www.iFourWinns.com

Took the boat for run to grab some lunch with friends. The engine alarm sounded but the gauges all were normal (I have a new engine temp sensor). We open the engine cover and there is a little steam/smoke on the port side.

We touched the manifolds/risers and the starboard side was warm but you could lay your hand on it and felt normal and no steam/smoke. The port side was too hot to touch and hold your hand there. (These are brand new manifolds and risers).

We disconnected the water line to that runs from the top of the engine to the starboard side (see picture) and very little water came out. Started the engine for a second and a little dribble of water came out. We blew in it and wiggled it around (could not get it loose at the top of the engine to flush it completely as we were out on the water) and when we started it for a second water flowed.

After reconnecting, it ran fine at about 28 mph. If we pushed it up to 38 mph for an extended period of time, it re-occured. So we kept the speed down and it ran fine.

Friend and I were thinking the thermostat might be clogged or not functioning and the hose could have some obstruction. I posted a picture. Is the thermostat where I showed it? Also does anyone know (1) part number for thermostat (2) part number for the hose?

Thanks

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2010 Sea Hunt Triton 220 "Big Whiskey"
2003 FW Freedom 180 Volvo Penta 4.3GL/SX-M "It'll Do Four Now" (Sold)
2012 Avalanche LTZ 4X4

Can't speak directly about the VP as I have a Merc, but I had this same issue this summer. Replaced the thermostat and everything cleared up.

Yes that's the thermostat housing. It comes off with 2 bolts, you will need a new gasket, new thermostat if you want to replace it, there is a rubber ring that holds the thermostat in place. Usually the rubber ring can be re-used but pick up one just in case. Also you need some non-hardening gasket sealer like OMC/Bombardier gasket sealer.
I'd remove the housing and then remove the 'stat by prying out the rubber ring with a small screwdriver. You can test it in a pot of boiling water suspended with a wire, it should open at 160* and be fully open at about 180. About your manifold heating problem, it might not even be the 'stat, it could be a clogged port on the side of the thermo housing feeding the hose that leads to that manifold. Check all the ports in the housing, you can rod out the openings with a coat hanger.

When you reinstall, put the new thermo in, so the spring faces down when the thermo housing is in the installed position, work the rubber ring in the groove that holds it. Coat the gasket on both sides and the threads of the bolts in gasket sealer and tighten the bolts, replace the hoses and check it out again.

Just another thought, when was the last time your impeller was replaced?

The way the water flow works with these, is with a cold engine, thermo closed, the water from the impeller goes straight out the manifolds. Then when the thermo opens, the hot water from the engine exits the thermo housing, and mixes with some of the cold water coming from the impeller and then exits through the manifolds.

My old OMC uses the same exact thermo housing design, and Volvo adopted it during the joint venture years with OMC, so most modern Volvos use an OMC designed thermo housing....

_________________
88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

As a test, for what it is worth! Take the old thermostat and put in a pan of hot water. Use a kitchen the thermometer to see when it opens. This will tell you if its bad or not.

I think you mean you disconnected the hose on the port side.

I thought that cold water from the pump always goes directly to the manifolds and risers? The thermostat only allowing cold water into / hot water out of the engine as required ? If you look closely at the photo, the hose from the raw water pump is adjacent to the outlets to the manifolds.

As only one side is affected, it sounds like a blockage in the outlet on the thermostat housing or inside the hose itself; the ID of those cast iron spigots on the thermostat housing is not that big, there may well be rust flakes or even the remains of an old impellor blocking it or the hose ( the inside of the thermostat housing on my first 5.7 was very rusty indeed after 6 months use in salt water; BIG flakes of rust in it. I fitted closed cooling before the next season !).

As a matter of interest and nothing to do with the problem, , what are those hoses going from each riser to underneath the carb cover. For the Thermostatic choke ?

Graham

It doesn't sound like a thermostat issue at all to me....as posted already - the therm only controls water flow into engine to manage temp of engine. The water supply to the manis should be constant and not controlled by thermo.

Sounds like you do have a blockage - could be at the yoke of the therm housing if that's where the water feed to the manifolds connects. Mine connect there, but yours may be different.

Couple points - when did you last swap out the impellor? If not within year then start there and change it....are any fins damaged on impeller? If so i bet that's what is stopping up the system. You can check the connection points for the hose to the mani's and the hose itself...from there i would remove the riser and inspect and clean any debri - remove the mani drain plugs, probe the holes and flush.

Also - if you have debris in port side....i would do the same to the starboard side cuz chance debris may be there too....

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http://i1339.photobucket.com/albums/o71 ... wqm355.jpg


08' H210SS
VP 5.7Gi

In my OMC manual, they have a test for the thermo, without removing it. When you start the engine, the hoses to the manifolds will be cold, with a closed thermo. When the thermo opens, the hoses are supposed to warm up, if not it's sign of a sticking open thermo. I checked by had and there is not too much of a difference, but the IR heat gun does show they get hotter with a warmed up engine, so some hot water from the block does mix in.

_________________
88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

Thanks guys. Work got in the way and I did not get emails that there were responses.

The manifolds and risers were just replaced about 2 months ago.

Impeller was done in April.

I think I am going to start with looking for the blockages as the old impeller was missing some little pieces when I changed it and water flow kept changing when we disconnected it on the water.

Yes, the hose we disconnected (port side and marked in picture above) is connected right to the thermostat housing. You cannot see it because the alternator is in the way.

Going to tackle it this Friday/Saturday as we are going to a holiday boat parade Saturday night.

Thanks

_________________
2010 Sea Hunt Triton 220 "Big Whiskey"
2003 FW Freedom 180 Volvo Penta 4.3GL/SX-M "It'll Do Four Now" (Sold)
2012 Avalanche LTZ 4X4