Engine room ventilation / oil leaks

I have a Volvo Penta 2020 on my Hanse. It has been leaking a little oil through several gaskets. The service guy says it could be due to high running temprature and deficient cooling system. We have used the engine up tp 3000 rpm, sometimes even 3200 rpm. The service guy suggests we make a ventilation pipe and a fan to the engine room. I wonder if this will help.  The engine is supposed to be cooled by sea water. Do you have any better explanations for the leaks or better repairs for the cooling system. I have never seen any warning lights for the cooling system, nor are there any smells. The engine is ofcourse warm after use, but I am not convinced it is too warm.

There are two leaks, one in the rear end where the gear is joined with the engine and one in the front end so that the leak is visible as soon as I open the engine room box. They are both really small, like two drops a week. But it would be nice to have an explanation. The Gaskets will be changed this year because of the s-drive gasket renewal.

Have just spotted the title of this thread which has prompted a different thought in my mind.  I am running a Yanmar 2GM20FC on our 341 - given that the engine air intake is within the engine bay, how can I be sure that there is adequate ventilation to the engine bay to ensure full engine efficiency?  I am not aware that the engine bay is vented for this purpose, indeed it is very well insulated for noise etc; or is there some ducting which I have failed to spot?

Volvo or Yanmar must be able to supply the volume of air displaced at max RPM, if not multiply 3200 rpm by engine size and divide by 2 for a rough estimate. The engine room air intake must be that, plus cooling air flow possibly 30% more.

 

The cooling air is not as important as the water cooling flow, but still necessary and isolated hot spots could occur particularly at the back of the engine.

 

If the raw water output is not pumping around a bucket of water per minuet then it is possible the impeller has a broken blade.

 

This could result in localized over heating and quite possibly oil leaks but more likely blow-by gas is pressurizing the oil at the engine speed you mentioned.

 

Andrew 

The same question for the 2008 hanse 320....there's only one duct with a blower which is not working from new...praise the yard!!! but anyways...
From my experience working for 5 years as a boat mechanic I haven't seen too many smaller boats with 2 ducts...to be honest this is unnecessary for such small engines - their air consumption is really low...so no worries...the engine will breathe the way it should even if there's no ducts at all...it will simply consume air from the saloon...it will steal your air....so open up at least one hatch or you will eventually suffer from hypoxia....
The blowers are obligatory in gasoline engine compartments and where the engines are big with huge air consumption...

As for the oil leakage - it definitely has nothing to do with the ventilation problem...


Edited by Windsurfer - 07 June 2010 at 08:22