15 bolts later

[team karst]

i have the thermostat in my hand on a Volvo MD2030. This is an engine small enough you can wrap your arms around in any direction. wow.....

Who do I blame for this engineering travesty; the English, French, or Japanese?

Oh; these are just the fasteners for the actual water pump. To get there you need to fool with other stuff, like the alternator, the pump pully, and some hoses. Make it 20 fasteners total.

[Pete7]

Is that the one you have to take the exhaust manifold off to reach the thermostat

[jimbunyard]

What have the French to do with it? Believe Volvo is Swedish.

Anyway, blame the English. They're the ones who marinized (or had the Japanese marinize) the Japanese-made ISM multiuse engine.

Really good engine nonetheless.

[team karst]

Originally Posted by Pete7

Is that the one you have to take the exhaust manifold off to reach the thermostat

No, those are the smaller 2010, and 2020 models. Lots of fun there too, i''ll bet.

[team karst]

Originally Posted by jimbunyard

What have the French to do with it? Believe Volvo is Swedish.

Anyway, blame the English. They're the ones who marinized (or had the Japanese marinize) the Japanese-made ISM multiuse engine.

Really good engine nonetheless.

Ur, right. Not French. French boat, and I'm cussing them out too.

Overheating at WOT. New RW pump didn't fix it. OK up to 2500rpm. Exh mixer shoots cool at 140 deg. There was a small passageway inside the pump that was clogged. My new thermostat opens in hot water same as old... THe hose fitting to the water heater was clogged. The heat exchanger was replaced at some point, the tubes claim to be fairly new. When I shoot the HE with the ir gun, it reads just 180, whilst the water pump was at 210, during the alarm. So, I was thinking limited coolant flow. And, very low steam levels out the exhaust. The oil filter read same as other side engine at 205 deg F.

[hpeer]

Perchance an air leak under higher suction at high rpm??

Had that issue on a Volvo MD7 with their silly copper tube connections. Took the devils own tine to figure it out.

[team karst]

RW air suction leak? That’s possible and i’ll check that.

[skipperpete]

Apparently Caterpillar US now owns Perkins.
14 bolts and just to raise the bar a notch ... one long stud that locks itself in with corrosion at slightest hint of a coolant leak.
I encountered an overheat issue on an NL genset ( same core engine) that had been overhauled, ok with no load but as soon as full load was on the overheat alarm would trip the shutdown. The overhaul guy had put the thermostat in back to front and there was just enough water through the bypass to keep things manageable at 1500...... until loaded up. Even loaded, the overheat came fairly slowly because I guess that even wrong way about, the thermostat itself got hot enough to partially open.

[jimbunyard]

Originally Posted by team karst

Ur, right. Not French. French boat, and I'm cussing them out too.

Overheating at WOT. New RW pump didn't fix it. OK up to 2500rpm. Exh mixer shoots cool at 140 deg. There was a small passageway inside the pump that was clogged. My new thermostat opens in hot water same as old... THe hose fitting to the water heater was clogged. The heat exchanger was replaced at some point, the tubes claim to be fairly new. When I shoot the HE with the ir gun, it reads just 180, whilst the water pump was at 210, during the alarm. So, I was thinking limited coolant flow. And, very low steam levels out the exhaust. The oil filter read same as other side engine at 205 deg F.

Well, logically, simplest first, I'd assume trapped air in the freshwater side, though the reversed t'stat is worth checking.

Moving on from there, I'd guess something's wrong with the raw water/freshwater interface; typically the two most common things are a raw water obstructed mixer/riser, or bad sealing around the H/E boots, which allows raw water to mix with freshwater. The sealing surfaces around the H/E bundle and the H/E housing must be clean and scale free, make sure that there is no scale stuck onto the boots themselves. The bundle itself should be place equadistant within the housing, and it should be situated so that the comparatively small hole should be facing up, whilst the large hole should be facing down.

The low temp of the mixer would lead me to believe that that's not the problem, but if I had to guess and wasn't told about that low reading, I'd say that the problem was a clogged/corroded raw water jacket in the mixing elbow/riser.

High temps at WOT are, in my experience, more often caused by overpropping or overloading or fouling. Have you had any incidents that would change any of the final drive configuration, and have you checked for excessive growth or fishing line around the shaft/drive?

[team karst]

There is no change in coolant level in the overflow tank, and yes, dove the rig last month. Clean and no fishing line. WOT is 3200 on each motor. There is some light/white smoke/steam from each exhaust at high power settings. Nothing black/blue.
I'm putting it all together today; i did take off the separation plate behind the pump to look for more debris, clean in there. That inner gasket was $34.
Nice having two identical engines; makes it easy to compare using the IR gun.
If no joy with this last attempt, will replace the exhaust mixer. I have a SS one to try.
Spring side of the 'stat towards block.
Gosh; maybe with enough 3/4" hose, I can have the port and stb engines run with the other sides RW pump/strainer/saildrive pickup.

I"m also wondering how the water tank feed works. Is this bypassing the HE? Or, in series with the block coolant? Of course, the other engine has the WP ports plugged for the remote water heater, but that maybe is better for the engine cooling?

[jimbunyard]

Originally Posted by team karst

...That inner gasket was $34....

Gosh; maybe with enough 3/4" hose, I can have the port and stb engines run with the other sides RW pump/strainer/saildrive pickup.

I"m also wondering how the water tank feed works. Is this bypassing the HE? Or, in series with the block coolant? Of course, the other engine has the WP ports plugged for the remote water heater, but that maybe is better for the engine cooling?

Good lord, get a gasket paper assortment and learn to make your own gaskets...

If worse comes to worst, you could run a hose from the 'properly' working engine; even garden hose would be sufficient for testing purposes. I certainly wouldn't go to that extreme just yet.

Forgot to mention that the orientation of the HE bundle is very important; the small 'bleeder' hole really needs to be facing up, the large hole really needs to be down.

More importantly, I'm really leaning toward an air lock or trap on the freshwater side. If by 'water tank' you mean water heater, the only ones I've ever seen use freshwater (engine side) to heat shower water. Usually the inlet and outlet are at the front of the engine, somewhere in the vicinity of the t'stat.

It is extremely common to get air 'traps' into the F/W system when working on that system when a water heater is present. Look for loops in the hose runs that could hold or trap air, and figure out a way to purge the system.

You might be able to loosen a fitting at a high spot, or something along those lines, or, it you have some kind of small pump (a little bilge pump in a bucket?) you could remove the heater supply and return lines and recirculate the coolant (heatant?) until you get an air free flow...

[team karst]

Can i view the small hole or large hole by just removing the rubber hose fittings? Both ends need to come off?

[jimbunyard]

No the bundle must be removed because the holes are in the center. Also, this only applies with some bundles, seems I remember seeing some that are not 'enclosed', but are just a bundle of tubes.

Usually, the original VP one is shrouded in a tube, many aftermarket ones are just the bundle of tubes.

You might want to have a look at this thread, the first picture shows the bleed hole that should be facing up. There's a large hole, about an inch and a half, directly opposite that should face down.

https://www.cruisersforum.com/forums...er-172541.html

[laird]

Originally Posted by skipperpete

Apparently Caterpillar US now owns Perkins.

Correct the Perkins factory is a few miles away from.Where im.sitting , it has a big sign outside that says Caterpillar , they manufacture Volvo engines there and Perkins too

[team karst]

My tube bundle has visible tubes, as seen from the coolant fill hole. Very likely aftermarket. I'm not sure why one would shroud the tube bundle. Seems odd.