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Hi all,
Just wanted to share with you a lesson I have learned this week….
We were away with CaSam motoring (where was the forecast 4/5?) East just off of Hayling Island when I heard the sound of water down below.
Upon inspection, I found that the engine bay bilge was full of seawater. Quick checks revealed that we were not holed and that the seacock was intact, we were taking on water but not rapidly.
We made an emergency course change and pulled into Sparkes Marina.
After about three hours of bailing and mopping (around 10 buckets full!) I found the root cause of the problem – the exhaust muffler / water lock had perforated and so part of the raw cooling water was being pumped straight into the boat.
A couple of phone calls later and Richard at Clipper (Thanks Richard!!) had organised engineers to come to the boat the following day with new parts to get us sorted and back on our way. (I also need to add that Phil the resident engineer at Sparkes is also a stand up guy who went out of his way to conjure up an emergency “get you home” plan in case the situation could not be quickly resolved!)
Some learning’s from the day;
• Do not assume that relatively new things will not fail (15 months old part with 104 engine hours)
• The engine bay is partially sealed off from the main bilges. Before anything gets out from it, it fills; the engine bay, under the fuel tank and the rear berth, the battery compartment, the portside locker bilge, behind and under the heads, then the stringers BEFORE getting to the bile and the pumps!
• Water in confined spaces is blinking difficult to get out
• Read the small print of your warranty
I would hate to think what might have happened if we were on a longer cruise or even overnight if the kids had been asleep in the rear berths….. not only was it water leaking out but also exhaust fumes!!
Attached is a photograph of the offending item after I had removed it – note the perforations and also the rust staining on what is supposed to be stainless steel?
Hopefully you will never have this part fail – for me, it is now something that I have added to my “Must check” list!!Safe Sailing
Steve[attachment=0:u1vqew21]Failed Exhaust (640×478).jpg[/attachment:u1vqew21]CaSam et al…..
This isn’t a new problem. I had exactly the same failure about four years ago on my B32 ‘Another Fantasy’, which I reported on the website at the time. (Unfortunately the old posts seem to have disappeared from the ‘new’ site). When the muffler first began leaking (just a slight weep, in fact), I had the seams re-welded by an engineer in Chichester Marina. This was quite effective to begin with but after a while the same problem surfaced again, so winter-before-last the engineer fabricated a new muffler end cap from thicker and supposedly better quality steel. This seems to have cured the problem thus far; no sign of any breakdown and the welds are holding up and was cheaper than buying a complete new silencer!!
The muffler isn’t the only point of failure in the exhaust system. I’ve also had to replace the exhaust elbow (the heavy casting which connects the exhaust pipe to the manifold and which incorporates the cooling water exit from the heat exchanger.) The casting had corroded from inside, to the extent that cooling water and more worryingly exhaust gas was able to escape through a small hole which appeared at the bottom of the casting. At least there was prior warning of this failure: rusty water dribble marks on the side of the cylinder block, adjacent to and below the elbow. I’ve taken the precaution of fitting a carbon monoxide detector in the aft cabin, should the same thing happen again.
Unfortunately we’re at the mercy of the laws of physics and chemistry: some metals and sea water just don’t mix very well…..since these problems occurred I always check the engine for any sign of leaks. It helps if you try to keep everything scrupulously clean.
Ian Culley
B32 Another Fantasy
What type of exhaust muffler have you had fitted as a relacement?
@moodymike wrote:
What type of exhaust muffler have you had fitted as a relacement?
It’s another Volvo Penta part…. same as the original (as covered by the warranty).
Strange thing is, Phil at Sparkes had an old unit that looked like it was around 10 years old and the metal work stil looked to be in great condition….. is this a sign of modern day Volvo value engineering?
I have heard of plastic “Vetus”? units but have also been told stories of them melting… anyone know any better?
Steve
@another fantasy wrote:
Ian Culley
B32 Another Fantasy
Fair shout Ian and a good watch out for us all.
No, the Vetus plastic ones don’t melt. Used them for more than 20 years without problems. The installation in a Bavaria has the muffler/trap well away from the exhaust, and Vetus recommend a minimum of 300mm – guess on my 37 it would be at least 3 times that. However, not sure the pot type would fit in the space. An alternative is the GRP units from Halyard Marine. They make tubular ones similar shape to the Volvo unit. Not yet measured up whether they have one to fit as my original one is still sound after 12 years (famous last words!) – but I do inspect it regularly.
Have been looking at the Halyard tubular unit,looks as if it could be an easy replacement. I am confused about the term Waterlock and Muffler, what actually is contained within the original Volvo box? Does the Halyard work in the same way?
@moodymike wrote:
Have been looking at the Halyard tubular unit,looks as if it could be an easy replacement. I am confused about the term Waterlock and Muffler, what actually is contained within the original Volvo box? Does the Halyard work in the same way?
As I am lead to understand it;
By not just having a straight through exhaust,the “muffler” aspect is created by breaking up the sound waves and feeding the noise / gas through a pool of water that gathers in the system (similar to a car although that uses baffles in the box).The “water lock” feature stops the back flow of water as the engine decompresses as it is turned off.
I am not sure about the Halyard one but I am guessing that as it is such a simple solution the theory behind it would be similar.
Hi All,
The exhaust muffler shown in the photo appears to be made from stainless steel, and therein lays the problem, particularly if your boat remains idle for longish periods of time. While stainless steel is a lovely material that does an excellent job in most situations, it is not foolproof. It’s Achilles heel is when it contains salt water that lays stagnant for a longish period of time. When that happens the stainless steel will corrode and let you down. Much better in my opinion to use a plastic muffler, just don’t let it get too hot !
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