Black Oily Substance (Assumed To Be Diesel) Intermittently Leaking From Exhaust.

[alan_fincher]

I'm starting another thread on this, as the previous one lost direction somewhat, and I'm still looking for ideas......

 

Chalice is intermittently leaking a black oily film from it's exhaust pipe. This only happens infrequently, and cannot clearly be linked to any particular pattern of use, how long the engine has run, or how hard it is being, (or has been being), worked.

 

Although a film can be seen down the side of the counter, it's only rarely that it gets bad enough to put a significant slick on the water, but occasionally it will do this to the extent of going into the "embarrassing" category.

 

At one point we tied up, and the "slick" was spread for several yards backwards behind the boat.

 

Despite people previously saying it would only be diesel if it smelt of diesel, I have to think it is, even if I, at least, can smell no diesel at all if I collect some on a rag, and sniff it.

 

If you drop engine oil into water it sits on the surface in "blobs", and does not spread at all. This deposit instead spreads very quickly, giving the typical rainbow effect of spilt fuel. It's very hard to see how it is anything other than fuel based, as engine oil just can't be made to spread like that.

 

So, if I'm right, and it's unburnt fuel, how is it getting there. Well of course it can only be via the injectors, can it ?

 

These were swapped out for some serviced exchange ones shortly before we had the head gasket done, and a cracked head replaced. The guy that did them seems to have a good reputation locally, and to have been used by several forum members.

 

So, for the uninitiated, what could be wrong with them ? What would cause them to pass un-atomised fuel that then gets ejected at least not fully burnt ?

 

If I go back to the diesel injection specialist, how much can they retest without dis-assembling them, and what can only be checked out by taking them to pieces again.

 

I should add that many agreed we needed to use the boat further under mixed conditions - we have just come back from a 120 mile 130 lock trip, including thrashing 16 miles up the tidal Thames. The engine has not missed a beat in that time, and had we not got this deposit from the exhaust, I would have declared it to be in a good state.

 

However this has the potential to cause enough minor pollution that I am completely unhappy to do anything other than keep working at it until we can correct whatever is causing it.

 

So, further thoughts, anybody ?

 

Alan

[NB Alnwick]

I'm starting another thread on this, as the previous one lost direction somewhat, and I'm still looking for ideas......

 

Chalice is intermittently leaking a black oily film from it's exhaust pipe. This only happens infrequently, and cannot clearly be linked to any particular pattern of use, how long the engine has run, or how hard it is being, (or has been being), worked.

 

Although a film can be seen down the side of the counter, it's only rarely that it gets bad enough to put a significant slick on the water, but occasionally it will do this to the extent of going into the "embarrassing" category.

 

At one point we tied up, and the "slick" was spread for several yards backwards behind the boat.

 

Despite people previously saying it would only be diesel if it smelt of diesel, I have to think it is, even if I, at least, can smell no diesel at all if I collect some on a rag, and sniff it.

 

If you drop engine oil into water it sits on the surface in "blobs", and does not spread at all. This deposit instead spreads very quickly, giving the typical rainbow effect of spilt fuel. It's very hard to see how it is anything other than fuel based, as engine oil just can't be made to spread like that.

 

So, if I'm right, and it's unburnt fuel, how is it getting there. Well of course it can only be via the injectors, can it ?

 

These were swapped out for some serviced exchange ones shortly before we had the head gasket done, and a cracked head replaced. The guy that did them seems to have a good reputation locally, and to have been used by several forum members.

 

So, for the uninitiated, what could be wrong with them ? What would cause them to pass un-atomised fuel that then gets ejected at least not fully burnt ?

 

If I go back to the diesel injection specialist, how much can they retest without dis-assembling them, and what can only be checked out by taking them to pieces again.

 

I should add that many agreed we needed to use the boat further under mixed conditions - we have just come back from a 120 mile 130 lock trip, including thrashing 16 miles up the tidal Thames. The engine has not missed a beat in that time, and had we not got this deposit from the exhaust, I would have declared it to be in a good state.

 

However this has the potential to cause enough minor pollution that I am completely unhappy to do anything other than keep working at it until we can correct whatever is causing it.

 

So, further thoughts, anybody ?

 

Alan

 

Probably time to get the injectors serviced and make sure you do not have any blockages or restrictions in the high pressure fuel lines. We had a similar problem with our engine except that with a vertical exhaust the unburned fuel/oil was deposited on the roof and on the steerer's head! We had the injectors and injection pump serviced, re-set the injection timing to the factory mark and brought in an expert to re-solder a faulty high pressure fuel line - problem solved! If the injectors are performing efficiently, the contents of the combustion chamber (including any lubricating oil that has seeped down the valve guides and up the cylinder bores) will be consumed completely. I don't think there is that much difference between a classic Kelvin and a classic BMC in this respect.

Edited June 9, 2010 by NB Alnwick

[alan_fincher]

Probably time to get the injectors serviced...........

Well that's what we did have done, before all this started.....

 

Or more accurately he exchanged them, and we got someone else's serviced and tested set back.....

 

I intend to have a chat with the guy, but before I do, I'm keen to understand as much as I can about what fault (presumably) one of them may have, and what I need to try and negotiate for him to specifically test for, if I do take them back to him.

 

As I said this s the chap who several in the area have recommended as being good, but what do I know ?

[Albion]

snipped

 

If I go back to the diesel injection specialist, how much can they retest without dis-assembling them, and what can only be checked out by taking them to pieces again.

 

Alan

 

The injectors can be fully tested without dismantling. Basically they are checking for cracking pressure and spray pattern. If these two things are OK then there is absolutely no need to dismantle.

Roger

[Naughty Cal]

Faulty stern drive trim ram?

 

Ok maybe not but i know how you feel about your slick if it is any consolation

[alan_fincher]

The injectors can be fully tested without dismantling. Basically they are checking for cracking pressure and spray pattern. If these two things are OK then there is absolutely no need to dismantle.

Roger

Thanks, exactly what I needed to hear.

 

Of course my doubts are that if it's intermittent on the boat, and they are behaving ninety-something percent of the time, that they will also do so if "diesel injection man" re-tests them.....

[Albion]

Thanks, exactly what I needed to hear.

 

Of course my doubts are that if it's intermittent on the boat, and they are behaving ninety-something percent of the time, that they will also do so if "diesel injection man" re-tests them.....

 

Using exchange injectors rather than rebuilding your own is perfectly standard practice by the way in the trade.

 

Your injectors are a very basic mechanical pressure operated valve (put crudely) and should either work correctly or not. It is very unlikely that they would be intermittent. If you were talking solenoid operated petrol injection injectors or piezo-electric diesel common rail injectors then it might be a different matter.

Roger

[RobinJ]

Chalice is intermittently leaking a black oily film from it's exhaust pipe. This only happens infrequently, and cannot clearly be linked to any particular pattern of use, how long the engine has run, or how hard it is being, (or has been being), worked.

Although a film can be seen down the side of the counter, it's only rarely that it gets bad enough to put a significant slick on the water, but occasionally it will do this to the extent of going into the "embarrassing" category.

At one point we tied up, and the "slick" was spread for several yards backwards behind the boat.

Despite people previously saying it would only be diesel if it smelt of diesel, I have to think it is, even if I, at least, can smell no diesel at all if I collect some on a rag, and sniff it.

If you drop engine oil into water it sits on the surface in "blobs", and does not spread at all. This deposit instead spreads very quickly, giving the typical rainbow effect of spilt fuel. It's very hard to see how it is anything other than fuel based, as engine oil just can't be made to spread like that.

So, if I'm right, and it's unburnt fuel, how is it getting there. Well of course it can only be via the injectors, can it ?

Lighter engine oils do create a similar pattern when dropped in water, but it does not spread as quickly and because generlaly thicker has less of a colour spectrum!

These were swapped out for some serviced exchange ones shortly before we had the head gasket done, and a cracked head replaced. The guy that did them seems to have a good reputation locally, and to have been used by several forum members.

So, for the uninitiated, what could be wrong with them ? What would cause them to pass un-atomised fuel that then gets ejected at least not fully burnt ?

If I go back to the diesel injection specialist, how much can they retest without dis-assembling them, and what can only be checked out by taking them to pieces again.

I should add that many agreed we needed to use the boat further under mixed conditions - we have just come back from a 120 mile 130 lock trip, including thrashing 16 miles up the tidal Thames. The engine has not missed a beat in that time, and had we not got this deposit from the exhaust, I would have declared it to be in a good state.

However this has the potential to cause enough minor pollution that I am completely unhappy to do anything other than keep working at it until we can correct whatever is causing it.

Not necessarily an injector problem, their job is to put diesel into the cylinder at the right time and in the right quantity, its what happens next that is likely the problem! Unless of course the injector pipes were swapped over, but then it should be running really badly if at all!

I would possibly try and get a compression test done, that might help determine the cause.

With a leaky exhaust valve, you could be loosing compression, getting poor combustion and diesel could be leaking into the exhaust.

If an inlet valve was not operating correctly I suppose it could be possible not to get enough air, but I think the exhaust is more likely.

My experience (with the lump of metal under the cam opening the exhaust) resulted in an intermittent misfire, but that was sufficient to throw quite a significant amount of fuel out of the exhaust after only a short time.

You may have to check the valve clearances, look at the valve seats or make sure they are not sticking because of gummy valve guides or broken springs?

[alan_fincher]

Lighter engine oils do create a similar pattern when dropped in water, but it does not spread as quickly and because generlaly thicker has less of a colour spectrum!

I'm using a 20W/50 oil, and when i test dropped a couple of drops of that into water they remained as a droplet shape on the wtaer surface, and didn't disperse at all. I am now convinced, despite not smelling like diesel, that it has to be diesel.

[GSer]

There's no possibility it could just be condensation washing oily soot from the exhaust?

[RLWP]

Alan, could you provide a link to your previous thread here please to avoid us going over old ground again?

 

Richard

[RobinJ]

Alan, could you provide a link to your previous thread here please to avoid us going over old ground again?

Previous Thread

I think that was the one!

[Naughty Cal]

Alan, could you provide a link to your previous thread here please to avoid us going over old ground again?

 

Richard

 

That could be where the problem lies, boats should be in water

[paulcatchpole]

That could be where the problem lies, boats should be in water

 

:lol:

 

I still think it's schlobber...

 

PC

[alan_fincher]

:lol:

 

I still think it's schlobber...

 

PC

Yes,

 

Someone else has said the same in a PM, but they say that when analysed slobber is still basically unburned diesel.

 

So I need to stop it slobbering, it seems.....

 

.......(possibly!).

 

EDITED TO ADD:

 

So what causes slobber, and how do I fix it!

Edited June 9, 2010 by alan_fincher

[paulcatchpole]

Yes,

 

Someone else has said the same in a PM, but they say that when analysed slobber is still basically unburned diesel.

 

So I need to stop it slobbering, it seems.....

 

.......(possibly!).

 

Well, it's a good question how to stop it!

 

Sorry Alan, identification: win, solution: fail.

 

On t'other hand, is slobber a bit like this chap:

 

 

PC

[David]

Hi

One other item not mentioned is were your exchange injectors fitted with the correct angle of spray pintels, the wrong angle ones spray the fuel not into the combustion chamber but against the walls this can result in incomlete burnt fuel, maybe that is where the excess fuel is originating, if that it is what it is.

My friend has again had to get the correct ones fitted in a clients injectors on the engine we just finished working on despite the engine having been fitted with "newly fully serviced injectors" this by no means the first ones he has found fitted with the wrong ones, possibly because they are of a common or more easily available type.

david

[RLWP]

<snip>

On t'other hand, is slobber a bit like this chap:

 

 

PC

 

No, that's a flubber.

 

You can't fool me you know

 

Richard

 

Hi

One other item not mentioned is were your exchange injectors fitted with the correct angle of spray pintels, the wrong angle ones spray the fuel not into the combustion chamber but against the walls this can result in incomlete burnt fuel, maybe that is where the excess fuel is originating, if that it is what it is.

My friend has again had to get the correct ones fitted in a clients injectors on the engine we just finished working on despite the engine having been fitted with "newly fully serviced injectors" this by no means the first ones he has found fitted with the wrong ones, possibly because they are of a common or more easily available type.

david

 

So why isn't this blasted engine pouring unburnt fuel and smoke out all the time then? It's the highly intermittent and actually quite small nature of Alan's problem that makes it so frustrating.

 

Richard

[alan_fincher]

So why isn't this blasted engine pouring unburnt fuel and smoke out all the time then?

Just to be clear, there is no issue with excessive smoke.

 

Even when it's producing the "glopp" at the exhaust, there is no smoke to speak of.

 

I can't understand if any of the injectors has wrong parts or assembly, why the problem is not more continuous.

 

We can't establish any obvious pattern to when it starts, (or ends).

[GSer]

There's no possibility it could just be condensation washing oily soot from the exhaust?

 

 

Bumped just to repeat the question?

 

 

 

On the thames, when moored up, the wash from passing boats can flood the exhaust washing the inside and moving fair amounts of oily soot, although i suppose if your exhaust is on the roof thats not going to happen unless your having a real bad day

[Tony Brooks]

Hi

One other item not mentioned is were your exchange injectors fitted with the correct angle of spray pintels, the wrong angle ones spray the fuel not into the combustion chamber but against the walls this can result in incomlete burnt fuel, maybe that is where the excess fuel is originating, if that it is what it is.

My friend has again had to get the correct ones fitted in a clients injectors on the engine we just finished working on despite the engine having been fitted with "newly fully serviced injectors" this by no means the first ones he has found fitted with the wrong ones, possibly because they are of a common or more easily available type.

david

 

 

1.5s use Pintaux nozzles which are a derivative of ordinary pintle ones and I have never seen a pintle type nozzle that does anything but spray a hollow cone straight out of the end. Multi-hole nozzles often have to be fitted in the correct alignment and there are unusually pins in the body to ensure they are. I suspect single hole nozzles could also be made with an angled spray but I fail to see how a pintle one can be made that way.

 

The pintaux nozzle has a pintle type main spray but also an exceptionally small hole pointing out from the side of a small bump that surrounds the pintle. These direct fuel, during cranking, towards the hottest part of the pre-combustion chamber (presumably the glowplug) to aid cold starting and should hardly spray at higher speeds. They do block up and I suspect it is this that makes some BMCs interesting to cold start. The body on pintaux injectors should have location pins but as the bodies are identical to many ordinary pintle injectors it would be easy to forget you were dealing with a pintaux injector and fail to fit the pins. However because the auxiliary spray hole is most effective during cranking I am having difficulty believing its misalignment is the problem unless the cold starting is also a bit more difficult. But then anything is possible.

 

Under the nozzle of 1.5 injectors is a little steel washer with a sort of crimped upstand around it. In my day they were called atomisation washers but today they seem to call them heat shields. I wonder if they are in place and were renewed with the injectors. the old ones can be a right pig to get out so there may be two down some holes. I think it must be time to get those injectors out and to a local specialist for testing. Once they are out those washers could be checked. They do make a difference to the running of the engine.

[RobinJ]

Just to be clear, there is no issue with excessive smoke.

Even when it's producing the "glopp" at the exhaust, there is no smoke to speak of.

I can't understand if any of the injectors has wrong parts or assembly, why the problem is not more continuous.

We can't establish any obvious pattern to when it starts, (or ends).

Ah! precisely. If there is a sticking valve, it might stick or not (depending on how it feels), so gloop only now and then, (when its cold, wet, Tuesday afternoon?) taking a while to work its way through to the canal!

With mine, because the metal lump was floating through the cam on every other'ish alternate rotation, almost every other stroke produced some diesel, so was quite runny?

[alan_fincher]

There's no possibility it could just be condensation washing oily soot from the exhaust?

 

Bumped just to repeat the question?

 

On the thames, when moored up, the wash from passing boats can flood the exhaust washing the inside and moving fair amounts of oily soot, although i suppose if your exhaust is on the roof thats not going to happen unless your having a real bad day

Sorry, no, I don't think so.

 

I'm now over 90% certain it's diesel based.

 

Whatever the cause it was not happening before we replaced the injectors with exchange ones, then had the head gasket replaced, which expanded to a replacement second-hand head, after ours was found to be cracked in several places.

 

Unfortunately the boat received very little use between these two events, so at least 3 things have changed....

 

1) Injectors

2) Head gasket

3) Complete head

 

and it's therefore not easy to assess which of these three things has caused it.

 

As I say, it never had this symptom before, and I'm largely convinced that unburned diesel is now intermittently passing through.

 

I keep meaning to make an estimate of recent consumption, to see if it differs wildly from previous use, but as it includes the tidal Thames, and a thrash down the Paddington Arm, it may not be represenatative anyway.

[alan_fincher]

1.5s use Pintaux nozzles which are a derivative of ordinary pintle ones and I have never seen a pintle type nozzle that does anything but spray a hollow cone straight out of the end. Multi-hole nozzles often have to be fitted in the correct alignment and there are unusually pins in the body to ensure they are. I suspect single hole nozzles could also be made with an angled spray but I fail to see how a pintle one can be made that way.

 

The pintaux nozzle has a pintle type main spray but also an exceptionally small hole pointing out from the side of a small bump that surrounds the pintle. These direct fuel, during cranking, towards the hottest part of the pre-combustion chamber (presumably the glowplug) to aid cold starting and should hardly spray at higher speeds. They do block up and I suspect it is this that makes some BMCs interesting to cold start. The body on pintaux injectors should have location pins but as the bodies are identical to many ordinary pintle injectors it would be easy to forget you were dealing with a pintaux injector and fail to fit the pins. However because the auxiliary spray hole is most effective during cranking I am having difficulty believing its misalignment is the problem unless the cold starting is also a bit more difficult. But then anything is possible.

 

Under the nozzle of 1.5 injectors is a little steel washer with a sort of crimped upstand around it. In my day they were called atomisation washers but today they seem to call them heat shields. I wonder if they are in place and were renewed with the injectors. the old ones can be a right pig to get out so there may be two down some holes. I think it must be time to get those injectors out and to a local specialist for testing. Once they are out those washers could be checked. They do make a difference to the running of the engine.

This is a 1.8, Tony, but I don't think that changes any of your remarks, does it ?

 

This mobile engineer rather specialises in older run-of-the-mill engines like BMCs, and I'd be surprised if there was not one (and only one) "atomisation washer"/"heat shield" per injector - though you never know! Where he may have cut corners is in reusing, rather than replacing these. As I understand it you should always use a new one, and that is what I had done a month or so previously when the injectors were swapped out. (Incidentally I had no trouble whatsoever in removing the old - a "Bic" type biro case pushed in brought each out as soon as it was removed).

 

My only reluctance to have them out again is that the injector pipe unions themselves show slight seepage of fuel, and it seems harder to eliminate this each time the nuts on the unions are disturbed. (It seems ready made BMC injector pipes are now hard to acquire, so any replacement would have to be made to order, I suspect).

 

I'm strongly hoping this is an injector fault, as that's something I can do myself, whereas I'm not "tooled up" enough to take the head off, and start looking for valve faults.

 

The engineer involved has broken his leg, and not currently working, so I'm struggling to find anyone else to help on the bits I don't feel confident with.

 

 

 

 

Ah! precisely. If there is a sticking valve, it might stick or not (depending on how it feels), so gloop only now and then, (when its cold, wet, Tuesday afternoon?) taking a while to work its way through to the canal!

I suspect this is part of the problem in diagnosis.

 

It doesn't come out of the hole, at the same time the fault is occurring.

 

With the worst slick we saw, we had been tied up a while, with the engine stopped.

[David Schweizer]

Sorry, no, I don't think so.

 

I'm now over 90% certain it's diesel based.

Whatever the cause it was not happening before we replaced the injectors with exchange ones, then had the head gasket replaced, which expanded to a replacement second-hand head, after ours was found to be cracked in several places.

 

Unfortunately the boat received very little use between these two events, so at least 3 things have changed....

 

1) Injectors

2) Head gasket

3) Complete head

 

and it's therefore not easy to assess which of these three things has caused it.

 

As I say, it never had this symptom before, and I'm largely convinced that unburned diesel is now intermittently passing through.

 

I keep meaning to make an estimate of recent consumption, to see if it differs wildly from previous use, but as it includes the tidal Thames, and a thrash down the Paddington Arm, it may not be represenatative anyway.

The trouble is that you are too nice a chap to make a fuss. My advice is to take the boat back to the chap who fitted the head and injectiors and tell him to sort it out.

 

I doubt whether you would accept your car not functioning properly after it had been serviced, so why be more cautious about a marine engineer?