Engine blues - volvo penta

[Manana5]

Originally Posted by Rhythmnblue

Get it welded at a aluminium shop. This is what we did.

Yes, this is what we are doing as well. Will update if it works.

[Manana5]

Originally Posted by SOLAR SUPPORT

Read again my post and take a look at the pictures.. The event is the same. Replace your elbow with a 316L Stainless Steel made one.

Yes, same issue! Thanks for sharing again. I didn't get from your post what you did about the holes in the main body? The elbow doesn't look that bad in our case so we won't be replacing it for now. Plus, wouldn't stainless steel next to aluminium cause MORE corrosion?

[SOLAR SUPPORT]

No. They are separeted with a gasket and there is no sea water splash back, if the elbow is made longer than the original one. I changed the damaged manifold. Because I couldn't find a trusted aluminium welding professional.

[Rhythmnblue]

After welding, clean and sand the weld & the whole area. Apply JB Weld (high temp epoxy) to eliminate future corrosion.

[kostasc]

Hi,
same issue i had when i went to first pick my newly bought sailboat.
On a D1-30, radiator water was coming out from a small hole . When i took the part in my hands, i discovered few more...
I went to a welding shop and i have it repaired (welded fill) for 220euro.
The engine had no more than 800 hours, may of them just for charging.

I'm not sure if that gasket is electric good conductor, it seem metallic to me.
I was thinking to replace that gasket with something..i'm not sure what... sealing and stand quite high temps.

When the time will come for the exhaust elbow, i ll surely replace it with a stainless steel one, or i 'll order a custom made.

[SOLAR SUPPORT]

This is the galvanic corrosion. The reason of this is the iron cast elbow next to aluminium exhaust housing. Gasket is the innocent part that has no role in this corrosion event.

The iron cast elbow gets rusted very fast since the salty water and exhaust gas passed through it when the engine runs. It is like puting an iron in to the sea water. Then liquid and gas flow through this elbow become irregular, because of the rust deposits on the gas and sea water flow surfaces in the elbow(mixer). Sea water starts to splash back drops to the aluminium exhaust housing.

When you put two or more different metals like aluminium and iron close to each other in a closed housing and splash some salty water on them, galvanic corrosion occur even if you install a thin gasket between them.

This is a common problem for each Volvo Penta D1-20, D1-30, D1-40 engine. When you look at to Yanmar engine at this point, they use a longer stainless steel elbow instead of an iron cast short elbow. This is the most important differance between the two brands which makes Yanmar more preferable and reliable.

This video shows a tuned 316L stainless steel elbow installation to D1-30 engine of my boat.

https://youtu.be/gwKlZlgI6u8

[Tillsbury]

This is what I don't really understand. I've had three Volvo Pentas (admittedly none of the more recent Dx-xx models), but all of them have had very similar cast iron exhaust elbows as these ones. Between 5 and 25 years old, they've shown bits of corrosion in the elbow but nothing a bit of phosphoric and a wash didn't get rid of. Never seen anything like these horrendous cratering situations. What is it that causes such major problems in these elbows when some engines don't have the problem at all?

[SOLAR SUPPORT]

The same iron cast elbow is being used with D1-20, D1-30, D1-40 VP engines. If your's is different then it might be normal for you to observe any problem with iron cast elbow~aluminium cast exhaust housing's galvanic corrosion.

Since sail drive mount of these series of engines positioned more horizontal to the sea waterline the problem should be seen soon when compared with direct shaft-propeller installations for those have a small angle with the motor and shaft togeather with the sea waterline that makes harder for splashing back sea water drops to the exhaust housing when they were runing.

[kostasc]

That was my initial thought, the water drop/sprayed back, but the design of the exhaust elbow is not allowing that. Raw water is sprayed on the outer part of the inner elbow wall. So the water is present at the end part of the elbow, 3-4 cm before elbow end. If there is always a one way exhaust fume, and no reason for water return, why any drops are coming back?
I ve heard issues with engines just under 600 hours ! so soon to say carbon deposit are blocking exit.
If sea water is the catalyst for this, why not solving the elbow's cooling issues with an external cooling coil (or something like this) and inject water few cm after elbow at a safe distance ?
This is a major fault from Volvo, Perkins, Su... something who designed these engines.

[SOLAR SUPPORT]

There are two pipes within the iron cast elbow surrounding each other. Sea water coolant comes from the heat exchanger being poured in between these pipes to their top at the starting of the closed exhaust housing and elbow joint. The sea water coolant cools the inner exhaust pipe and the joint.

Exhausted gases coming from the runing motor's cylinders exhausted from the inner pipe. The coolant sea water and the exhaust gases ere mixed just four or five cm. after the elbow and exhaust housing joint.

This short distance is not enough when the motor is idling or runing at low rpms specialy when the cast iron elbow gets rusted and leads to nonlaminar flow of both the sea water coolant and the exhaust gases within the elbow. Rusting of the cast iron elbow is being very fast. VP services recommend to check the iron cast elbow each year. If it is cloged then replace it with the new elbow.

By using a different technique to bond longer curved pipes within the elbow like welding rather than casting and using the right material like 316L SSteel, solve this problem. Making longer sea water coolant passage within the elbow guarantee no sea water splash back to aluminium cast exhaust housing. No more galvanic corrosion.

I have used mine 250 hours after the elbow change, even at idle speeds for charging my batteries and at low rpms around 1700 when troling. No problem at all.

[mjmcpo]

Just found this thread while searching for answers as to why my engine had so much corrosion. Have ordered a stainless steel exhaust elbow and having the corrosion welded. Do you think it's possible there was an electrical element adding to the problem?

[SOLAR SUPPORT]

Originally Posted by mjmcpo

Just found this thread while searching for answers as to why my engine had so much corrosion. Have ordered a stainless steel exhaust elbow and having the corrosion welded. Do you think it's possible there was an electrical element adding to the problem?

The sacrifice anode in the heat exchanger units of large diesel engines is not available in VP d1-20/30/40 models. This precaution is to prevent galvanic corrosion that occurs between the copper pipes in the heat exchanger and other metals in contact with sea water. Instead of the sacrificial anode, VP d1-20/30/40 engines have a siphon system that allows sea water to be discharged from the entire installation except the impeller pump and exhaust silencer. In this way, galvanic corrosion between the heat exchanger and other metals is kept to a minimum only when the engine is not running. Under normal operating conditions, there is no contact between the aluminum exhaust manifold of the engine and the sea cooling water.

I had these problems with my VP d1-30 engine for 12 years by changing the original VP iron cast elbow every two years. Now, I have been using my elbow, which is made of SS 316L material, 3 mm thick and five cm longer than the original elbow, for five years. There is no clogging at the elbow, no decrease in engine speed or performance. The same elbow has been used on approximately 30 boats for a long time without any problems.

[deblen]

Originally Posted by kenL

I Have a 2003 Volvo Penta 2030 which is a Perkins Diesel which is marinzed by Volvo for marine applications. I had the exact same problem recently and here is what we found. We first thought that it was the head gasket but after removing the head we discovered that there was fresh water in the cylinders and not salt water. We then removed the heat exchanger Tank and exhaust elbow and found that the exhaust elbow was plugged and there was a hole in the exchanger tank which was allowing the coolant water and antifreeze to back up into the cylinders. Since they don't make the engine anymore the parts were ungodly expensive. 1300. for the exchanger tank, 600 for the exhaust elbow and 450 for the head gasket, water pump gasket and rubber boots on the salt water side of the heat exchanger. All is now fixed and unfortunately $4500 later we are done. When I first bought the boat a year ago I was advised to put a riser loop on the salt water side of the heat exchanger to eliminate any chance of salt water getting into the engine when the boat heels over and the intake is lower than the waterline. You might want to look into that also. Good luck.

Your Volvo Penta MD2030 is built from a Shibaura 103-10 engine. That series of Shibaura was used in several "tractor/industrial" products by various mfgrs.

It is also the basis for Perkins (Prima) M30 marine engine.
Hope this info helps you find more reasonably priced parts/acces. in future. Cheers/Len
https://www.dieselmann.no/files/H%C3...%20Manuals.pdf


https://sbo.sailboatowners.com/downl...__79584434.pdf

[mjmcpo]

Hi, do you happen to have a drawing or design plan for the stainless elbow you fabricated? I'm in the Dominican Republic and found a good welder who can probably make for me. I'm just not sure about the inner cross section. Thanks!