Hard to Start Diesel

[Guest]

The Bukh engine in my Westerly is hard to start from cold - by which I mean it takes 20/30 seconds of keeping the key turned to get it to chug into life. After the first start it springs into life at the first turn of the key and runs perfectly. It did this last year; it has since been extensively serviced, but is just the same. So - is it me? Is there a best technique for starting an engine from cold?

 

[Guest]

On a diesel car, this normally means the Glow plugs need renewing, can't imagine that it's different on a boat, Unless you are not waiting for the plugs to heat up, Is there a small orange light in the form of a coil in the dash, f so this should come on when you turn on the ignition and then you wait for it to go out before starting the engine. Hope this helps

 

[Guest]

my dv20 was just the same,i fit a cold start kit from bukh.it made a big diferance.

 

[Guest]

Hal

I had the same thing occur with my Yanmar. Last year no problems. Rnd of season - had it serviced and winterised. Back in the water in March and it wouldn't start.

I turned out that a small amount of water had entered the combustion chamber via the exhaust valve from a very very slightly corroded exhaust elbow - at some time or other. As the piston rises to compress the mixture it bends the con-rod very very slightly (as it is also trying to compress the small amount of water. This bend in the con-rod is enough to alter the compression ratio which means that in cold weather, the temperature of the diesel/air mixture cannot be raised sufficiently to combust - hence won't start.

Problem - its very expensive to fix - it cost me nearly £800.

Second thing - I was advised by the marine engineers NOT to continuously turn over the engine WITH THE SEA COCK open if it won't start. This can cause water to enter the combustion chamber anyway which then causes the same problem - but worse. Thay said if it hasn't started withing 5 to 10 seconds of turning over on the starter motor then start looking for the reaon why.

Hope this helps

Regards

Geoff Westgarth

 

[Guest]

Hal, The Bukh 20 was never great at starting in very cold conditions; I believe its to do with the cylinder head design but I can't remember the details. I don't think that 20/30 seconds cranking is that unusual to start the Bukh from cold but I would give the starter motor and your battery a rest by turning the engine over in shorter bursts. You should look at your starter battery, how old is it ? Batteries get tired and it may not have the strength to crank the engine fast enough to fire. If you have two batteries then use both for that first start, otherewise a cold start kit could be the answer......don't know the cost !

 

[Guest]

cold start kit around £140 easy to fit,about an hour.

 

[Guest]

If the engine is somewaht old, one thing to look at is the starter itself. My Volvo MD7A is 20 years old and the mechanic said it was cranking slowly. Took it off and had it serviced. The electrician who changed the solenoid and cleaned it up said it was "full of crud".... john

 

[Guest]

Hi Hal! One thought springs to mind. Run a tissue over the pipes from the diesel tank particularily at fittings and joints. If you find diesel on the tissue it may be that you have a minute air leak and over long periods the fuel in the pipe runs back towards the tank, or allows air in. Just a thought best of luck Rob

 

[Guest]

some suggestions in order of easiness 1/ does the engine have glow plugs? if it does, are they all working? are you waiting long enough for them to heat up?

2/ do you have an air leak that is causing fuel to drain away from the injector pump whilst the engine is stood? test - try bleeding your diesel system after the engine has not been used for a day or two. if it takes some pumping to get diesel through, you know you have a leak.

3/ is your starter motor spinning the engine reasonably quickly? check and clean the connections. is the battery sound - a high internal resistance could mean a large voltage drop when starter load is applied, and then a slow spin speed.

4/ is there plenty of compression on the engine. have you checked the tappets?

am probably teaching granny to suck eggs, but if you are anything like me, you start off with the complicated and unlikely causes, and work back to the simple and obvious!

 

[Guest]

When a load of hot air is a good thing !

I have a Volvo 2000 series single pot which is a dog to start in cold weather. The cold start is just an extra squirt of diesel - no glow plugs.

Made a monumental discovery over Easter !

It suddenly struck me that if I could raise the temperature of air going in it MUST help.

I closed the forecabin door, put the companionway slats in and temporarily taped up a vent. I put both gas hobs on and within about 5 minutes the place was like a sauna. Nipped out into the cockpit, put the companionway doors back and the engine started almost straight away.

Give it a go !

Regards, Vic

 

[Guest]

Try using oil which is thinner at low temeratures. For example Mobil 1 has a rating 0f 0w40 that means it is very thin when cold and there is less drag for the starter to overcome. The engine turns over faster and is easier to start. My MD1 has a hand starter and, not being built like Konan the Barbarian, I can use this effectively only with 0W40 grade oil.

If your engine is a bit tired then try a (ONE!) squirt of engine oil into the air inlet on very cold starts. This increases compression and will burn itself in the absence of other fuel. I do this for the first start each season and so far have started first pull. Do not put more than a squirt in or you may bugger the engine.

Martin D