPS returning a lower voltage than it should. This is sometimes due to poor engine earth and sometimes it's the actual connector. It could also be the connector to one or more injectors - most of these issues are usually caused by someone pressure washing the engine bay.

There's no use examining the fuel rail pressure in any device monitoring the ECU because it will look normal, while the rail is actually showing a higher real pressure. This sometimes happens when a chip is installed.

If an injector is 'dribbling' you'll get the black smoke issue but the engine will run a little rough as one or more cylinders is overfueled. It's unlikely that all 4 injectors will start misbehaving the same way at the same time (producing a smooth output) unless there's a harness issue (again, usually caused by pressure washing the engine).

Fixed the connectors by unplugging/replugging them a few times and tell the mechanic to keep his pressure washer out of the engine bay.

Injector replacement by Nissan will cost upwards of $4K, and $5K if they replace the fuel rail which they will do if they suspect the FRPS is faulty - because according to Nissan, the FRPS can't be separated from the fuel rail. Not entirely true, but ANY work on the fuel rail needs to be done carefully and properly because the pressure within, under normal operation, is enormous - the YD25s ran at up to 1700BAR and the V9X up to 1800BAR (1BAR = 14.5psi, so YD25 up to 24K psi and V9X up to 26K psi).

Check out the FAQs by clicking here!

"Money can't buy happiness, but it does make misery a lot easier to deal with."
Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT +1. The time now is 05:37 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
| Home | Register | FAQ | Members List | Calendar | Today's Posts | Search | New Posts |