White smoke and hollow exhaust sound D2-55

[PEA-JAY]

Foul smelling white smoke and a hollow sounding exhaust made me decide to carry out a compression test on the D2-55 and cylinder number 1 had no pressure at all. Removing the cylinder head I found a corroded exhaust valve and seat. The smoke condition happened quite suddenly so I’m concerned it could happen again unless I find the cause! The other cylinders and valves are intact.
Someone suggested the raw water syphon breaker failed but it’s fine.

Has anyone experienced the same problem and discovered the cause? My engine has less than 1500 hours in 14 seasons.

I will appreciate any help in this matter.

Raph.

[dawntreader]

One consideration I have is that corrosion on the seat and valve may be due to water ingress whilst the engine has not been in use - has it been static for some time? Damp air can get back into the engine through the exhaust and the reason only one valve is affected could have been due to it being 'open' whereas the others would have been 'closed' depending on what part of the cycle the engine was on when it stopped. Are there any traces of white oil in the valve case or filler cap - even very minor traces?
I note that you are in Malta but I am not sure how 'wet' it gets there 

[PEA-JAY]

There was a longish period, perhaps 4-6 weeks, when the engine was not started. There is no oil contamination and everything else seems normal.
Malta has quite a high humidity level practically all the year round, however inside the boat is kept quite dry during the wet months with a dehumidifier automatically set at 55%.

[dawntreader]

With no sign of water ingress and 4 - 6 weeks is not a long period to worry about not running the engine the corrosion is puzzling. Do you have any photo's of the corrosion?

[JEN-et-ROSS]

Removing the cylinder head I found a corroded exhaust valve and seat.

Could the valve and seat be burnt rather than corroded?
Not nearly so common these days with more durable alloys but the older blokes will remember regrinding valves and seats using those funny little double ended tins of grinding paste and a wooden dowel with a sucker on each end. (I've still got both)
A flaw in the valve materiel or casting could allow the combustion flame to erode the valve and seat quite quickly and it might look like corrosion.....

[Yngmar]

Could it have come from the exhaust?

Assuming you didn't have problems starting the engine and cranked for a long time with the intake seacock open, so flooding from that can be ruled out.

But theoretically a strong gust funneling up the exhaust outlet in just the right way could blow a bit of spray from the water muffler up the exhaust manifold into whichever cylinder had its exhaust valve open. Malta did get a lot of strong winds in the recent "Medicane", which fits the timeframe.

Just a theory 

[PEA-JAY]

Unfortunately I don't have photos of the parts. There were no starting problems. No contamination of the lube oil. I also very much doubt the wind could have pushed any water back all the way up into the exhaust manifold and into the combustion chamber. I found pitting on the piston crown as well as corrosion on the rim of the exhaust valve and the valve seat insert. Number one cylinder doesn't seem to have been working at all from all the carbon deposit on the piston and I think un-combusted fuel must have been the reason for the smoke.   

Unfortunately, I'm told, this could be a serious problem with the cylinder head itself! I've sent it to a specialist company and I'm waiting for their report. 

In the mean time I have researched the engine and it's a Perkins 404D-22 manufactured by Siabaura in China (or Japan). Complete heads+valves are available from different sources.

The Siabaura engine is widely used by tractor manufacturers so most parts are readily available on the market (and internet) at a fraction of the VP price.

Raph 

[Salty]

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In the mean time I have researched the engine and it's a Perkins 404D-22 manufactured by Siabaura in China (or Japan). Complete heads+valves are available from different sources.

The Siabaura engine is widely used by tractor manufacturers so most parts are readily available on the market (and internet) at a fraction of the VP price.

Raph

Shibaura is a Japanese engine manufacturer.

[Symphony]

The engines are made by a joint venture with Perkins and are assembled in both Japan and Peterborough. Mainly used in small tractors and marinised as Volvos.

[MarkTheBike]

...and marinised as Volvos...

and bump the price by 400%!

[Symphony]

...and marinised as Volvos...

and bump the price by 400%!

Volvo prices are virtually the same overall as all the other major marine engines. Remember the marine components are made in the hundreds each year rather than the hundreds of thousands base engines.

[JEN-et-ROSS]

Volvo prices are virtually the same overall as all the other major marine engines. Remember the marine components are made in the hundreds each year rather than the hundreds of thousands base engines.
[/quote]

No I don't think they are. Volvo spares are far more expensive than others.
 We used to have a Volvo 2003 and when I asked why the high prices, I was told with a straight face that it was to " ensure a World wide distribution network. "

[Symphony]

Volvo prices are virtually the same overall as all the other major marine engines. Remember the marine components are made in the hundreds each year rather than the hundreds of thousands base engines.

No I don't think they are. Volvo spares are far more expensive than others.
 We used to have a Volvo 2003 and when I asked why the high prices, I was told with a straight face that it was to " ensure a World wide distribution network. "
[/quote]

Suggest you look at the cost of Yanmar spares before you make that comment. The 2003 is now nearly 30 years out of production, was only built in tiny numbers and was unique to the marine market - as well as being made in one of the most expensive countries in the world.

[PEA-JAY]

 I'm still unable to find the cause of ( probably) salt water ending up in cyl.1 and trying to explore all avenues. Can anyone tell me if the water lock is just an empty cylinder or contains some servicible component. Mine is a VP unit.

[Yngmar]

Can anyone tell me if the water lock is just an empty cylinder or contains some servicible component. Mine is a VP unit.

Nothing serviceable inside: https://www.marinepartseurope.com/en/volvo-penta-explodedview-7746710-25-360.aspx

They are however prone to corroding through at the bottom end where the water sits. If it leaks, it will be typically leaking at the lowest point.

[PEA-JAY]

Thank you Yngmar. No point in stripping it down then.
I'm still waiting for the cyl head report but find it hard to accept my coolant is leaking into the cylinder as if this is the case I would be topping it up all the time

[SYJetzt]

Hi to all, i´m new here!
I dont have expierience on D2-55, but with elder Mercedes OM616 engines, which are quite the same stuff.
 
You said your problem is on the first cylinder (the opposite side to the saildrive!). If this is correct, it seems unlikely to be raw water from the exhaust System (the water has to pass all other cylinders to proceed to the first one!). More likely seems to be a leak in the head or the head gasket. If you have a leak in the closed inner water circuit, there is not neccessary a noticeable loss of cooling fluid. In such cases sometimes the inner coolant circuit gets under pressure from the combustion gas and causes change of colour of the cooling fluid. You should check this
Excuse my bad english, but i hope it helps.
Robert

[Ronald]

Did you check the exhaust elbow, it appears to corrode sometimes and could be a cause for backwashes to the cylinders. The corrosion can not be seen from the outside.
I say could as I have no experience with this myself, but have read about water getting in to cylinder because of that.

Ronald.

[PEA-JAY]

Hi. To pick up where I left off ...
The cylinder head was tested and no cracks found. No sign of a blown cylinder head gasket. No loss of coolant. No noticeable change in coolant color. Mixing elbow replaced some years back with a custom made stainless steel one that discharges water a good 3” lower than the OE part.
I don’t have the habit of revving up the engine before switching it off.
Anti-syphon valve working properly at time of inspection unless it has been playing up un-noticed.

Starting from the last item I’m changing to a continuous flow option using 4mm i/d tube discharging into the waterlock.
I’m thinking of adding Wonderweld or similar product with the coolant as a precaution  although I’m getting some negative comments about clogging (?)
I am rebuilding the corroded heat exchanger flange to avoid any water pockets close to the exhaust manifold.
I cannot think of any other precaution I can take and  I welcome any new suggestions.
Thanks.