Volvo Engine Rebuild ?

[svcattales]

Correction on valve clearances. Shop manual calls for .20 mm and service bulletin .50 mm. Actual adjustment was .50 mm.

[Ex-Calif]

Originally Posted by svcattales

So what does it all mean? I'm thinking a burned valve or a blown head gasket. The head gasket might explain the high level of coolant metals in the oil test. What do you think? Time to remove the cylinder head?

If you use a differential pressure tester you can hear the leak by in the exhaust/intake - indicating valves, or the breather indicating rings.

Basically you use shop air or bottled air across a precise orifice. A pressure gauge upstream and downstream of the orifice indicates pressure drop in the cylinder.

Leakage in this continual flow system can be heard.

If you aren't into doing that I would pull the head first.

[svcattales]

I pulled the head off and one of the valves in #2 cylinder was definitely bad. The machined surface of the valve was heavily pitted and so was the seat. Additionally, the cylinder head was heavily pitted above the # 2 piston and so was the top of piston. There was also lots of oil caked on top of the piston, cylinder head, and in the exhaust manifold of #2. (see pics below). As a minimum I need a valve job with at least 2 new valves.

I'm concerned about the heavy pitting on the cylinder head particularly around the valve seat. Do you think the head is salvageable from what you see in the pics?

The cylinder wall of #2 looked like it was in good shape and there wasn't any ridge at the top of ring travel. I will try to find a micrometer to see if cylinder diameter is within tolerances. The head gasket also looked good and I didn't see any rusty spots to indicate anti freeze leaks.

Any ideas about what would cause the heavy pitting of head in #2 cylinder? The oil analysis showed high levels of sodium & potassium which indicates antifreeze in the oil. Maybe coolant got in #2 cylinder?

[never monday]

If I were stuck on an island with limited resources, mid ocean. I'd consider reusing that head. Otherwise, it's trashed.

That engine suffered a sea water reversion

[svcattales]

Originally Posted by never monday

If I were stuck on an island with limited resources, mid ocean. I'd consider reusing that head. Otherwise, it's trashed.

That engine suffered a sea water reversion

Thanks Never Monday. I was afraid the head was toast. Is "sea water reversion" caused by seawater backflushing through the exhaust system or perhaps a blockage in exhaust elbow?

[never monday]

Originally Posted by svcattales

Thanks Never Monday. I was afraid the head was toast. Is "sea water reversion" caused by seawater backflushing through the exhaust system or perhaps a blockage in exhaust elbow?

either or both...how does the elbow look? It may just have sat for a long time with that exhaust valve open in a "salty air" enviroment.
I'm sure the next question is why is the cylinder wall ok. All I can guess is the piston came to rest at the top of the bore. This would be BDC for that cylinder.

[Ex-Calif]

That #2 piston do't look so great either. You guessed this engine had over 5,000 hours on it.

You are likely now facing buying a new/rebuilt head vs. just ovehauling the one you have.

Now is the tough call to do the bottom end and have the whole engine done.

As Nm says the cyclinders don't look too, too bad but you have the engine open this far already....

[DeepFrz]

I noticed in picture #5 that your wiring harness is pretty much shot.

[never monday]

Originally Posted by DeepFrz

I noticed in picture #5 that your wiring harness is pretty much shot.

that just looks like the jacket Volvo uses

[svcattales]

Originally Posted by Ex-Calif

That #2 piston do't look so great either. You guessed this engine had over 5,000 hours on it.

You are likely now facing buying a new/rebuilt head vs. just ovehauling the one you have.

Now is the tough call to do the bottom end and have the whole engine done.

As Nm says the cyclinders don't look too, too bad but you have the engine open this far already....

Ex-Calif, are you a mind reader? Now that the heat exchanger, water pump, alternator, head is off should I continue the bottom end and do rings, bearings and replace the #2 piston?? If I can rebuild the bottom in place, the job won't be too difficult. If I have to remove the block for boring then it gets a lot harder... very heavy; will it fit out the hatch?; moving block from boat to dinghy to dock to truck etc. Yikes, one oil sample has turned into a full time job.

[barnakiel]

Well, why not open and investigate the condition of the bad apple?

I would. 2030 are not the best of Volvos but at least you can still get all components.

Open the engine and check the internals, then calculate the cost of replacing the worn parts vs. the cost of a new unit. I have seen the owner replace say everything on cylinder No 1 only to see the same issue crop up on No 2 a bit further down the road.

I am a bit surprised the oil interval at 140. Is it so by the book? Asking because on our MD7 we replace at 50 when not sailing and towards 100 when in heavy use. Filters every second change. Engine from 1980 and still OK on the original set of parts.

b.

[svcattales]

Originally Posted by never monday

that just looks like the jacket Volvo uses

True. Wire is fine, jacket needs some electric tape.

[svcattales]

Originally Posted by never monday

either or both...how does the elbow look? It may just have sat for a long time with that exhaust valve open in a "salty air" enviroment.
I'm sure the next question is why is the cylinder wall ok. All I can guess is the piston came to rest at the top of the bore. This would be BDC for that cylinder.

NM, I've been having lots of elbow problems. When I bought C.T. 5 yrs ago the elbow was causing overheats due to severe constriction. I replaced elbow and it ran fine for several years. On our last cruise we had cooling seawater leaking around heat exchanger rubber caps into the antifreeze. I think part of this problem was due to restricted flow of elbow. (I just installed new S/S elbows on both engines and you gave me great inputs on the design)

I like your theory of "salty air" causing the pitting with exhaust valve open and piston in full up position. Darned the luck. We normally sail in the winter, so the boats sits in hot/humid Florida weather tied to the dock. I normally run the diesels once/month, but maybe i need to run them more often.

[Laidback]

Your Reports :-
starboard MD2030B engine burned about 4oz of oil every 10 hours.
#1 was 450psi, #2 was 90psi and #3 was 460psi. It looks like #2 is the "bad apple." I added a tablespoon of motor oil into the injector hole on # 2 and checked the compression again... it was still 90psi.
-----------------
Oil usage
No compression 2nd cylinder
adds up to:-
Rings on Piston need replacing

[Ex-Calif]

Doing the bottom end in situ is possible but but at this point, were it my engine, I would haul the block out, disassemble and install new rings, bearings, a new #2 piston and get the block machined.

You still don't know if something leaked across the head gasket or came in the exhaust port.

You will have the head milled flat but your plan precludes milling the block. Nice and flat mating surfaces would be nice as would new, bearings, rings and a #2 piston.

It is hard to tell in the photo but there does appear to be a streak from the pushrod galley to the #2 cylinder although I could be wrong.

Put it this way. Another $600-$1,000 now and don't worry about the donk for 10 years.