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Diesel engine trouble - BMC 1.5


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It sounds like I'm best to do the work myself. Does anyone know the name of the special spanner for the head bolts? I mentioned to the marina that I thought you needed a special spanner and they had told me you don't. I think that shows how little they know about this engine.

 

I think I'll take off the glow plugs and check them out, then take off the rocker cover and measure the valve clearance.

 

Then I guess it's time for taking the head off and dropping it into a specialist for repair.

Its worth a dabble first, if you're checking the valve clearances you could get an idea on the state of the valves by the hissing and resistance you get when turning the engine by hand!

The seats are probably in need of attention, but unless there is a crack or chip in the valves, there is probably no point in taking the head off unless you are planning to look at the cylinders and pistons too?

 

How much does someone like Calcutt charge for an overhaul?

 

The spanner is an 18G694, but don't ask me where to get one from!

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Hi,

 

Thanks for the info.

 

Mine had done about 800 hours before I had to do the work on it.

 

A good, well charged battery turns the engine over more quickly and seems to help it fire up and gets the glow plugs really hot.

 

Exhaust sounds like the system I modified mine to.

 

Gardners do a 'headnut wrench' at £55.10, but I suspect it would be a WW thread and too big overall for your engine.

(Gardner-Enthusiast.com /shop)

 

I could give you the address of the guy in Spain to see if he wants to sell it on (he paid 30Eu for it).

 

But do try the fuel system and battery avenue first - it's a shame these engines do not have a de-compression lever.

 

Also make sure your fuel shut off lever and spring are working well.

 

The part number for the spanner is correct, try Calcutt to see if they have one for sale.

 

Best of luck.

 

Albi

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BMC 1500 workshop manual and that didn't cost no money...

 

Screwfix do a set of metric crows feet item number 80651 a 12mm one could be filed out.

 

AMC diesels certainly used to supply a lot of BMC stuff mail order but Calcutt are just as reputable and closer to you.

 

I think John O's right, if no cylinders are firing I'd strip the fuel side down first, start with getting your injectors serviced.

 

Did you mean 1500 hours or 15000, my isuzu did 1500 hours in 18 months...

 

edit: I've got loads of Marine 16. If you've an excuse to pass Brum you're welcome to some of it.

Edited by Smelly
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I have checked the glow plugs. They are getting voltage and I also checked them all with a multimeter. I replaced one (the one on the cylinder they say has low compression). The only thing I did notice was the voltage was around 10 volts and not 12 (tested between the engine earth and the main feed for the glowplugs). The battery had 12.6 volts.

 

I'll try the oil in the air intake next time I'm at the boat (it's a bit of a drive from home). I guess you are talking of putting normal engine oil in the air intake? And this seals the pistons or something?

 

One other thought, the cylinder with low compression is the same one as I changed the glowplug. I'm presuming they put the compression gauge on the glowplug hole? Or is it on the injector hole? I'm just wondering if the glowplug might not be tight enough?

 

OK, so are they getting hot? And the 10V - this is not right, glow plugs should not drag your battery voltage down so much, check the voltage at the battery and at the switch end of the glow plug cable when they are switched on, if different then there is a problem in the wiring, glow plugs are quite high current so dodgy connections count.

 

I still suspect fuel contamination, the fact that this was one of your original problems. It can be quite difficult sometimes to clear fuel lines and often takes a few clean out sessions.

 

Do you have a drain on the fuel filter - this is the usual place to check fuel contamination as water sinks to the bottom.

 

Yes, to engine oil, it seals the rings temporarily, enough to get the engine to fire, don't use too much otherwise it's quite likely you'll get a face full as the engine spits it back out the air intake.

 

Whereas taking a cylinder head off is a lot easier than putting it back on again, this is the way to learn but you are definitely not at this stage yet. Your engine needs servicing but I wouldn't go any further yet.

 

If at all possible get the engine serviced by a competent diesel mechanic, getting someone in and arguing the toss afterwards seems to be the way to go.

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The marina have seen my post on another forum and are annoyed that I don't trust their judgement. I had a bit or an argument with them as I said the gearbox job had ended up costing £1200 more than they quoted.

 

 

Anyway I found out the injectors are out of the engine, so would be easy to test. Also the cylinder with poor compression is one in which I replaced the glow plug. I couldn't get the glow plug to screw in as far as the old one. So there might be a chance that is causing low compression. But they say the others being at 200 to 240 PSI means the engine is dead.

 

 

To be honest I'm considering selling the boat, I just don't have much money to spend on it. The marina insist the only way forward is a new engine and still claim Easy Strart did the damage.

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The marina have seen my post on another forum and are annoyed that I don't trust their judgement. I had a bit or an argument with them as I said the gearbox job had ended up costing £1200 more than they quoted.

 

 

Anyway I found out the injectors are out of the engine, so would be easy to test. Also the cylinder with poor compression is one in which I replaced the glow plug. I couldn't get the glow plug to screw in as far as the old one. So there might be a chance that is causing low compression. But they say the others being at 200 to 240 PSI means the engine is dead.

 

 

To be honest I'm considering selling the boat, I just don't have much money to spend on it. The marina insist the only way forward is a new engine and still claim Easy Strart did the damage.

 

If they are cross that you don't trust them, then it shows they aren't trustworthy!

 

If you bleed the engine when it has started, and doesn't start in the morning, does it start?

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If you bleed the engine when it has started, and doesn't start in the morning, does it start?

 

It won't start at all after bleeding it. Since having this problem I have only managed to get it running on one occasion after using Easystart. It then run fine if switched off for a short while, but became progressively more difficult to start the longer it was left. By the next day it wouldn't start at all (but didn't try Easystart again).

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Also the cylinder with poor compression is one in which I replaced the glow plug. I couldn't get the glow plug to screw in as far as the old one. So there might be a chance that is causing low compression.

 

If you haven't screwed the glow plug in far enough to make a seal, then that will lower the compression as the gasses will leak out. Your marine engineer should spot that.

 

Richard

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I thought that to compression test an engine, the tester is fitted into the heater plug socket.

 

So if that was fitted correctly, then it would show the 'correct' pressures.

 

This engine apparently has one cylinder compression that is not the same/close to the other three but I would have thought that it would still run (not correctly but still run).

 

Start with the basics:

 

1. is the fuel up to standard (no water)

 

2. are the heater plugs working correctly

 

3. is there fuel at the injectors

 

4. are the injectors clean

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I thought that to compression test an engine, the tester is fitted into the heater plug socket.

 

So if that was fitted correctly, then it would show the 'correct' pressures.

 

If that is the case, then I stand corrected.

 

As many people have said, please can you check the basics first - fuel at the injectorsclean dry and air free, heater plugs OK.

 

Richard

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If that is the case, then I stand corrected.

 

As many people have said, please can you check the basics first - fuel at the injectorsclean dry and air free, heater plugs OK.

 

Richard

 

 

The compression test was done by removing the injectors, not the glow plugs.

AFAIK they have not tested fuel at the injectors, all they did was the compression test. Now the injectors are off they will be easy to test.

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Also the cylinder with poor compression is one in which I replaced the glow plug. I couldn't get the glow plug to screw in as far as the old one. So there might be a chance that is causing low compression.

Assuming the compression test is done throug the injector, rather than the heater holes, (I'm sure the experts will tell us)..........

 

It does sound worrying that the cylinder you may not have fully sealed a heater plug in to has appreciably lower compression than the rest.

 

When you did have the engine running, was it fully firing on 4 cylinders, or is there a possibilty that it was never firing on more than 3, (which would sound very rough, compared to normal running).

 

If there is any danger at all of a leak around the heater plug, it will clearly be going a long way to make an engine already reluctant to start, even less likely to do so.

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Hi,

 

Still no further forward.

 

Although the engine has 'only' done 1500 hrs since 1975 there is every chance that it dates from the early 1960's and was taken from a scrapped vehicle about 1975. The degree of overhaul and marinisation was probably minimal. So one could be talking about a fairly old engine here. A friend did this with a boat he had built by Charlie Fox in 1975.

 

It probably needs the injectors to be removed and serviced, something which may not have been done over the years and which is not a big or expensive job.

 

Be careful removing the glow plugs as it is easy to snap these off and then it's c/head removal for sure and carefully tighten up the one you removed.

 

Initially 'my' 1.5 was very temperamental and work on the c/head including servicing the injectors made it much more reliable.

 

If you are getting fuel up to the union with the injectors by bleeding, it would suggest a problem with them.

 

Best of luck, sorry to hear of the attitude of the mechanics, it's not doubting their ability but seeking alternatives before parting with the 'boodle'

 

Mike

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Once upon a time a mechanic would not be able to resist fixing your heater plug problem whilst doing the preasure test. It seems modern people are too mad or greedy to do that. I deduce that your mechanics could have had a similar result to you and that heater plug when screwing stuff into your head, so you may just have to clean out all the holes realy well and replace all the washers. Check the timing on the pump as well, you may have an alignment mark scribed on it to help.

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Anyway I found out the injectors are out of the engine, so would be easy to test. Also the cylinder with poor compression is one in which I replaced the glow plug. I couldn't get the glow plug to screw in as far as the old one. So there might be a chance that is causing low compression. But they say the others being at 200 to 240 PSI means the engine is dead.

This is probably caused by sooting - the carbon fills the gap between the block and the plug tip. The heater plug holes can be cleaned out carefully using a 3.5mm drill (use a manual brace or twist drill) - you have to make sure you only remove carbin and not metal as this is going into the cylinders!

This will improve the heater plugs effectiveness, so if you do it, check all four cylinders.

 

Loose heater plugs can affect the engine, I had one work loose on a 1.8, and although the engine started to behave a bit odd, I did not panic until diesel started coming out of the exhaust!

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This is probably caused by sooting - the carbon fills the gap between the block and the plug tip. The heater plug holes can be cleaned out carefully using a 3.5mm drill (use a manual brace or twist drill) - you have to make sure you only remove carbin and not metal as this is going into the cylinders!

This will improve the heater plugs effectiveness, so if you do it, check all four cylinders.

 

Loose heater plugs can affect the engine, I had one work loose on a 1.8, and although the engine started to behave a bit odd, I did not panic until diesel started coming out of the exhaust!

 

Although likely you have problems elsewhere, do not overlook this advice. Twice since owning my boat two and a half years ago it has consistently failed to start without easystart. Twice I have remedied it to start perfectly by clearing this carbon blockage. I can only get the drill bit in if held and twisted by finger and thumb, but the advantage is you can feel the blockage, and feel when you've broken through it.

 

And i'd classify my engine as tired, probably as evidenced by needing to repeat this 'de-coking' procedure in a relatively short space of time.

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Twice since owning my boat two and a half years ago it has consistently failed to start without easystart. Twice I have remedied it to start perfectly by clearing this carbon blockage. I can only get the drill bit in if held and twisted by finger and thumb, but the advantage is you can feel the blockage, and feel when you've broken through it.

The recent thread on fuel catalyst got me thinking a bit!

Catalysts often work in a number of ways (both chemical and mechanical), their effect often to produce an increase in one component of whats passing across them. With fuel the likelyhood is that it creates a more uniform consitency of medium chain molecules (and may also remove comtaminants) which could lead to a lower auto ignition temperature and better combustion?

Diesel engines work by compression the air (typically more than 20 times) and this produces heat enabling the diesel injected to reach its auto ignition temperature (around 200C).

A newer engine with good compression can proably do this easily without any external heat!

As wear increases and compression reduces or outside temperature drops (winter), chances are that this can only be achieved at start up with external heat (use of heater plugs). Once warm (say 90C) the engine can keep firing.

This probably means that the older and more tired the engine, the more important the heater plugs and their correct function become?

Carbon will build up around the tip of a heater plug, making the heat dissipate into the head rather than heating the air. It is the temperature of the air that needs to be increased, occupying a very small space after compression, as opposed to the large lump of metal (engine) which the heater plug is not powerful enough to raise the temperature of (much)!

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  • 12 years later...

Hello, I have been looking into this forum recently, sinse I also have black slim and soot on the water after starting the engine, which takes a long time of cranking.
I took out the glowplugs and cleaned out the carbon. I would recommend doing this at least every 3-4 years. I am now waiting for a new pair of blugs coming from the uk. I am confident the engine will start better. I believe the black stuff throwen out at start has to do with the fuel system and adjustments and the not burnt fuel in the chambor? Maybe someone knows more?
About Easy Start. You could also take a tourch and hold it into the air intake. Then just crank the engine over as long as the battery allows.
For a basic injector check (to see if they spray) take off the injector holders with injector and crank. By doing this with all 4 you should see if the spray pattern is simular, which does not mean that it is right. Another way to see if the pattern is simular could be to crank the engine over when the glowplugs are out and the carbon is cleaned out. You see how much spray comes out of the glowplug holes. Give a bit of troddel and see if it gets more.
No spray, bad injectors.
Water and dampness are injector killers by standing engines. I overhauld my bmc 1.5 in a damp basement for 5 years. I thought it would go quicker and put in the new injectors in the first year. They had not seen any diesel, so they were not lubricated. After 5 years they were shot by dampness.
I understand yours might have gotten some waterfuel? Check out the injectors.
200 psi is not great, but if you get them running it may last until you find a good engine, maybe in a different boatyard.
Another thing, as Bizzard often says. Check the valve clearing.
All the best
Douglas

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Suggest you buy a diesel compression tester (not a petrol one,they won't register high enough)

Pour some oil in the cylinder through the heater plug hole or bleed it in through the air intake and spin the engine over and check the compression yourself.

If the compression is greater with the oil in than without,then it indicates bore/piston ring wear. If the compression is the same then that would point to leaking valves.

There is a BMC manual online,which would be a good idea to access.

From what you have said about the people who have worked on your engine and the stupid comment about Easystart,I wouldn't trust them to fit a chain on a pushbike.

As you are not allowed by your mooring agreement to bring in Your choice of mechanic,they have you by the short and curlys.If you take your boat elswhere to have it fixed,you might be told to moor elsewhere.Sounds as though they wear a three cornered hat and sport a brace of pistols!

Hope it is something you can fix yourself.

 

Edited by Mad Harold
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