Engine blues - volvo penta

[hirondeller]

Interesting case. I am a 'serious amateur' mechanic.

I owned two Volvo diesel car engines. One blew a head gasket. The symptons I observed were mild overheating and oil in the coolant, I saw black motor oil in the radiator (diesel crankcase oil is black from high compression blowing carbon past the rings, this 'blackness' is unusual in gas engine cars). I saw no coolant in the oil. There were exhaust bubbles in the coolant overflow tank. My compression testing revealed low compression in cylinders #3 & #4. I pulled the head off and did not see any clear indications that the head gasket was bad between #3&4, but, cylinders 3&4 were sparkling clean, (in a 6 cyl diesel) they had clearly been burning coolant and smelled like coolant.

A new head gasket fixed all the problems. There were no cracks in the head or block (look hard for them). My point is that a head gasket failure is not always evident from a visual inspection of the head gasket. Consider a compression test and/or a cylinder leak-down test after re-assembly for peace of mind. Someone did suggest a compression test in the string above, remember that the aforementioned tests will confirm or eliminate a head gasket failure diagnosis, next time consider running them before disassembly. Note that a cylinder leak-down test can be performed on a non-running motor, before re-installation in the boat.

[Tillsbury]

“After 12 years of life time”? My Volvo is 15 years old and I still think of it as basically new

[Ianau]

Assume that you have seen this thread - particularly page 5.

http://www.cruisersforum.com/forums/...ine-23357.html

[Rhythmnblue]

You are describing the same problem we had in August with D1 30.
Heres what we did. Remove exhaust elbow, clean the lower inside lip of the exhaust manifold, ( just inside where the elbow bolts on)
After cleanin the carbon I Dremeled with wire wheel to find a corroded hole olong the lower edge. Bring the aluminium clean then fill with JB Waterweld epoxy. Later you may have it welded. So far 50 hrs no problem.

[SOLAR SUPPORT]

Originally Posted by Tillsbury

“After 12 years of life time”? My Volvo is 15 years old and I still think of it as basically new

You didn't mentioned your VP's model, but I think you have changed the elbow-mixer every year if you run the engine more than 250 hours annually.

Stainless Steel Elbow serves many years with no problem. There are cast stainless steel replicas in the market, which have the same size and look. I didn't buy one. Just bring the old elbow to a stainless steel welding professional and ask him to make it two inch longer outlet than the original elbow. As I mentioned in my previous post, I replaced the cast iron elbow on my new engine and I'am very happy with my decision.

The VP engine itself is good but elbow is the source of most problems, like: Overheating, White Smoke, Low Performance, Low rate of turnover. The following picture shows the elbow inlet at 50 hours. You can see the oxidation dispersed.

[verkerkbr]

It looks like a well known problem. If the injection point of cooling water into the exhaust is below the waterline. If this is also possible when the boat heels, then there is the risk of siphoning of seawater in the outlet manifold after the engine is switched off.

It is possible when the impellor of the impellor pump is not completely watertight.

To avoid this problem, on most systems a vacuumbreaker valve is fitted.

But after some time this valve is clogged and does no longer work.

Sometimes it is only a small rubber part.

Replace the valve with a small hose connector to one of the cockpit drains, so that there is a permanent small air intake after the engine is switched off. And if the engine is running a small drain of water is going via this connection.


Bram

[Tillsbury]

Originally Posted by SOLAR SUPPORT

You didn't mentioned your VP's model, but I think you have changed the elbow-mixer every year if you run the engine more than 250 hours annually.

Stainless Steel Elbow serves many years with no problem. There are cast stainless steel replicas in the market, which have the same size and look. I didn't buy one. Just bring the old elbow to a stainless steel welding professional and ask him to make it two inch longer outlet than the original elbow. As I mentioned in my previous post, I replaced the cast iron elbow on my new engine and I'am very happy with my decision.

The VP engine itself is good but elbow is the source of most problems, like: Overheating, White Smoke, Low Performance, Low rate of turnover. The following picture shows the elbow inlet at 50 hours. You can see the oxidation dispersed.

It’s a TAMD22, but it has the original elbow, although I did give it a serious clean out and renovate last year. I understand that the stainless steel ones aren’t necessarily a panacea, as they introduce other mixed-metal issues you need to be careful about.

[SOLAR SUPPORT]

If you take a look at the first post send as topic by the member Manana5, VP model d1-20 is the subject. The elbow I'm talking about is used with VP's D1-20/30/40 models that has no turbo charger. You have an other model of VP engine that its elbow was attached to a turbo charger.

Mixed-metal issues? Yes certainly an important issue.. if the sea water can't flow from the short and oxidated cast iron pipe channel in the elbow and splash back towards the aluminium exhaust manifold..

For me, It is not enough to make it with 316 CrNi stainless steel, It is necessary to make this elbow a little bit longer to avoid harmfull sea water coolant splashes.

[Michael Graham]

Thanks drcat. I wish I had heard of them earlier.

We had an engine problem on our D1-30 on an Atlantic crossing and this forced us to stop in the Azores (highly recommended) where the problem was a cracked cylinder head. In fairness I must say it was a problem caused by the boat builder's new plumber fitting a vacuum breaker on the fresh water line!

The local agent quoted us Euro 4100 for the cylinder head and I managed to buy it at home for E 2800. When I contacted Volvo to complain about the price disparity they sent a one line reply that "They didn't interfere with Agent's pricing!"

I also had to wait four months for the part to be manufactured in Japan as they didn't carry stock!

The engines have worked perfectly since then.

Thanks

[T Greening]

I may have an idea of how this started. You mention that you were in a fairly lively sea when the engine first over heated. I have had this happen to me on a Sigma 38 and a small Westerly. If the salt water cooling sea cock is positioned either to the side or rear in these conditions the engine picks up air. Most impellers will not purge the air, so you over heat. Some boats just will not motor sail, as soon as you heal over its game over !
The rest is engine damage, you could try just a new head gasket but I would suggest that you should get the head skimmed first.

[Manana5]

Originally Posted by Tillsbury

“After 12 years of life time”? My Volvo is 15 years old and I still think of it as basically new

True, we think of our engine as "new", especially considering the boat itself is 45 years old

[Manana5]

Originally Posted by SOLAR SUPPORT

If you take a look at the first post send as topic by the member Manana5, VP model d1-20 is the subject.

Yes, this was my first post when the engine was just overheating sometimes and we were wondering why. Since then, issues escalated so I opened this new thread.

[Manana5]

I want to post a little update as we finally discovered what the problem was.
We took apart the engine head and did not observe any damaged gaskets or other visible damage. We then took the head to a professional shop to test for cracks - none were found. Finally we tested the heat exchanger for leakage by plugging all the out-holes and pouring water from one end - it leaked where it shouldn't have, although no visible holes were found. We took it apart, soaked in sodium hydroxide solution, scrubbed and cleaned some more. And this became visible:

[SOLAR SUPPORT]

Originally Posted by SOLAR SUPPORT

After 12 years of life time, my sailboat's engine was replaced with the New same Volvo Penta engine because of expensive parts and labour.

Volvo Penta's D1-20/30/40 have the same exhaust elbow, mixer. Original elbow is made with cast iron which can corrode very fast as the salty water passes through it and mix with the exhaust gas. I have replaced my new D1-30's elbow with a 316 stainless Steel elbow. I Just made the elbow like Yanmar's.

I believe that cast iron is not a proper meterial to be used for the elbow. It is corroding very fast and the salty water can't pass laminar through the pipes within the elbow. As a result, salty water splash back to the exhaust manifold which made from aluminium. Salt deposits build up at the exhaust manifold and elbow juncture in time. Usually at this point Salt water and different metals wear themselves because of the galvanic corrosion.

After I demount the elbow from the exhaust manifold, I cleared a handful of these salt deposits at the juncture and saw that the alimunium was melt at this point causing fresh water and antifreeze mixture leak from the cooling system. I was Lucky because the leak started when I start to clean the salt deposits. It was very close to leak into the exhaust manifold and then to the piston heads through the exhaust passages.

Picture shows the tiny hole at the D1-30's exhaust manifold outlet that was made by galvanic corrosion.

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.

[Rhythmnblue]

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