Exhaust horn - an (expensive) cautionary tale

[Andy Bav]

Last Saturday eldest son reports that bilge pump kept going off for c10 seconds every 10 minutes, further investigation reveals a trickle of sea water coming into the boat from the rear of the port engine.

Emailed local VP dealer and also marina that we may need a lift on the Monday. Get an email Monday morning, needs a lift ASAP. Exhaust horn has corroded and when VP tried to tighten the connection the flow of water increased.

Once she is lifted it transpires that the exhaust horn has corroded beyond repair, and the Starboard is also “showing signs of corrosion”. Solution, to get access to the bolts, the engine needs to be lifted and moved forward.... as a precaution I have also had the starboard engine done also, as VP can’t guarantee how long it will last....

This years service includes bellows etc, but let’s just say that the bill for everything is absolutely eye watering, not helped by the fact that I am paying main dealer prices. Thankfully the floor of the dinghy garage is removable which made access easier, goodness knows how they would have done it without such access..

I checked with Volvopaul if anything could be done to prevent it, and despite a recall from 2012 onwards, not much could have been done, but the new ones to be fitted are a better design.

Boat 2010 V42 engines D6 370s.

 

[Switch]

Andy,

Sorry to hear that, that was something I always feared on my last boat fitted with D6 350's but i managed to dodge that bullet. Hopefully you can now enjoy the season. That may go some way in justifying the eye watering bills...boats eh? what can you do??

 

[Andy Bav]

Thanks. Indeed. Change of role at work means a later start to the season for me this year, so no time lost..

With the heat exchangers cleaned last year the engines are getting a bit like Triggers Broom !

 

[Seastoke]

Thanks. Indeed. Change of role at work means a later start to the season for me this year, so no time lost..

With the heat exchangers cleaned last year the engines are getting a bit like Triggers Broom !

Sorry for your,trouble could I ask a silly question are the D6 on legs as we have D6 on shafts

 

[Andy Bav]

Sorry for your,trouble could I ask a silly question are the D6 on legs as we have D6 on shafts

Legs.

 

[petem]

Legs.

Ouch Andy. At least you know they'll have done a good job, albeit not cheap.

 

[jimmy_the_builder]

I replaced the horns on my T40 when I did the refit three years ago. Very much not a bargain, as the OP says. The new design has an anode, to address the corrosion issue with the earlier version of the horn.

 

[volvopaul]

I still cannot believe how quickly the DPH exhaust pipe fails in that it rots away very quickly .
Only yesterday I changed the small rubber joint on a 1988 yes 1988 AD31 to find the aluminium exhaust pipe in perfect condition, the only conclusion I can make is that whoever casts the pipe for VP use aluminium of a very poor grade for it to rot away at the speed it does , it only corroded obviously where the metal meets air and salt water

 

[julians]

Lovely. I look forward to replacing these on my boat, its a d4 on a dph drive but I presume I potentially am in for the same problem?

I had a look on marine parts Europe and the part itself (if I identified it correctly) isn't too expensive, something like £350 for the short version or £1200 ish for the long. I presume its the labour that's costly. Does the engine have to be moved for all installations or is it only certain boats that need the engine moving.?

 

[volvopaul]

Lovely. I look forward to replacing these on my boat, its a d4 on a dph drive but I presume I potentially am in for the same problem?

I had a look on marine parts Europe and the part itself (if I identified it correctly) isn't too expensive, something like £350 for the short version or £1200 ish for the long. I presume its the labour that's costly. Does the engine have to be moved for all installations or is it only certain boats that need the engine moving.?

The engine doesn’t have to be extracted if there is sufficient room to move the engine forward about 6 inches , if there is no room the engine has to be lifted out at an angle either enough to get at the bolts where the pipe joins the shield .
In some cases the coolers are usually ready to be overhauled so it’s an easier fix with the engine in the workshop.

If you can see stains of salt water running from the rubber joint down the pipe the chances are it’s getting corroded .
There is a plastic insert that can be fitted to give it a few more years life which slides over the pipe , you get a tube of special sealant to make it good.
In some cases the pipe is that bad it’s not possible .

 

[julians]

Thanks Paul that useful info. I was having a look at that area last weekend and it all appears OK, so hopefully I won't have the issue for a while yet.

Although the boat is from 2006 and I have had every single other common d series issue so far..

 

[oldgit]

same old same old...........
Exhaust horns on my 40A with 280 outdrives corroded away at the top and needed a little repair kit.
Saved me lot of time and trouble but merely postponed all the aggro and expence for the next owner.
The bolts securing the horn to the transom casting were actually recessed into the transom and would have been virtually impossible to get at, suspect the four securing bolts would have simply sheared at any attempt to undo.
Would have thought VP should have solved the problem after 39 years. ?