Engine starting in Winter with Summer fuel

[Appledore]

Happy Easter Gentlefolk!,

The boat's finally back on her mooring after a winter of very little maintenance due to the foul weather. Both times I tried to start the engine - Yanmar 1 GM 10 - it turned over really well, but took ages to eventually fire and run, coughing and grunting, but when it did run it was fine.

I thought I may have had air in the system as I had replaced the fuel filter before Christmas, but fuel was running OK when I bled the various points. I did think it would start OK on the second day, the day of craning-in, but it was actually worse. The weather was fine, but below freezing at 6 am!!

My son then reminded me that I was still using a full tank of summer diesel, which was purchased in July, and last used in the boat late September. Of course, Winter diesel for road vehicles has additives to prevent thickening, or whatever it may be that causes poor winter starting. From your own experiences do you think this may be the cause of poor starting? Obviously when the temperature rises I would hope the starting becomes virtually instant, as normal.

Geoff

 

[Tranona]

The 1GM does not have glow plugs so is often difficult to start in very cold weather. Turning over a few times with the decompressor up sometimes helps as does warming the incoming air. However the latter is usually impractical on most boats. Having the engine control wide open can also help. Once the ambient temperature gets up the problem will almost certainly go away.

 

[earlybird]

I agree with the above. My experience of Yanmar GM's is that they are poor starters in cold weather.
I don't think "summer fuel" has any bearing on the issue.
If you are turning the engine over on the starter for extremely long periods, give the starter-motor time to cool down between attempts, and consider closing the cooling water seacock to prevent flooding of the exhaust, but that need would be fairly extreme.

 

[VicS]

Happy Easter Gentlefolk!,

The boat's finally back on her mooring after a winter of very little maintenance due to the foul weather. Both times I tried to start the engine - Yanmar 1 GM 10 - it turned over really well, but took ages to eventually fire and run, coughing and grunting, but when it did run it was fine.

I thought I may have had air in the system as I had replaced the fuel filter before Christmas, but fuel was running OK when I bled the various points. I did think it would start OK on the second day, the day of craning-in, but it was actually worse. The weather was fine, but below freezing at 6 am!!

My son then reminded me that I was still using a full tank of summer diesel, which was purchased in July, and last used in the boat late September. Of course, Winter diesel for road vehicles has additives to prevent thickening, or whatever it may be that causes poor winter starting. From your own experiences do you think this may be the cause of poor starting? Obviously when the temperature rises I would hope the starting becomes virtually instant, as normal.

Geoff

There is a difference in spec between summer and winter grade diesel.. the "cloud point" and more importantly perhaps the "cold filter plugging point" are lower for winter grade.

You should be able to find the specs on line but I doubt if it has been cold enough to be a problem, but it may have been. I forget the figures without looking them up.
The trouble is if wax does form in the fuel it is quite difficult to get it to redissolve. It can be avoided by adding some paraffin to the fuel remaining at the end of the summer ( IIRC up to 10% is acceptable....technically but of course there is all the b*llocks about tax )

 

[charles_reed]

Waxing of diesels really only occurs where the local temperature is >-15C, though this could happen at the tip of an injector, that's a passing problem the waxing in pipes from tank to engine are the real problem.
In the absence of anything else it is possible to add petrol (legal) or paraffin (illegal) at the rate of up to 8%, though I don't think it's particularly good for a diesel engine.
The refusal to flow can have two causes - the polymerisation of certain of the diesel hydrocarbons, or ice crystals suspended in the fuel.
Once the waxing has taken place additives will probably not work as they can't get to the site of the problem, they need to be put in a long time before.
Personally I doubt that waxing was the problem with your engine - rather thick lubricating oil and a feeble battery. The old GM range, though indirect injection, had no glow plugs, so relied in cold weather to an excess of diesel in the bore, raising the compression ratio until the engine fired. Worn rings or bore could make that a long time.

 

[TonyBuckley]

Doncha love 1GM10s!!!!!

I have started mine recently a few times when below freezing (just) and my tank is also filled with forecourt diesel from Summer.

Apparently full throttle opens up some advance thing and is the correct way to start.

Mine started on second attempt each time with the first crank running for something like 5 secs.

 

[Appledore]

Thanks for all your helpful comments.

I have two good batteries and use them both when engine starting. There's no lack of power there. Engine in full throttle, with a few turns with decompressor open, but it still has difficulty in 'picking up'. As I said, once started there is no problem.

I'll just put it down to the cold temperature, and see what happens in a couple of weeks time, when the temperature rises to normal. Yeah, OK!

 

[charles_reed]

Thanks for all your helpful comments.

I have two good batteries and use them both when engine starting. There's no lack of power there. Engine in full throttle, with a few turns with decompressor open, but it still has difficulty in 'picking up'. As I said, once started there is no problem.

I'll just put it down to the cold temperature, and see what happens in a couple of weeks time, when the temperature rises to normal. Yeah, OK!

Imagine - you've got one pot, with about 15cc of raw diesel swilling about - when you do fire, getting rid of that lot is going to take some time - in fact it's going to take about 20' running at 1200-1300 rpm before you can clear your lung.
Having been involved with early diesels, which had a habit of failing glow plugs, I can assure you that, given enough battery and time they can always be started, but the resulting clouds of smoke and noises in the motor are terrifying to beholders and thoroughly anti-social.
The latest Yanmars, the YM, have glow-plugs, though even @ -8C I've not had to use them. Modern direct-injection common-rail engines just inject additional diesel in and usually start of 4-5th revolution.
Worst of all were the Gariner 6L in cold weather, but when you did get them running they were sweet as a bell. Mind you 350 rpm tickover and 1800rpm top limit compared to modern indirect diesels with 800 and 3600 and common rail ones with 900 and 6200.
All the Yanmars are obsolescent technology, which accounts for their longevity, reliability and low cost (unless AEB are in the supply chain)

 

[Athene V30]

I forgot to move the throttle and the 1GM10 started within a few seconds of turning the key on the pre launch run up.

The fuel is a mixture of red and white bought over the previous 12 months.

After launch took boat happily about half a mile to berth.

I am not mechanically minded!

 

[Rossynant]

"Summer diesel" should not get thick even in some -5 C, but I have no idea what they sell in UK. Thickening applies to just heavier fractions in fuel, those may block the filter no matter how little of them there are. If this is a source of problem - warm up the filter, so it flows out. Sometimes also blockage can form in fuel pipes.
Second source of problem - water in fuel. This naturally will freeze somewhere and can block piping or filter.

Another thing is starting the engine while it is so cold. Any problem, like worn injector or lower compression may not show normally in UK, but below zero... Normally diesel engines have some devices for cold start, but engines on boats happen sometime to have none... not that I could understand why.

Anyway warming everything to just couple deg above zero will solve he issue.

Happy Easter! - greetings from Poland, where we have Easter Bunny shaped Snowman in the garden...

 

[NormanS]

Imagine - you've got one pot, with about 15cc of raw diesel swilling about - when you do fire, getting rid of that lot is going to take some time - in fact it's going to take about 20' running at 1200-1300 rpm before you can clear your lung.
Having been involved with early diesels, which had a habit of failing glow plugs, I can assure you that, given enough battery and time they can always be started, but the resulting clouds of smoke and noises in the motor are terrifying to beholders and thoroughly anti-social.
The latest Yanmars, the YM, have glow-plugs, though even @ -8C I've not had to use them. Modern direct-injection common-rail engines just inject additional diesel in and usually start of 4-5th revolution.
Worst of all were the Gariner 6L in cold weather, but when you did get them running they were sweet as a bell. Mind you 350 rpm tickover and 1800rpm top limit compared to modern indirect diesels with 800 and 3600 and common rail ones with 900 and 6200.
All the Yanmars are obsolescent technology, which accounts for their longevity, reliability and low cost (unless AEB are in the supply chain)

I presume you mean a Gardner. I had a 6L3, and it never gave any problems starting, summer or winter. When used in marine applications, max rpm is / was 900, although I normally cruised at 750 rpm. Beautiful engines, and built to run and run.

 

[patturner]

I went on the boat today and tried starting the 1GM10 after not being used since early February. She coughed and died after 5 seconds on first turn of the key.
Second turn she started, cough a couple of times then ran smoothly after about 30 seconds. I was well chuffed as the boat has been on the water all winter and because of the weather has had very little attention. I thought I would get some winter sailing in but have sailed just twice this winter. The sooner this weather changes the better!!