Jump to content


For the diesel experts


Recommended Posts

The following is going on for 10.000 km now.

My Navara D40 has now 140.000 km on the clock, I use 90% of the time always the same 2 pumps, a Caltex and a Shell pump and use the standard diesel.

However I had no smoke or bad performance I changed the diesel filter at 130K, but I used a third party filter. My mistake.

I noticed that from that day on I had quite some black smoke when accelerating.

I have no performance issues, only black smoke, though I notice that when I switch of the engine it sounds as if it does not shut down immediately. Like the pistons go up one more time, and I'm not sure if it did this previously.

After experiencing this for 1000 km I decided to switch the filter with an original one.

When I removed the filter I noticed it wasn't completely full, which I considered strange but wrote down to being it an inferior part.

After changing to the original filter I didn't see any improvement in the black smoke.

I reset the ECU, something I found on a Navara forum, as they said this should be done every time the filter is changed. Still no improvement.

The last 2 tanks I decided to change to the Shell v-power diesel, but still no improvement.

Today i removed the filter again to check and noticed that it wasn't even half full.

So is this normal or does this give an indication of what the problem may be?

Link to comment
Share on other sites

A lot of diesels have to have the filter and fuel line primed after replacing the old filter. Did you push the primer plunger till it was to hard to push? Black smoke comes from incomplete combustion.

Link to comment
Share on other sites

I changed the air filter 10K km ago, and I have tried with the filter removed so should get maximum airflow, but black smoke still there.

For those suggesting I bled the filter insufficiently please take not the aftermarket filter was fitted for 1K km, and the genuine filter for 9K km already when I removed it to check.

I would assume that any left over air in the system would have be gone already after that time.

I also think if there was air in the system it would be visible in the performance or the engine not running properly while stationary, but none of that is the case.

Link to comment
Share on other sites

Berty you say that you reset the ECU when you changed the filter. How did you do this ? Did you plug in a OBC analyser and do a DPF regeneration / reset ? The black smoke has nothing to do with your fuel filter in my opinion but I would be looking to get the injectors tested. Are there any engine system lights on the dash lit ?

Link to comment
Share on other sites

Berty you say that you reset the ECU when you changed the filter. How did you do this ? Did you plug in a OBC analyser and do a DPF regeneration / reset ? The black smoke has nothing to do with your fuel filter in my opinion but I would be looking to get the injectors tested. Are there any engine system lights on the dash lit ?

No it is some code. This is the original source, but you can find it on the official Navara forums as well.

http://www.blue-print.com/techtip/navara/INF121%2004%20BP%20TIP%20Navara%20fuel%20pump%20ECU%20Reset.pdf

No warning lights on the dash.

It is a coincidence that it started at the time i fitted the aftermarket filter, maybe some dirt may have get in the injectors because of that, but I actually try to find an explanation also why the filter is half empty when I unscrew it.

My thought is that it should be overflowing.

Edited by Berty100
Link to comment
Share on other sites

I don't thinks its fuel filter related.

Check all the hoses between the outlet (boosted air) side of the turbo and inlet manifold. Perhaps a hose is loose fitting or split.

The MAF sensor is before the turbo and would sense correct air volume meaning ECU is fueling for a volume of air that's perhaps leaking out. Result = black smoke.

Link to comment
Share on other sites

I don't thinks its fuel filter related.

Check all the hoses between the outlet (boosted air) side of the turbo and inlet manifold. Perhaps a hose is loose fitting or split.

The MAF sensor is before the turbo and would sense correct air volume meaning ECU is fueling for a volume of air that's perhaps leaking out. Result = black smoke.

I want to add another minor info. I have since new the EGR valve blocked off, to prevent the air inlet to get clogged.

When I switch on the contact, and switch off everything like aircon and fan blower, there is a constant very low sound buzzing noise under the hood.

I would think that it is the diesel pump, but then it should stop once the fuel system is on pressure, but it keeps buzzing indefinitely.

Can not locate where the noise exactly originates form.

Link to comment
Share on other sites

I wonder actually which one is the injector in the picture, is it the one on top are are they to the left?

I notice that first one on top of the engine is very greasy, not sure if this is from spill during oil fills or this "thing" is leaking.

post-249019-0-81502900-1468731878_thumb.

Link to comment
Share on other sites

Very Old n Dirty, never clean it.?.

Thanks for the very helpful comment, but yes it gets cleaned, the picture is taken with the engine cover removed.

The engine cover nor the engine get unmounted when the engine gets cleaned, and the grease is only on the spot in the picture while the engine itself is a bit larger.

Link to comment
Share on other sites

Injectors are on the left ,with the metal pipe going into the block,

not sure about the one on the top,could be a pre heater.

It's a wonder your truck is running at all if the if the fuel filter is

half full,meaning you have air in the system,many memory's

of bleeding knuckles loosening the air bleed nuts on our old

trucks,they would not run unless you got all the air out of the

system.

the diesel they sell here ,the quality should be a lot better,

I have even seen new trucks with black smoke when

accelerating ,Buy some STP injector cleaner and add to

diesel as instructed on the bottle,I could certainly feel the

difference with my old Isuzu after using it a few times.

regards Worgeordie

Link to comment
Share on other sites

Injectors are on the left ,with the metal pipe going into the block,

not sure about the one on the top,could be a pre heater.

It's a wonder your truck is running at all if the if the fuel filter is

half full,meaning you have air in the system,many memory's

of bleeding knuckles loosening the air bleed nuts on our old

trucks,they would not run unless you got all the air out of the

system.

the diesel they sell here ,the quality should be a lot better,

I have even seen new trucks with black smoke when

accelerating ,Buy some STP injector cleaner and add to

diesel as instructed on the bottle,I could certainly feel the

difference with my old Isuzu after using it a few times.

regards Worgeordie

The the thing on the top isn't a pre-heater, because if I disconnect it the engine will run on 3 cylinders.

There is no problem with the performance, engine runs smooth, no knocking from the injectors or so but the filter is half empty when i remove it.

I of course bled the filter when installed, but there is no nipple, just remove the tube until diesel pours out.

Now when I manual pump on top of the filter I can pump 2-3 times before it feels the filter is full.

When I start and stop the engine I can pump 2-3 times again.

Edited by Berty100
Link to comment
Share on other sites

Can only add that Black smoke indicates unburnt fuel (blue smoke would be oil)

I would go for using premium fuel and adding the injector cleaning fluid for the next couple of fill ups. Also give the motor a good hard run to clear out muck build up in the engine and exhaust system. (Give it a good thrashing it but not like in Faulty towers biggrin.png )

Of course another indication of black smoke is a faulty turbo, but I think you have eliminated that already.

Re your buzzing noise when ignition is on but engine not running, Have a look here:- http://au.toyotaownersclub.com/forums/topic/21682-hilux-07-diesel-clicking-noise-when-ignition-is-on/

Not the same make or model but could be the same noise. Nothing to worry about.

smile.png

Link to comment
Share on other sites

In your pic - the steel line contains the diesel fuel. The electric wire opens the fuel injector, on signal from the ECU, pulse width depending on signals received from the various sensors. Both connected to the fuel injector.

Black smoke is caused by unburnt fuel. Causes can be a dirty air filter, dirty injectors, defective MAF sensor, or others.

Always a good idea to use diesel fuel conditioner from new. Keeps injectors, intake valves, manifolds clean. Same applies to FI gasoline engines.

post-242372-0-90235400-1468790080_thumb.

Edited by canthai55
Link to comment
Share on other sites

In your pic - the steel line contains the diesel fuel. The electric wire opens the fuel injector, on signal from the ECU, pulse width depending on signals received from the various sensors. Both connected to the fuel injector.

Black smoke is caused by unburnt fuel. Causes can be a dirty air filter, dirty injectors, defective MAF sensor, or others.

Always a good idea to use diesel fuel conditioner from new. Keeps injectors, intake valves, manifolds clean. Same applies to FI gasoline engines.

attachicon.gifFI.JPG

Thanks, the reason that the injector is so dirty, could that be an indication what the problem is?

I have now cleaned that injector and will monitor if there are some leaks in that area.

Link to comment
Share on other sites

I doubt that any oil is leaking up thru the injector. Probably just a little bit of spill when changing oil. As a plastic cover hides it all, a small bit got under the cover, and the oil attracted the dirt. If clean now, keep an eye on it, but if I had to predict I would say no.

Link to comment
Share on other sites

Fuel filters and fuel leaks will not cause black smoke.

A too high fuel air ratio will. This is usually caused by in order of likelihood the following-:

1. Clogged air filter.

2. Leaking or split inlet hoses.

3. Leaking or split inter-cooler (This is where I'd be looking next)

4. Faulty MAF sensor telling ECU more air is going in than actually is causing over-fueling, but items 2 and 3 cause this as well.

5. Faulty injector putting too much fuel in - rather unusual and not very likely IMHO.

6. Bad turbo, but this would reduce air volume and thus ECU should reduce fueling accordingly.

Black smoke almost always due to high a fuel air ratio. From air leaks or restrictions or a cheapo chip tune which over-fuels to gain power.

Blue smoke is normally oil being burned either from piston ring blow-by, valve guides or turbo bearing seal.

White smoke is from water getting into the combustion chamber - most likely from a head-gasket failure.

I'd be ruling out everything on the air intake side as the most likely problem and also the cheapest and simplest fix. Note split hoses might not be obvious unless the engine is working under-load, revving in neutral with the bonnet up everything will seem normal.

Edited by Pomthai
Link to comment
Share on other sites

I'd be interested to know how you cleaned the injector. The average weekend mechanic would not have the equipment for such a job, and why only clean one???

Reading back over the OP the problem seems to have started after changing the fuel filter. Usually this would not cause the symptoms describe but I'm a believer in checking the last thing done before a problem started.

With diesel's the system has to be primed after doing any work on the fuel delivery system to remove any air in the system. I know this has been done but to be absolutely certain I would suggest crack the nut on the injector while the engine is running, at idle, and let some fuel pump out.

To put it another way with the engine at idle just slightly loosen the nut on the pipe on top of the injector. Be careful to just loosen it slightly as fuel is under pressure and will squirt out. After you get a couple of squirts close the nut and go onto the next one. Do all injector nuts this way to ensure there is no air in the system.

smile.png

Link to comment
Share on other sites

I'd be interested to know how you cleaned the injector. The average weekend mechanic would not have the equipment for such a job, and why only clean one???

Reading back over the OP the problem seems to have started after changing the fuel filter. Usually this would not cause the symptoms describe but I'm a believer in checking the last thing done before a problem started.

With diesel's the system has to be primed after doing any work on the fuel delivery system to remove any air in the system. I know this has been done but to be absolutely certain I would suggest crack the nut on the injector while the engine is running, at idle, and let some fuel pump out.

To put it another way with the engine at idle just slightly loosen the nut on the pipe on top of the injector. Be careful to just loosen it slightly as fuel is under pressure and will squirt out. After you get a couple of squirts close the nut and go onto the next one. Do all injector nuts this way to ensure there is no air in the system.

smile.png

I cleaned the dirty part visible in the picture.

Link to comment
Share on other sites

If there was air in the system it would run rough on idle. As others say, its very unlikely the 2 things are connected. Its over fuelling for some reason or short of air. I'm not well up on modern electronically managed common rail diesels, but I'd get the computer read to see if there are any fault codes. Clear them all off, drive it for a few days then read again.

Link to comment
Share on other sites

I'd be interested to know how you cleaned the injector. The average weekend mechanic would not have the equipment for such a job, and why only clean one???

Reading back over the OP the problem seems to have started after changing the fuel filter. Usually this would not cause the symptoms describe but I'm a believer in checking the last thing done before a problem started.

With diesel's the system has to be primed after doing any work on the fuel delivery system to remove any air in the system. I know this has been done but to be absolutely certain I would suggest crack the nut on the injector while the engine is running, at idle, and let some fuel pump out.

To put it another way with the engine at idle just slightly loosen the nut on the pipe on top of the injector. Be careful to just loosen it slightly as fuel is under pressure and will squirt out. After you get a couple of squirts close the nut and go onto the next one. Do all injector nuts this way to ensure there is no air in the system.

smile.png

I cleaned the dirty part visible in the picture.

Cleaning the injector externally will not help unless there is so much oil it is interfering with the wiring harness connection, in which case there would most likely be other problems.

Black smoke and running on are caused by not enough air or too much fuel. If there are no issues with the air charging system (Turbo ducting MAF etc), the fuel system needs to be checked.

Common rail injectors are expensive and delicate. A small amount of contamination or wear can affect the precision valving inside the injector. Injectors can be checked if they are sealing and metering the correct amount of fuel.

A Nissan dealer should be able to check the fault codes and refer to a suitable local diesel repair shop if there is a (repairable) injector fault.

Link to comment
Share on other sites

I'd be interested to know how you cleaned the injector. The average weekend mechanic would not have the equipment for such a job, and why only clean one???

Reading back over the OP the problem seems to have started after changing the fuel filter. Usually this would not cause the symptoms describe but I'm a believer in checking the last thing done before a problem started.

With diesel's the system has to be primed after doing any work on the fuel delivery system to remove any air in the system. I know this has been done but to be absolutely certain I would suggest crack the nut on the injector while the engine is running, at idle, and let some fuel pump out.

To put it another way with the engine at idle just slightly loosen the nut on the pipe on top of the injector. Be careful to just loosen it slightly as fuel is under pressure and will squirt out. After you get a couple of squirts close the nut and go onto the next one. Do all injector nuts this way to ensure there is no air in the system.

smile.png

I cleaned the dirty part visible in the picture.

Cleaning the injector externally will not help unless there is so much oil it is interfering with the wiring harness connection, in which case there would most likely be other problems.

Black smoke and running on are caused by not enough air or too much fuel. If there are no issues with the air charging system (Turbo ducting MAF etc), the fuel system needs to be checked.

Common rail injectors are expensive and delicate. A small amount of contamination or wear can affect the precision valving inside the injector. Injectors can be checked if they are sealing and metering the correct amount of fuel.

A Nissan dealer should be able to check the fault codes and refer to a suitable local diesel repair shop if there is a (repairable) injector fault.

Do people never read posts before commenting? I think I clearly said

I have now cleaned that injector and will monitor if there are some leaks in that area.

Link to comment
Share on other sites

Do you have a fuel pressure gauge?

There could be multiple issues but the fact your fuel bowl is only half full is one issue.

Its not a result of failing to bleed the system because after 1K kms any air in the system has been removed.

An aftermarket fuel filter would not be the issue so quickly unless it was not seated correctly but the paper element itslef would be fine at 1K kms.

Just my own 2 cents as a long time diesel owner.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.