Black smoke on start up

MikeDee

New member
Sprinter '07 311 CDI 2.1litre. First symptom - black smoke on start-up in cold weather. No error codes. Smoke cleared quickly as engine temperature rise. Second symptom: failure to start at all one frosty morning. Started with smoke at lunch time. Took it to Mercedes dealership. They couldn't find a problem, said it started fine, but renewed glow tubes and relay, said if not this system, then must be injectors which they wouldn't touch as these had been refurbished and reinstalled about 6 months previously by an independent. Took it to another independent injector specialist, Bosh agent. Leakdown test OK although lower pressure on both low pressure pump and high pressure pump. They also noticed DPF had been removed (by previous injector refurbishers without my approval after my complaint at loss of power - I subsequently found that wrong codes for injectors had been applied and I had to get Mercedes dealers to recode), but that start up smoke was too much to attribute solely to this. They suggested returning it to original injector refurbishers as injectors were still under 1 year warranty. They also said change battery as seems tired. I DIY charged battery, 12.48 volts on reinstalling, 14.4 volts on idling, 11.7 volts on ignition (first position) and lights on but not yet cranking motor; so thought not battery, maybe starting motor tired but not cause of smoke issue. Third symptom: EGR error code now displaying P0404 - performance, range issues. I DIY removed and cleaned EGR, coated with soot but mechanically seemingly OK. Erased code and took van to previous injector overhaulers . Code reappeared. Smoke now appearing on cold starts throughout the day, not precisely on initial starting but on subsequent gentle revs, engine rough to begin, then settles down, limp home mode comes on after 5 mins driving. Multicoloured black and grey smoke on start up revs now. Injector refurbishers say EGR failure only to blame - I think this is maybe a secondary symptom, not primary cause. I think maybe injector failure, maybe removal of DPF has reduced back pressure on cylinders, maybe reprogramming of ECU to void DPF sensor input has led to problems. What do you guys think?
 

Markthelark

New member
Sounds lime over-fuelling to me , but know idea why. Would assume if DPF removed the ECU may need a tweak. Hopefully someone with far more knowledge will post soon.
 

lindenengineering

Well-known member
Sprinter '07 311 CDI 2.1litre. First symptom - black smoke on start-up in cold weather. No error codes. Smoke cleared quickly as engine temperature rise. Second symptom: failure to start at all one frosty morning. Started with smoke at lunch time. Took it to Mercedes dealership. They couldn't find a problem, said it started fine, but renewed glow tubes and relay, said if not this system, then must be injectors which they wouldn't touch as these had been refurbished and reinstalled about 6 months previously by an independent. Took it to another independent injector specialist, Bosh agent. Leakdown test OK although lower pressure on both low pressure pump and high pressure pump. They also noticed DPF had been removed (by previous injector refurbishers without my approval after my complaint at loss of power - I subsequently found that wrong codes for injectors had been applied and I had to get Mercedes dealers to recode), but that start up smoke was too much to attribute solely to this. They suggested returning it to original injector refurbishers as injectors were still under 1 year warranty. They also said change battery as seems tired. I DIY charged battery, 12.48 volts on reinstalling, 14.4 volts on idling, 11.7 volts on ignition (first position) and lights on but not yet cranking motor; so thought not battery, maybe starting motor tired but not cause of smoke issue. Third symptom: EGR error code now displaying P0404 - performance, range issues. I DIY removed and cleaned EGR, coated with soot but mechanically seemingly OK. Erased code and took van to previous injector overhaulers . Code reappeared. Smoke now appearing on cold starts throughout the day, not precisely on initial starting but on subsequent gentle revs, engine rough to begin, then settles down, limp home mode comes on after 5 mins driving. Multicoloured black and grey smoke on start up revs now. Injector refurbishers say EGR failure only to blame - I think this is maybe a secondary symptom, not primary cause. I think maybe injector failure, maybe removal of DPF has reduced back pressure on cylinders, maybe reprogramming of ECU to void DPF sensor input has led to problems. What do you guys think?
Mike
Based upon your testimony this is what I would be looking at, or be suspicious of to arrive at a diagnosis with possible fix.

1) Cranking speed of the engine is vital for a good clean start especially when cold. For that you need good cold cranking amps from the battery, and a "fit" starter motor which is subject to no significanty "drop" in the wiring harness and good grounds (earths if you are in the UK!)
Suggest some tests on the battery and primary wiring system for starters.
If you have sluggish cranking operation the engine won't fire easily especially when cold, fuel will still be injected and when it does fire. (SMOKE) Fuel lingering in the combustion chambers will emit black and grey smoke as it runs up clearing the cylinders during firing!
I suspect the dealer probably hinted to you something about good cranking requiirements refering to your text!

2) I frankly would be suspicious right from the onset if a customer mentioned re-habbed injectors? Re-worked by who and are they to the correct spec etc etc?
Right of the bat it makes me suspicious and would want to check them for hosing, dribbling and accurate operation. In fact are they installed correctly?

3) Next base line the engine!
The thing will be reluctant to start and burn clean if it doesn't have good compression.
Especially when starting from cold or half cooled condition! The latter give gobs of grey to blue smoke !
Look for cranking pressures or 400psi to 360 psi minimum to light things up.
With a 10% drift on companion cylinders and 25% tops across the cylinders. Although 25% is really pushing it on this engine range

4) Take note that if you have hosing injectors you could quite feasibly be having bore wash which will quickly accelerate cylinder and ring wear; which in turn drops compression and leads to hard starting. The same could be said for poor air filteration.
So an oil analysis is in order; looking for high contents of iron deposits in the oil sample, (accelerated bore wear) silica (bad air filtration) and dilution of oil with fuel (injector faults).
Although not often done by auto and light commercial owners, the heavy vehicle business uses regualr oil sampling as a diagnostic tool to nip potential developing problems in the bud before real issues occur.
As fore the EGR faults if it is getting coated in soot and contamination ther vis a string likelyhood of EGR passages and cooler plugged faults .These should be investigated as part of the EGR problem you are dealing with.
Hope that helps
Regards Dennis
 

MikeDee

New member
Dennis,
Many thanks for detailed response - I'll go through all the points you raise with garage. You've scared me with engine wear - but I haven't been thrashing it since problems first developed - maybe about 400 miles. Also electronic compression test by Bosh agent showed each cylinder in line with others. I'll ask about oil analysis through. Mercedes dealership superficially checked injectors when I got them to recode - what's called a short test in the UK I believe: no problems identified, and they worked fine for about 4 months. So battery, injectors,oil analysis, EGR, and re-instalment of DPF in that order.
 

lindenengineering

Well-known member
Dennis,
Many thanks for detailed response - I'll go through all the points you raise with garage. You've scared me with engine wear - but I haven't been thrashing it since problems first developed - maybe about 400 miles. Also electronic compression test by Bosh agent showed each cylinder in line with others. I'll ask about oil analysis through. Mercedes dealership superficially checked injectors when I got them to recode - what's called a short test in the UK I believe: no problems identified, and they worked fine for about 4 months. So battery, injectors,oil analysis, EGR, and re-instalment of DPF in that order.
Mike
As with all things never rule out a mechanical condition.
All too often in these electronic controlled engines (any engine) , the first thing these days is to immediately condemn a sensor or module, when in fact its something mechanical! On this side its called base lining the engine..
I can't remember what it was called on your side these days but whatever it is it adds up to the same bloody thing!

Now I had a customer recently who had spent a king's ransom trying to fix a starting issue very similar to yours. In fact he had stuck all the key rings from the dealer R/O i/d tags on his ignition key to remind him of all the wasted cash or an exercise in futility I suppose ! Quaint but appropriate in the circumstances. :laughing:
You see when I looked through his repair records only one of the 7 dealers on the West Coast actually did an electronic compression test using a scanner. The rest it seemed fannied around replacing a lot of expensive stuff for no reason!
Now I also do this test (scanner compression test) with the scanner but frankly its only an indication and from my experiences with Benz engines they have to be really huffing and puffing before it will change the reading synchronization (Something like 650 r/m at idle on all cylinders.) Because the scanner relies upon momentary loss of crank speed due to compression as it rolls over TDC and gets kick from the combustion of fuel. Creates a long pulse like wave form if you were to plot it.

With this engine my young very capable tech (a top gun) did the electro test like yours and confirmed "GOOD", but this irascible grey haired old bugger insisted on the old tyme test.
Get Snap On out and test it "propah like", with a gauge/hose screwed into the glow plug hole!

That's where we found it! Compression down on 3 cylinders.
Now I would have expected it to run like ten bob watch from Hong Kong, but it was fine with pressures only in the high 200's. In fact once running with the smoke cleared it ran like "wot" they call over here a Raped Ape! :laughing:

I am not saying that your's will be like that but you need to rule out that area before moving on to other things.

Something else which as struck me since my last post on this was the possibility of a defective CTS Coolant Temp Sensor. Now this should show up on a scan analysis but for some reason the other shop where it had been (E Class 211 platform Diesel) had overlooked the component which was cracked and showing a -40 degrees signal when cold.
Now that was really commanding the FIE system to go "full fuel"' hence the black smoke!
Failed the E test it did!
So you can't rule out anything you just need to be thorough.

If you have more questions I won't be far from a screen.
We have a winter storm warning for the next 48 hours in the Denver Metro area. Twelve (12) inches of snow forecast--Landrover weather!:thumbup:
Cheers Dennis
 
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MikeDee

New member
Dennis,

You've provided more valuable insights: You've talked me into the glow tube compression test; and a definite 'must do' to the Coolant Temp Sensor check. That rings bells 'cus of the temperature sensitive smoke emission profile - although on the down side, surely I'd be getting black smoke out at all start-ups rather than just cold starts after a few hours of non use as at present? (it used to be just overnight starts in low temperature - i.e. around freezing)?

Thanks again,

Mike
 

lindenengineering

Well-known member
Mike
Hi
Just for safety sake why not get an oil sample analysis done.
I so this here with Blackstone Labs:-
http://www.blackstone-labs.com/

On your side I suppose these guys might be the answer:-
http://www.theoillab.co.uk/

The results can be a vital part of preventive maintenance and in the long run save you thousands in unexpected engine failures.

In fact I have one engine in the shop at the moment a 2.7 5 banger that was smoking, not a lot but enough to be a concern. Reluctantly I opened it after a low compression test on one cylinder. I ultimately discovered #4 cylinder was good yet the compression rings were seized. The piston underside had a lot of carbon granules on it--overheating! Perhaps!
After a bit of head scratching I located the issue. Bloody under piston cooling jet was partially blocked, so localized overheat problem.
This led me to ask the operator about oil used.
He wasn't sure his guys bung in the engine what they can find on the road!
And there was his answer--!!!
Again I am not saying this is your case, its just that in so many cases with a Sherlock Holmes approach you can often run down the issue.
By the way I don't suggest for one minute buying a deerstalker hat to do this!
Neighbours might think you have gone bonkers!~:laughing:
Knowing of course that the world thinks us Brits as being a bit eccentric!
But its our national character DNA!:thumbup:
Cheers Dennis
 

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