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Qayaq · 15-02-2018, 02:06

On the front of the engine where the anode goes 1/2' square round bronze is, as such an emulsion tube that runs through to the back of the head. the holes in the tube get blocked, causing overheating and bad circulation, exhaust injection elbow also blocks as does the exhaust manifold. Start on the easy stuff first. In this order. inlet not blocked, strainer not blocked or sucking air, impeller in good condition, cam not worn out. no old impeller bits stuck in pump outlet pipe work. Pull injection elbow off, check water passages are clear. check exhaust hose hasn't collapsed causing back pressure. Pull emulsion tube and clean. Pull thermostat check it opens using a kettle of water and a mug, use a temp gun, check passages.Pull exhaust manifold. by parts of internet. Enjoy the learning curve.
RGDS Simon

kmacdonald · 15-02-2018, 02:15

It looks like the exhaust hose to the waterlock is kinked. If it blocks water flow, the RW could back up into the exhaust valves. That would cause a catastrophic engine failure.

**Pete7** · 15-02-2018, 02:28

Quote:

Originally Posted by Qayaq

On the front of the engine where the anode goes 1/2' square round bronze is, as such an emulsion tube that runs through to the back of the head.

My anode is on the starboard side behind the alternator, do you really have one in the front of a raw water cooled engine?

Quote:

Originally Posted by Qayaq

Enjoy the learning curve. RGDS Simon

Quite :-) but it is quite a robust engine and whilst folk whinge about the prices many of these engines and Volvo built a lot, are still going strong, so worth keeping going with a bit of TLC.

Pete

ballvalve · 15-02-2018, 02:47

The VP exhaust elbow does block up after a few years, I swapped mine for a s/s one and now its fine, whilst examining the VP one i thought i would have a go at unblocking it, it literally fell to pieces when i tapped the blockage. I would say these are consumable parts and they will let you down - replace it

Jack Hattingh · 15-02-2018, 08:58

I had similar problem. My engine is accessible from the port side and I could remove the exhaust elbow with ease. I forced out the welsh plugs (round recessed discs for access to the inner areas of the elbow). It was carboned up badly. I cleaned all the carbon build-up out with a long screw driver and hammer but with care. The casing was still in good condition. I fitted new welsh plugs and tapped them in (forcibly) with a fibre hammer. About 4 hours work to do the job and still good 3 years later. Easy peasy, you need not simply throw money at every problem.

deblen · 15-02-2018, 12:51

Quote:

Originally Posted by Pete7

My anode is on the starboard side behind the alternator, do you really have one in the front of a raw water cooled engine?

Quite :-) but it is quite a robust engine and whilst folk whinge about the prices many of these engines and Volvo built a lot, are still going strong, so worth keeping going with a bit of TLC.

Pete

This version of service manual shows an optional zinc anode installed in the front of cyl. head. You will note it was hand drawn. Page 27 of 35
The usual place for the zinc is,as you say,down behind the alternator.

https://www.dropbox.com/s/u3yih5rsa2...anual.pdf?dl=0

The block drain spigot is well hidden behind the starter.

Len

olaf hart · 15-02-2018, 13:01

Quote:

Originally Posted by Jack Hattingh

I had similar problem. My engine is accessible from the port side and I could remove the exhaust elbow with ease. I forced out the welsh plugs (round recessed discs for access to the inner areas of the elbow). It was carboned up badly. I cleaned all the carbon build-up out with a long screw driver and hammer but with care. The casing was still in good condition. I fitted new welsh plugs and tapped them in (forcibly) with a fibre hammer. About 4 hours work to do the job and still good 3 years later. Easy peasy, you need not simply throw money at every problem.

I tried that on my first one, but it fell apart as I cleaned it, the interior casting had turned porous and came off with the carbon crud.

Which leads me to the big question, why does the water jacket jam up with carbon on these things, it should be rust.

There must be some sort of backflow from the exhaust tube back into the water jacket.

Anyone else considered this, or found an explanation?

deblen · 15-02-2018, 14:23

Quote:

Originally Posted by olaf hart

I tried that on my first one, but it fell apart as I cleaned it, the interior casting had turned porous and came off with the carbon crud.

Which leads me to the big question, why does the water jacket jam up with carbon on these things, it should be rust.

There must be some sort of backflow from the exhaust tube back into the water jacket.

Anyone else considered this, or found an explanation?

Olaf. The 2003 elbow has water jackets cast into the elbow.These passages begin at the manifold gasket end. The gasket has oblong holes that match with jacket casting.However,these holes are in the gasket simply because the same gasket is used with an optional 4" riser spacer option & the spacer requires jacket water to pass through it.
If you do not have the riser option,then the water is blocked by the manifold casting itself.
Raw cooling water enters the elbow jackets via a pipe at front of elbow in RW & FW cooled models. RW enters the port side of the elbow jacket,during warm up, in the RW cooled model.
This RW has to fill the jacket passages from manifold to top of riser befor it can run down a jacket passage & enter the exhaust gasses.
This means that RW sits in the lower portion of the jacket without much movement. Carbon from the exh. gasses can back up the injection port & foul the stagnant jacket water before the RW starts flowing eg: during startup,etc.

Explanation of 2000 series cooling Volvo 2003 exhaust elbow removal and replacement. [Archive] - Yachting and Boating World Forums

https://www.marinepartseurope.com/en...-26-11619.aspx

Len

olaf hart · 15-02-2018, 15:24

So why does the water jacket clog up with carbon, not rust?

kmacdonald · 15-02-2018, 16:09

Quote:

Originally Posted by olaf hart

So why does the water jacket clog up with carbon, not rust?

The carbon buildup protects it from rust.

vwkevin · 15-02-2018, 23:00

Hey all,

The mechanic really pulled through today and apparently my problems are resolved. There were a number of issues the worst being a majorly blocked seacock. There was also no raw water strainer which meant that most of the pipes were majorly gunked. Most of the hoses were falling apart internally and the exhaust pipe was bent/collapsing. The exhaust elbow wasn't fully blocked and he was able to clean and reuse it. Anyway, he got that all under control and slapped on a bunch of new hoses and now I should be good to go. I think he's also going to be doing a valve adjustment, installing a raw water strainer, and putting in a better prefilter tomorrow. Cross your fingers for me on my trip, and thanks to everyone who offered advice or support!