rain water accumulating under engine

[aquapore]

I have recently bought a Bav 41 2003 model and have noticed fresh water accumulating under engine. I have searched for leaks in all the obvious places, but found none.

Any suggestions where this water might be coming from.



Thanks

[1055john]

Not sure if it is the same on your boat, but if there is a box for the emergency tiller between the two helm wheels, see if there is a drain plug which is blocked. Water drains into this box when it rains or you wash down the boat/cockpit. If the plugs blocked water then builds up, runs down the rudder stock and ends up under the engine. I got really worried by this problem see April post, but is was a real quick fix. Hope yours is as simple.

[aquapore]

Thanks for the suggestion - my boat only has one helm. I will check this out with a liberal dose of fresh water.

Regards

[Anthony]

I too had fresh water accumulating under the engine which I traced to a small but regular drip from the water heater outlet. To test for this I suggest you completely dry under the engine, leave a sheet of paper towel there and when leaving the boat, ensure that you have turned off the water pressure switches. See whethjer that patch is dry on your return. I fixed that problem with a new length of pressure hose from the heater, and gave the mass of hose connections near the heater some support straps.

[JEN-et-ROSS]

I have an older B38 and had the same problem and after searching for and resealing every possible potential source of rainwater I discovered that the pressure relief valve on the calorifier ( it has a short length of pipe attached that leads under the engine ) was the problem. It had eventually dawned on me that the water was only appearing after running the engine long enough to heat the water. If the system was already pressurized i.e. pump on I guess extra expansion of the heated water is overcoming the weak valve.

[Salty]

I'm not familiar with the arrangement of a B41, but some years ago I had fresh water leaking into my B36. On investigation it was found to come from the holes for the screws that secured a thick plastic cover in place in way of the area just behind and below the bridge seat at the after end of the cockpit. The plastic cover was secured by four self tapping screws through the cover and through the glass fibre hull moulding below. The cover when in place fitted flush with the cockpit deck, and was supported each side by a GRP ledge that was below the cover by an amount equal to the thickness of the cover. Over time, the holes for the self tapping screws had worn to the point that the screws were only a sloppy fit and did not actually tighten when done up. Whenever the cockpit area was washed down, or when it rained, water would run out of the cockpit at the aft end, passing under the cover and along the ledges supporting the cover. Arriving at the screw holes water would run through into the area around the steering quadrant, then it would run forward to the engine compartment.
The problem was solved by drilling out the holes to get back to sound undamaged GRP and the cover was then bolted in place with a large penny washer fitted to the bolt where each arrived inside the steering compartment, and a nut. Between the cover and the ledge an "O" ring or something similar was fitted around each bolt and when the bolts were tightened the "O" rings were squeezed up to form a seal. While using bolts does present problems when tightening them, particularly if you are on your own when doing the job. Since then there have been no further leaks from that area. Good luck.

[IslandAlchemy]

Get into the sugar scoop and see if there's any sign of wet in there. It may well be coming from deck fittings of the cockpit drains and then running forwards into the engine sump.

[aquapore]

Thanks for all the suggestions.  I noted that the there was at trace of water penetrating the holes where self tapping screws have been used. Any suggestions for sealing. I would rather use through bolts with rubber or fiber washer but that is going to take a lot of time and may not be possible for all situations


Regards

Aquapore

[Salty]

Further to my previous comment, after drilling out the holes to get back to firm laminate, I filled the holes in the hull moulding completely with GRP filler and resin, but I was not happy that this was the best way to do the job, and I was not entirely convinced that the filler had fully bonded with the GRP laminate of the hull. I also considered using aluminium rivet nuts, but in that location the thickness of the hull laminate was more than the rivet nuts could cope with and hence the decision to use long bolts. Provided the bolts used are long enough for you to hold the inner ends of the bolt as you tighten the nuts, then you can do the job on your own. An alternative might be to have a length of light stainless rod welded to the nuts such that the nuts will automatically jam against the internal structure within that area, allowing you to tighten the bolts externally once the nuts are in place, but this will need a second person to assist to start the bolts rotating into the nuts. If you could get some really thick self tapping screws that would take up the slack caused by wear in the original holes, that would be the easiest way to secure that plastic panel in place. As a last resort I suppose you could fill the holes in the hull moulding and drill new ones through the plastic panel and make new holes in the hull moulding for whatever size of self tapping screw you want to use.
Good luck with whatever you choose to do.