Hi Everyone

After leaving my pride and joy untouched over the last 4 months, I finally managed to wangle a half-day and got to her Friday. Started (after very little persuasion), but is belching very white smoke. It was always a fairly smoky engine from the day we bought it in 2002, but having got it completely overhauled in 2004 it worked great for a number of years, but it looks like there's a bit of a problem again.

Can anyone suggest whether there are any quick tests or checks I can do to identify what may be the problem, or ideally someone make a recommendation to fix it ? I'm not particularly mechanically-minded, but always ready to have a go...

Engine is a 40-y-o BMC, about 1.6 I think, 28hp or thereabouts, and revs at about 700 on idle, and cruises happily at about 1700. Anything harder is wasted energy. Funnily enough, the smoke seems worst when the engine is NOT being revved hard. Does that make any sense ? Does it suggest a poorly firing cylinder ?

All help and advice gratefully received

Cathal

My thanks to United Diesel Injection Services for the synopsis below
'The Answer is in the Smoke

We can generally understand what is wrong with a diesel engine by the colour of smoke emitted from the exhaust. There are three basic colours - black, white and blue.
Black Smoke

This is due to a air to fuel ratio imbalance, either the fuel system is delivering too much fuel into the engine or there is not enough clean air (oxygen ) a few things to look for :

Faulty injectors (injectors need attention at about 100.000 to 120 000 miles)
Faulty injector pump
Dirty air cleaner
Turbocharger or intercooler faulty
Problems within cylinder head, valves clogged up due to faulty EGR (exhaust gas recycling unit)

White Smoke

Normally means that the fuel injected into the cylinder is not burning correctly. The smoke will burn your eyes.

Engine/pump timing out
Fuel starvation to the pump causing the pumps timing not to operate correctly
Low engine compression
Water/petrol in the fuel

Blue Smoke

The engine is burning engine oil

Worn cylinders or piston rings
Faulty valves or valve stem seals
Engine over full with engine oil
Faulty injector pump/lift pump allowing engine oil to be mixed with the diesel'

So since she was fine at the end of last year the only possibility (maybe!) is that a bit of water has got mixed in the fuel.

Maybe check the water trap if there is water there would support Alun's theory?


John

New pope ?



On 27 February 2012 11:43, IWAI forum John.Kinsella1 wrote:

> Posted at: [www.iwai.ie]
> John.Kinsella1 wrote:
>
> Maybe check the water trap if there is water there would support Alun's
> theory?
>
>
> John
>

Reply Quote

Don't forget that it could be just steam! This time of year can get confusing when starting your engines.

For example, when i'm on the plane in the winter, I don't see anything rising off the stern, however in winter there is always steam and it looks as though something is wrong, when infact it's just the cold air

I assume from your description that your engine is a BMC 1500cc Diesel. These are an indirect injection unit, and are prone to carbonise the exhaust ports heavily especially so in examples that are allowed to run slowly for continuous periods. If the atomisers are not maintained in tip top order on these engines, carbonisation can occur prematurely. Also, the cooling system must be in good order with a working thermostat keeping the temperature up at approx 80 degrees at least. You mention the engine being hard to start. These engines are fitted with individual heater probes into each precombustion chamber. Early versions are fitted with 9volt heater probes wired through a ballast resistor/relay system, with the relay bypassing the ballast resistor when the ignition switch is turned to "crank" position. It is impossible to purchase these 9volt probes anymore and many owners have fitted the only available 12volt versions that you can get today without reconfiguring the associated wiring, resulting in a preheating arrangement that is less than satisfactory. Additionally and most importantly you need to check with whoever does your servicing on this unit, are the heater probes routinely removed and their orfices cleaned out at least once per season. It is essential that this is done as the airgap surrounding the fitted probe is so miniscule on this engine (an acknowledged design fault today) that it quickly becomes clogged with carbon causing the heater probe to heat the carbon and not the air within the precombustion chamber, thus leading to difficult starting. Beware as well, if the heater probes have not recently been removed, there is a very good chance that in trying to remove the units, you will discover that they shear off the tips in situ, leading to a "head off" situation in order to effect a proper repair. The fuel injection pump employed on this engine is the infamous Lucas DPA type, well known for its utter intolerance of even the most miniscule water contamination. The BMC 1500 Diesel has in my opinion aquired an unfair reputation as in inferior unit compared to say a Perkins 4/108 but in my opinion, the major problem with the BMC lies in the owners hands, and whether he/she is willing to keep a proper and thorough service schedule.

Robert,
Do you know if the same applies to 2.2 BMC engine?
Thanks,
Jackie.

Yes Jackie, the 2.2 BMC is also an indirect injection unit, so technically is similiarly afflicted. Carbonisation is a real problem with all indirect diesels. However, in practice, I feel that it is usually the smaller 1500,s that give the most bother, the bother usually is in the form of starting issues. Also, remember what I said about servicing applies no matter what engine you use. Just some engines are slightly more forgiving than others.

Informative and helpful, Thank you. FS

Thanks very much Robert,
Jackie.

On 27 February 2012 22:38, IWAI forum ROBERT McCLEAN wrote:

> Posted at: [www.iwai.ie]
> ROBERT McCLEAN wrote:
>
> Yes Jackie, the 2.2 BMC is also an indirect injection unit, so
> technically is similiarly afflicted. Carbonisation is a real problem with
> all indirect diesels. However, in practice, I feel that it is usually the
> smaller 1500,s that give the most bother, the bother usually is in the
> form of starting issues. Also, remember what I said about servicing
> applies no matter what engine you use. Just some engines are slightly more
> forgiving than others.
>

Reply Quote

Quote:

ROBERT McCLEAN
.

Excellent info Robert! It's a pity I didn't know all this years ago. I used to have a BMC 1500, which, while always reliable, was slow to start. I now know what was probably causing it.

With your permission, can I copy your e-mail to the couple who bought my boat? It would be of great help to them, I'm sure.

regards

Peter.

Peter, absolutely yes, please feel free to pass on this info to anyone whom you feel may benefit.

Thanks Robert - will do

We owe you a debt

Peter

Thank you everyone for the helpful (and in Roberts case incredibly detailed) advice.

I have already checked to see did it indicate a new Pope, but the on-board Pope detector doesn’t work because the Vandals took the handles.

It looks like I need a mechanic. Next step will be to try to find someone with the skills to do the job as described by Robert and the generosity to do it at a reasonable price. Boat is currently in Shannon Harbour, so has anyone a recommendation ? I'll happily travel to anyone worth travelling to !

Thanks again for the help

Cathal