TAM61's

[tamarind]

TAM61\'s

I am looking at a boat with twin TAMD61 A's. The engines have been very well looked after and very clean. When under way I noticed a bit of steam coming out of the crankcase breathers, it is definately steam not smoke. Every thing else is as it should be, all gauges are reading normal, no over heat. Is this to be concerned about? what could be causing this? Any ideas would be appreciated.

 

[stuartw]

Re: TAM61\'s

You don't say how many hours the engine has done, but the TAMD61A is very strong (as discussed a few weeks ago on this forum). If all operating conditions are seemingly normal, then I suspect there is not much wrong.

However, your "steam" puzzles me. Are you absolutely sure that this vapour is coming from the crankcase breather.? Just above that, is the charge air cooling, heat exchanger. The 'O' rings can leak and drip sea water, causing salt build -up, steam and corrosion of the breather filter box. Sometimes this situation only manifests itself at full wack. So unless you are down in the engineroom during those conditions, you'll never actually see it. You will see the after-effects at tickover though.
Also it is worth checking that you get full revs under load. This should be between 2800-2900 rpm. Also check the history of oil consumption. This should be around 0.1 to 0.5 % of the fuel consumed.
That's about all I can think of for the moment.

Stuart

 

[TonyJones]

Re: TAM61\'s

If it is coming from the breather and the boat has been out of comission for a time, it could be condensation emerging from the crankcase. OTOH, it could indicate water in the oil, so caution (and an engine survey?) is called for.

 

[tamarind]

Re: TAM61\'s

Thanks for replies. The steam is definately coming from breathers at tick over and at full wack. No other drips any where. she pulls 2800 flat out and aparently burns half a litre of oil every 100 hours. The boat has done 2100hrs. The engines are immaculate with full service

 

[stuartw]

Re: TAM61\'s

I hate to be sceptical, but frankly, I would not believe that oil consumption. The sump of those engines contains 20 litres of oil. Half a litre loss would not even show on the dipstick. I would expect at least half a gallon/100hrs , particularly as it has done some 2100 hrs.
As regards your steam, I initially thought about crankase condensation, but dismissed it, as within a half hour of running at full working temp, it should dissappear.

Another possibility is water lying in the bottom of the sump pan, which would take some time to boil off. If there is sufficient quantity of water in the oil, then it would become emulsified, and would be a milky colour, although I am sure that aspect has been checked.

Again, not knowing what tests were carried out, the only other possibility, is that this steam could be unburnt diesel fuel mist, being forced past a piston, in a none working cylinder. This would of course pressurise the crankase and naturally be vented.

Generically, they are good engines, and even 2100 hrs is not high. However, as they represent a fair chunk of your investment, I think you should at least get to the bottom of this "steam". If for nothing more than your peace of mind.

Stuart

 

[capsco]

Re: TAM61\'s

You say it is definately steam not smoke, how easy is it to tell the difference between steam and "oil mist" with the oil element removed,
, this is exactly what the breather filters are supposed to do, if you shine a torch into a dark hot engine room [Volvo] in the direction of these filters I would be suprised if you did not see this symptom in all cases.