D2-55 New Exhaust Elbow?

[MagicalArmchair]

I have taken the elbow off the engine to inspect it and the intake is about 50% rusted up. The exhaust airway itself is pretty clear. Do I chip out that rusted intake, repaint, and reattach?

Or do I replace with one of these suckers? https://www.parts4engines.com/volvo-penta-d2-55a-and-d2-55b-stainless-steel-exhaust-outlet-and-connector/

[Lazy Pelican]

You know the answer- for peace of mind spend the money!

[AFRiCA]

Two years ago i removed and checked the same exhaust elbow as part of my preventative maintenance program on my 2001 Bavaria 42 with the VP 50hp engine (Perkins Prima 50) due to numerous reports re the clogging of the elbow and found it to be significantly clogged up with carbon deposits. There was really no option other than to replace the part. I ordered the part from Parts4Engines and had it delivered to Australia within 10 working days. My opinion is, spend the money, replace the elbow and the connector for trouble free motoring. Note:- I purchased the elbow and connector for a Perkins Prima 50 and fitted exactly. The price for the Perkins Prima 50 parts were significantly cheaper. Also available from Parts4Engines.

[markleuty]

I too spent the money and bought the stainless steel one.

Only had it a year and have yet to inspect the innards to see how it was getting on, but the old one was horrible inside and it had caused us numerous problems, so figured it was worth getting something a bit better.

Mark

[Yngmar]

Give the two hose ends a few taps with a hammer and see if the metal is still good. On our MD-22 the exhaust injector (the small bolted on part) does crumble to bits after 2-3 years and needs replacing. Never had to replace the actual exhaust elbow itself yet, just cleaned up and re-painted. I switched to the stainless injector this time, will see how long that lasts.

Different engine though, it looks like on yours the deposits go further down the exhaust which may effect where the metal rots.

[JEN-et-ROSS]

Our original Volvo Exhaust Elbow looked like yours, so I 'tested' it along the lines suggested by Yngmar. The end that fits into the exhaust hose shattered rather easily as the metal was mostly rust..
So, if in any doubt just buy a new one for the peace of mind.....Bill

[MagicalArmchair]

Thank you all, I've bitten the bullet and purchased a SS one (Christmas cancelled then ). Any tips for fitting it? I'm guessing the Hylomar it comes with is to smear the gaskets with pre fitting?

Anything worth looking at whilst its off?

Does the below sound about right?:

• Clean up mating surface on the engine.
• Put the gasket on engine smeared with the Hylomar.
• Fit Elbow to Engine. Do up nuts in diagonal pattern. Copper slip on these? (I've had aggro with this on my old boat http://www.albinballad.co.uk/how-tos/remove-a-sheared-off-exhaust-elbow-bolt/)
• Fit gasket (with Hylomar) and intake to the elbow, Copper slip on those bolts too?
• Refit the intake hose and the Exhaust hose. Test.

[Keweetoo]

Whilst the exhaust elbow is off suggest you carefully check the mating surface of the heat exchanger and make sure the metal is sound. On mine the severe restriction of the elbow caused back pressure and water erosion on the heat exchanger such that it perforated allowing water into the engine (rebuild necessary). See photo attached of perforation. I don't know the time it took to erode the heat exchanger (probably many years) as boat was new to me, but keeping the exhaust elbow clear of severe obstruction is key.

[JEN-et-ROSS]

Whilst the exhaust elbow is off suggest you carefully check the mating surface of the heat exchanger and make sure the metal is sound. On mine the severe restriction of the elbow caused back pressure and water erosion on the heat exchanger such that it perforated allowing water into the engine (rebuild necessary). See photo attached of perforation. I don't know the time it took to erode the heat exchanger (probably many years) as boat was new to me, but keeping the exhaust elbow clear of severe obstruction is key.

Ouch..!!  Goes to show that an external inspection is not enough. We should all take note...

[MagicalArmchair]

Whilst the exhaust elbow is off suggest you carefully check the mating surface of the heat exchanger and make sure the metal is sound. On mine the severe restriction of the elbow caused back pressure and water erosion on the heat exchanger such that it perforated allowing water into the engine (rebuild necessary). See photo attached of perforation. I don't know the time it took to erode the heat exchanger (probably many years) as boat was new to me, but keeping the exhaust elbow clear of severe obstruction is key.

Ee gads, was it the airways that were restricted? As opposed to mine where it was the intake that was getting blocked? I took a VERY bad photo into the engine once I had the elbow off, I'll take a better one when I get down next. The bit in red looks like the exhaust has been weeping a little from the bottom of the elbow, which means exhaust gases would have been seeping out too. One of the reasons I bumped the job up the list was because that cabin smelled a bit too 'enginey'. I did wave my Carbon Monoxide alarm around the area with the engine running, and it didn't go off, so it may well be a red herring. Still, I'm glad I made the effort. Thanks for alerting me to that.

Remaining questions:

• Copper grease on the nuts?
• Smear Hylomar on the gaskets pre fitting?

[Yngmar]

Yes to copper grease on the bolts. Also, have a peek in the hose ends - that's a mating surface too and if not smooth (e.g. wire reinforcement broken through), it will leak and corrode the new elbow needlessly.

[Florian68]

Just for curiosity reasons: How many hours did the engine run until the elbow looks this way?

[MagicalArmchair]

Thanks Yngmar. I'll check the hoses and put some silicone grease on those as well to try and help that seal.

As for the hours - that's yet another job I need to do! The LCD display on the taco is (predictably) cooked, so I need to replace that (watch out for a thread on that soon, eep). Once I know Florian68 I will report back.

The new exhaust elbow is due to arrive today, so hopefully I'll be able to put that all back together at the weekend.

[Florian68]

I changed the LCD display on my boat in October, I found this video quite good and it is really just a 15 Minute job.....
https://www.youtube.com/watch?v=I4GjY2NxXto

Got my one from Ebay/China and worked just fine

[MagicalArmchair]

Thanks Florian - look forward to that one. I might take the panel off next time I'm down so I can fix it in the bat cave.

I've unboxed the new elbow, and it looks very well made indeed.



It comes with a metal gasket for the engine, and then a normal gasket. Which way around doe the metal guy go? I guess the nodules sticking out are designed to dig into the gasket?



I'm guessing the metal one goes next to the engine, nodules out, then the gasket?



Or, nodules towards engine? Which makes less sense...



And I presume you smear all gaskets with this jazz?

[MagicalArmchair]

I spoke to the awesome chaps at https://www.parts4engines.com/ and they answered those questions wonderfully:

• Only use ONE of the gaskets, you don't need both. The one they supply is composite (the grey one), the metal one is supplied by the manufacturer; Parts4Engines supply their own one to limit galvanic corrosion (given some photos I've seen, that's not a bad plan), so I'll use that.
• The Hylomar is supplied for the water pipes and not the gaskets. The gaskets are dry fit.

Anything else I need to consider on fitting?

[diverphil]

hi, regarding the tacho, there is lots of info on here or on the web, i did mine in September, got the LCD from AK speedo, £20. on their web page look for 'vdo lcd pixel repair' in the top black header. easy job, tested and works but not been back to fit to boat due to restrictions 

[MagicalArmchair]

I took the stainless elbow down and, heeding the advice here, studied the surface of the heat exchanger carefully, congratulating myself that it looked pretty damn good...



...until I realised that was the old gasket... on taking that off I was greeted with this horror:



I had thought it was blowing from the bottom of the elbow, the above backs this up - galvanic corrosion had eaten through the bottom of the exchanger, and around the mated surfaces!



Once cleaned up, we have the below:



The good news it, it hasn't eaten through to the engine. How on earth do I fix this? Take the heat exchanger off and take it to an engineering shop to fill that in?

[Brian]

I had exactly the same problem on my D2-55.  The heat exchanger is made of an alloy and very difficult to repair.  My only solution was to buy a new heat exchanger or find a second hand unit.  Luckily I was able to track a secondhand unit down and get it refurbished, this still cost me a substantial amount but considerably less than a new one.

[Markus]

The good news it, it hasn't eaten through to the engine. How on earth do I fix this? Take the heat exchanger off and take it to an engineering shop to fill that in?

Before taking it off and replacing the whole thing, I wonder if it would make sense to clean the area completely with a dremel or similar to bright metal and use JB Weld or similar epoxy to fill the whole corroded area up to the original sealing flange. You could probably use release paper and a blind flange to make the epoxy flush.  It would for sure be a quick fix but not sure if it would be a permanent one...

[markleuty]

Before taking it off and replacing the whole thing, I wonder if it would make sense to clean the area completely with a dremel or similar to bright metal and use JB Weld or similar epoxy to fill the whole corroded area up to the original sealing flange. You could probably use release paper and a blind flange to make the epoxy flush.  It would for sure be a quick fix but not sure if it would be a permanent one...

This is what we did. It seems to be holding together OK. I can't remember how many engine hours we have done since the fix, but it has been there a couple of years now.

[MagicalArmchair]

The good news it, it hasn't eaten through to the engine. How on earth do I fix this? Take the heat exchanger off and take it to an engineering shop to fill that in?

Before taking it off and replacing the whole thing, I wonder if it would make sense to clean the area completely with a dremel or similar to bright metal and use JB Weld or similar epoxy to fill the whole corroded area up to the original sealing flange. You could probably use release paper and a blind flange to make the epoxy flush.  It would for sure be a quick fix but not sure if it would be a permanent one...

I could do that with the heat exchanger in situ, without needing to remove the studs etc - that's a cracking idea... so long as it doesn't crack... I wonder what kind of temperature the repair would subject to in that area? This stuff says it will survive up to 230 Degrees Celsius.

https://www.jb-weld.co.uk/highheatep

[geoff]

I did a similar but smaller repair on my md22 using car silencer repair paste Gungum from memory  . Very sticky and high temperature no problem. I did it a couple of years ago. Geoff

[Laysula]

It looks like there is enough metal left to take the heat exchanger off, remove the studs and have it machined down flat.

[MagicalArmchair]

Hello Laysula, I think it's gone a little too far at the bottom here:



Geoff, thanks for the update. Have you had the elbow off again to inspect the repair since your did it?

• Get hold of some of this jollop (HighHeatEP | JB-Weld), good to 230 degrees C.
• Grid the areas back with a dremel to bright metal.
• Build the eaten away areas back up.
• Use a blind flange with release film on it to make the mating surface nice and flat and squish the goo in. Bolt that guy down, allow to set.
• Remove blind flange.
• Tidy up and grind down any overage.
• Keep a weather eye on it, remove next season and check thoroughly.