Technical 2005 2.8JTD blck exhaust smoke underload

[oldgeo68]

Hi,
Australian , Queenslander, in need of advice how to proceed....
(very)excess black smoke when accelerating under load . Low mileage (77000km), manual, motorhome 3800kg GVM, uses no oil, starts easy, runs smoothly, filters OK.....uses approx 14litres per 100km when would expect around 10...no faults show on computer scans. Owned 6 months, driven 5000km and like it except for embarrassing trail of black smoke.
Thought it must be faulty EGR / clogged intake etc until found it doesn't have one. Dealer recommended injector and fuel pump removal and testing....cost quoted of A$2000 just for diagnosis....sounded like a ripoff especially as smooth running / easy starting don't sound like injectors.
Any recommendations for a check list based on probability / least cost first??? Faulty Air mass sensor? (overread??)
All suggestions welcome.

 

[errolmorris]

Hi Oldgeo68.
I have just fitted a new engine to my van (3 litre) and while it starts beautifully and runs smoothly, it is billowing black smoke under load. My son drives it to work every day with a round trip of just over 200 kilometres each day.
It is a 2008 XLWB with 107,000 on the original motor and after looking it over after removal, it seems that there was some dodgy stuff done to keep it running for a short time until it died on me a few years ago.
I haven't looked into it as yet, but I will see what I can do with the MAF sensor as far as cleaning it goes and I'll be looking at the fuel pump just in case it's not up to the job.
My van has been sitting idle for almost 3 years without a running engine, so I expect a few issues to be forthcoming.
If I get to it this weekend, I'll let you know if I find anything. At this stage, I'm not overly concerned with the smoke thingy.
Errol.

 

[oigle]

Think I would be looking for a loss of pressurised air from the intake first - split or loose hose or split/damaged intercooler etc.
Secondly I would check the exhaust for blockage in the CATS.

Either can cause black smoke.

Ian.

 

[PC Vehicle Movements]

A quick test to do is block the vacuum pipe off on the EGR if its Vacuum operated if you remove the pipe when the engine is running it will close the egr and the engine will start hunting if the egr closes
if not it may be sticking open
if it does start hunting then block the pipe off with a small bolt or ball bearing and take for a run to see if it has fixed the problem at least you will no if its part of the EGR circuit thats the problem
i had a problem with egr controller thats located under the scuttle it was opening the egr when it should be closed
in the end i blocked the egr off and had it deleted from the ECU

 

[oldgeo68]

Ian,
can't find any trace of leaking hoses etc.....not sure how to check the CAT ...any advice on this ?
Thanks.

 

[allan jenkins]

Think I would be looking for a loss of pressurised air from the intake first - split or loose hose or split/damaged intercooler etc.
Secondly I would check the exhaust for blockage in the CATS.

Either can cause black smoke.

Ian.

I'd have to agree..
I've had 2 split intercooler hoses on both my fiat bravo diesel multyjets.. both lost power and blowing black smoke..
Open the bonnet have someone to rev the engine to see if you can see or hear the split pipe

 

[oigle]

Split hoses are often hard to see. Look for any oil on the hoses - PCV oil will be forced out under pressure through a split. Same with intercooler.
To check a CAT, look for any signs of exhaust leaking around flanges between turbo and 1st CAT. If blocked, the pressure buildup will usually force a leak somewhere.
Your motor would need to be quite old to not have an egr. My 2003 Benz has one and I think they go way back further than that. EGR's are a very common cause of blowing black when they stick partially open.
Ian.

 

[portland_bill]

Black smoke is excess fuel, confirmed by the higher fuel consumption.

As said above, air leaks in the intake system can cause this, especially if after the pressure is sensed, as air loss will not be seen and the fuel injected will be for the expected air.
With the engine running, for all the hoses and connections before the turbo spray something like WD40 over them. Any sucked in will cause the engine note to change, but this small spray amount will not do harm.
After the turbo, same again, but a fine mist water spray will do better. You are looking for it to be pushed back at you.
These tests show any leaks.

Check any tiny hoses too, as there may be some that go to pressure sensors.

You don't say what age, but without EGR I assume it is a mechanical injection setup. The pump and injectors are lubricated by the fuel and ideally need servicing every 80,000 miles or so. The price sounds about right for a specialist overhaul and calibration of pump and injectors if a mechanical system.
You could first try a good dose of injector cleaner in the fuel. Don't add more than the bottle recommends, but you can dose it again sooner rather than later, but ideally leave it two fill-ups between each dose. The injector nozzles have to deliver the fuel as a very fine mist, but are sitting in the combustion chamber, not a friendly environment. Soot can affect the fuel delivery and injector cleaner will help this.

Later common rail systems work much like petrol systems, with a pressure pump keeping a constant pressure and electronic injectors. The pump is not so critical, it just needs to deliver excess pressure and the injectors are usually replaced rather than serviced. Injector cleaner can help them too.

 

[Crossingkeeper]

Just to add that my 2006 2.8JTD motorhome (so probably 2005 build) didn't have a EGR system fitted (I spent a bit of time searching in order to disable it!)

 

[oldgeo68]

Thanks for the input....just to let you know that the fault was a fault in the wastegate actuator connecting rod....basically getting minimal turbo thrust...hence the rich mixture / black smoke. Thanks to mechanic Rowan at North Coast Diesels in Nambour, who picked up after a few km running eu scans that there was minimal thrust, after which he soon found the mechanical problem with the actuator.

 

[oigle]

Thanks for the heads up. Good you found it. Seems your unit must be not reliant on a MAF for air volume measurement. Must be an oldish mechanical injection setup. Very different from the later ones which I assumed you had. Sorry.