Black Smoke - Another One

[Ben Griffith]

Hi all,

I am having black smoke issues with my 2009 Titanium edition 2.5l diesel. A bit of history:

- Purchased from a dealer in October 2022. Had a few minor issues like steering rack, ball joints and a few leaky seals here and there that I had replaced
- In January I lost power and started getting black smoke. Had it in with a diesel mechanic who diagnosed as a faulty boost solenoid. He replaced this with a manual boost controller and set it to 17PSI. It was driving nicely with no smoke after this
- Start of April started getting black smoke and no power again. Found that the wastegate actuator had actually somehow unscrewed itself and wasn't pulling the vanes in at all. My mechanic repaired this without having to removed the turbo. Boost has returned to normal, however I still have the black smoke.
- Gave the car a service in Later April - changed oil, oil filter, fuel filter, air filter, and replaced the 3mm vacuum lines going to the boost controller and turbo. Still have the black smoke. Checked the intercooler hoses during this service and could not find any leaks. Cleaned the MAF sensor with proper MAF cleaner.
- Booked a prostream engine carbon clean for the intakes and part of this included injector cleaner being run through the fuel system. Still have the black smoke - in fact not sure if being paranoid but it seems to be worse after this.

Now i've learned a LOT about these engines because of the above issues, however i'm kind of at a loss about what to look at next. There are no other real symptoms eg. no engine light, no rough idle etc to suggest injectors or pump or anything like that. I do notice that the smoke is especially bad down low in 1st and 2nd gear, worse when the engine is not quite up to temp, and i'm not sure if i'm being paronoid again but it seems to not be overly responsive under 2000rpm before the turbo kicks in.

I guess one question is - is there any way to adjust so the boost kicks in sooner? I've played with the manual boost controller which responds and increases/decreases the boost level, but doesn't seem to affect when it kicks in.

I'm using an ODB2 bluetooth module with the Torque app to check the vitals. There are no fault codes. The readings for intake pressure, fuel rail pressure, fuel flow, boost etc all appear very typical compared to those stated here and in other technical forums and details.

Any help would be appreciated.
Cheers

 

[Old.Tony]

Welcome to the forum.

It could be that the boost level isn't high enough. 17psi is slightly lower than nominal (about 20psi).

Also, EGR may be affecting it. This is difficult to check in the older models, but easy to remedy (or at least, remove from the equation). On the vehicle right hand side, a gold tube connects to a widget attached to the intake manifold - that widget is the EGR valve. There are two 12mm bolts that attach the pipe to the valve. Remove these and catch the gasket, then make a copy of the gasket in 1mm stainless, 1.6mm mild steel or 3mm aluminium, but don't put the large hole in. Install and test and see how it goes!

 

[Ben Griffith]

Welcome to the forum.

Thankyou kindly Tony.

I have adjusted the manual boost controller a full turn clockwise which has increased the boost but not the responsiveness. Actually, I wanted to confirm something and you might know the answer - the boost levels I can see in the Torque app, are they showing the output from the ECU that would be trying to control the old boost controller, or would this be the values based on the MAP boost sensor? With a manual boost controller set at 17PSI, we would be talking about the maximum boost right? Because it is basically just a valve.

I have thought about blanking the EGR at least to diagnose EGR valve issues, although not too keen on copping a $30K fine and being defected for interfering with the emissions control. Although I do understand how it is good from an overall preventative maintenance standpoint.

I appreciate your advice.

Cheers

 

[Old.Tony]

I don't use a BCS in my car, I use a Tillix valve. The boost values reported by the ECU are the result of the pressure sensor, not an expectation by the ECU.

You could try the EGR blank simply as an investigative tool. If it works, your EGR valve is suspect. Replace the EGR valve, remove the blanking plate and you're not only compliant, but you nailed the fault.

 

[Peter Coy]

replaced the pressure control valve on mine. Too mmuch black smoke, bit boggy down low, & wanted to stall if you didn't give it a bit trickling around in an intersection. Made so much difference I suspect the original wasn't doing the job properly from day one.
Also put an I drive in it. Change dthe vehicle completely.
Both pretty easy fixes if you do a bit yourself.

 

[Ben Griffith]

Thanks for the above response Tony, I might do some testing when I can with a blank plate and see what results I get.

@Peter Coy do you mean the Boost Control solenoid or the suction control valve? If Boost controller i've already gotten rid of it and it now has a manual valve that can be adjusted. It's currently set around 17 PSI, I jacked it up to about 19PSI and we are making that boost, just still have a bit of black smoke especially down low. If you meant the SCV that is a bit harder to get to from what I understand?
I have a mate who put an iDrive in his 2010 Nav and he loves it too. Might have to look at this also.

Cheers for the advice.

 

[Peter Coy]

The scv. Bit awkward but not a huge job. Made a big difference to how mine behaved. The I Drive changed the whole game again. Most of those earlier diesel navs blow black smoke as you take off. Its how they're timed from the get go apparantly. There is a you tube video that lays it out. The I Drive remappes the fuel setup as you go, & seemed to reduce my smoke issue.
Either way its still going strong heading up from 335000 ks . timing chains done about 5000 ks back. Good luck.
Pete

 

[Ben Griffith]

Hi Gents,

I finally got around to ordering the blanking plate ($7 on eBay like Tony suggested). I popped it in last night and wow, what a difference it has made to the vehicle.

As soon as I installed it, I started the car up to check that all was well with no error codes etc, and looking on the torque app, immediately the efficiency was up around 100% (it used to sit somewhere in the 60s-70s) and even the fuel flow was up by about 1l/h. Drove it and black smoke is completely gone, and my power down low has significantly improved. I think it's conclusive that EGT valve is fucked.

I looked online and these valves appear to go for around $500 . I'm thinking considering the marked improvement in performance and the long term issues caused by the EGR, I'm going to leave the plate in, and only remove it when it's up for rego inspection.

Thankyou so much for the advise gents, much appreciated.

Cheers

Ben

 

[bringthenav]

Agree. My EGR was kangarooted.
Stuck open or something.

Had savage black smoke,
Loss of power on hills followed by more black smoke on takeoff which moves like a lack of fuel, power, then suddenly starts cranking after 5-10 sec. Loss of power under load, heavy black smoking/heavy fuel use,
Loss of power on fway hard to keep 90-100kmh on big hills,limp modes etc.

Fixed now pretty much!!
I can tromp on freeway at 140 if i like, all 6 gears smooth,
Fuel usage down massively,
Stays at 120 even on massive kilometres long freeway hills.

Not limping. Unless i stab it rudely on the freeway, so watching not to do that.. as long as i drive smoothe it holds the kms and boost etc

*Blanked egr, fitted a catch can.
*Fitted a 9drive throttle controller for $40 off alibaba. 2.6 setting perfect.

*Ran diesel treatment 3-4x.
*Few full treated tanks.
*Could do with more.

Black smoke gone entirely after few hundred highway KMs.
Even take off grey smoke much less.

Limp modes mostly gone.
Has it chronically.
*Think scv was slightly sticking

So tightened all intercooler hoses,1 was a bit loose!

*Fitted boost guage to intercooler for permanent easy boost monitoring.
Old school.

Next step.
Fit new EGR as even tho i blanked it after the heater cores,
The EGR must be so rooted there is no heater now lol

And its winter

 

[bringthenav]

I noticed the power improved right away on mine the first trip of 100kms or so of a freeway trip.

Still some smoke.

After a couple more couple hundred km runs all of the smoke fully disappeared.

Performance increased dramatically by then also, as if it needed a good few long runs to clear up.

 

[Old.Tony]

Next step.
Fit new EGR as even tho i blanked it after the heater cores,
The EGR must be so rooted there is no heater now lol

And its winter

EGR doesn't affect the heater. The coolant flowing through the EGR tube is actually cooling the EGR down, not heating the coolant up. Disconnect the hoses from the EGR tube and join them together, then investigate why you're not getting heat - is it a flow problem in the heater matrix inside, or a hose problem in the engine bay?

 

[bringthenav]

EGR doesn't affect the heater. The coolant flowing through the EGR tube is actually cooling the EGR down, not heating the coolant up. Disconnect the hoses from the EGR tube and join them together, then investigate why you're not getting heat - is it a flow problem in the heater matrix inside, or a hose problem in the engine bay?

I had a perfectly working heater before i fitted a blanking plate to the driver side egr out? spot.

I watched 5-6 videos before i fitted plus read a few threads here,
Somewhere i heard someone say if u fit a blank plate to the p/s side at the egr start.. you'd lose your heater,
As no hot exhaust can flow thru to those 2 little pipes at the middle of the egr that go towards the motor)

Now i have zero heating even though i fitted to drivers side like i was apparently supposed to.

Therefore so far i was assuming my egr pipe must be soooo clagged up with carbon, that it not going further thru the usual ouput on d/s had rendered my heater useless to my new egr arrived.

Anyone had the same issue?
I bet some have. 300k on motor.

 

[Old.Tony]

My engine has about 384,000km on it. Driver's side EGR is blanked off (has been for years, I'm still testing it, of course). Heater works quite well. Heater matrix entry on the firewall comes from that EGR cooler. The heater matrix and EGR cooler are "side routes" for the coolant, not the main path.

Another reason for loss of cabin heating is cylinder head issues. Take a good look around the cylinder head for any signs of leaking coolant, and check the oil to make sure it's not milky.

 

[bringthenav]

Hi. Yeh they're pretty solid motors when they want to be for that many kms. Its strange the Heater went out immediately after i blanked that.
It worked very well before.
Not sure if its related, but i had the AC seemingly run out of gas thru summer. I also hear no clicking sound of compressors coming on when i switch on the AC & smelt hints of ac gas while it was still cooling some days prompting me to switch it off or adjust it cooler on the dial that seemed to stop that unpleasant smell.
I'm quite sure i had a working heater right up until i blanked the vehicle though, and remember a few unseasonable freezing nights in Feb, March, April, early May using it.

My head is new & was installed professionally by prev owner w receipts probably under 40000 ago.

No overheats, no steam, no milky oil, no coolant dropping at all.
Thank god tbh

Someone would have had something happen like this before.
Be interesting when i whack on the new egr soon sometime see if it works again right away,
By spring i would regas the ac etc too

 

[Ben Griffith]

I am having a similar issue, the common denominator is that I blanked my egr about 2 weeks ago which resolved a low power and black smoke issue. It also means that it's diagnose my EGR valve was stuffed.

Since then, I seem to have intermittent cabin heating. Even with the heat turned all the way to max, it seems to blow lukewarm air for a bit, then completely cold, then cuts back in later with warm air. It used to be piping hot when it got up to operating temp.

I also had an issue a couple of weeks back where one of those useless plastic fittings split in the heater hose going through the firewall. I documented on here how I fixed that with a bit of heater hose. There are no leaks around the repair or anything to lead me to believe this has anything to do with it.

Engine is also NOT overheating, gave it a good kick up a couple of hills to test it out, and with foot down up a steep hill we hit 110 and holds and even brings the temp down while still throttling. Also quick to come back down to near 96 while cruising. The heat in the cabin seems to come back only after reaching the high temps, and cools a few minutes after it settles again. All normal temps for my engine. Coolant level is good. No leaks.

When it was happening the other day, I pulled over and felt the engine and hoses. Radiator was hot, hoses to and from the heater core were only lukewarm. Thermostat pipe was barely warm. I am wondering - I live somewhere with sub zero temps and the days have been cold lately, could the thermostat simply not be actually getting up to temp and not opening? Although if this was the case I would expect engine overheating problems too. Is it worth putting a bit of thermal wrap around the thermostat housing?

I'd be keen to hear any thoughts

 

[bringthenav]

I froze and shivered last night on a 10 min drive from the shops because of this B.S issue. Its one cold winter this year. I reckon as soon as we order and whack on new Egrs the issue will be gone immediately.

I imagine a new Egr might work well for 100,000km and outlive my motor,
I need the heater badly so i am doin it

 

[bringthenav]

Among other issues i had yet another annoying limp mode,
with full emgine cutout and conking!!

While not fully warmed up,2 min after leaving home last night, thankfully in a quiet street this damn time.

I popped the hood,
enjoying my nice new bonnet struts,
and assumed the position.. lol

Wouldn't restart after trying key,
Pissed me off as i had to limp around a corner to get out of peoples way with it half conking out,
And my injectors probably beong half destroyed. I could throttle someone !!

Pumping the not yet replaced soft primer bulb 20 times.
Okay restart, okay driving ok.

I have a replacement primer.
300,000, blanked,catch can, boost guage, perfect solenoid,
possible slight sticky suction control,
All boost clamps.. afaik! Tightened,

Drives well for between 200-500km then issue comes back of conkout as if i have fricking air in my fuel system.

Will pull the primer tomorrow and update in a cpl weeks if it's all it is.
It might be all it is!
Fingers crossed

Plug n pray

 

[Ben Griffith]

So a development today, this morning drove my son to footy, it was about 2 degrees outside. Noticed heater was blowing cold even though I'd warmed her up and we got up to 96 degrees temp, which is fairly normal. Didn't think much of it and it was a short trip.

However, after the game I was driving into town to take the kids to a bday party, hit one of the big hills near my place and the engine coolant climbed to 110...115...didn't come back down, needle heading for overstemp. When I got off the hill the temp stayed up near 115 and barely came down. Knew something was up so very slowly limped it home. Found that the overflow on the resovoir had been bubbling over and spewing coolant out everywhere.

Topped it back up, took it for a drive and it stopped overheating, however the inlet pipe to the EGR cooler is hot, the outlet pipe which heads off to the heater is cold. So without a doubt this is where my heater is falling down.

I put the nose up in my driveway and ran it with the caps off trying to bleed any air out, I have no bleed valve (even the old plastic elbow I removed a few weeks ago didn't have it), drove it again with still no heat. I'm currently waiting for it to cool down again to have another look around.

Surely an air bubble is the only thing that would cause this? I'll be squeezing the shit out of some pipes this afternoon.

 

[TCN]

cracked head, the heads are made of cheese, slight over temp and they are knackered

 

[Ben Griffith]

I think you might be right...

Currently waiting for a tow. Lost all coolant again through the overflow, topped it back up and its constantly bubbling and steam even with cold water. I'd say it's a head for sure now. No milky oil though.

I'd have to say this has been my first Navara and I'm not overly impressed. Since October I've had: Faulty boost solenoid, faulty turbo actuator, cracked plastic heater core elbow, failed EGR valve, and now this.

To be honest, these are probably the last vehicles I would recommend to anyone.