Hi all. We have a Volvo Penta MD17C engine with overheating problems and we're stuck on the Sacramento River on our way to SF Bay. We suspect salt buildup in the water jacket maybe? Very little water coming out in exhaust. It seemed fine in the morning and decreased significantly at the time we stopped.  Wondering first if a vinegar or miriatic acid flush is worth a try to improve things enuf to continue, and if it's safe to try.  Engine survey 2 years ago said temps on the high side and that the heads would soon need to be removed and serviced. Trip up the river 1.5 years ago was fine, ran at 1300rpm with normal temps.  Very little use since then as we were on the river. Before that it was in ocean water most of it's life. Raw water cooling system.

We noticed some higher temps on a little shakedown trip before heading down river and had a mechanic look at it. He used IR sensor and declared it was likely a bad sender, changed that out and got same gauge readings so he said probably gauge was off because temps were fine. We got our own IR gun for the trip. Temps  slowly got hotter and hotter all morning and we quit at 190. At that time we noticed that a siphon tube with a T that entered the cockpit drain was squirting water in there (and steaming)... Is that normal? Still see squirting this morning at cool temps (no steam, however).

We had a new impeller that we then installed, but no change to flow of water out the exhaust after swap.  

Any thought/suggestions? Also for towing or yards/mechanics in the area? We have a mechanic coming in the morning but I don't know if there's anything he can do or even if the head can even be pulled with boat at a dock. Older Westsail 32 hull #082, so cockpit floor not removable. Most of trip is upwind in narrow channel with currents, can't rely on sail.

Sorry if I we don't respond to all suggestions--limited time and typing ability right now. Thanks!

Andrea and Mike

Charles has a good suggestion there. I have the MD11C and run muriatic acid through the engine occasionally through a bypass hose attached to the sea water intake with a bronze T fitting. The reverse gear cooling jacket can also cause a problem if it is clogged. You can remove the hoses and drain plug and clean it out somewhat with a coat hanger. There is a small orifice located behind the thermostat that has a tendency to get clogged as well. If so, then the thermostat will not open. You might try running without the thermostat to get you out of the river although as I recall, some type of gasket will have to be fashioned to seal the housing properly without  the thermostat in place.

Good luck

Werner

My original MD2B (raw water cooled) had a water passage in the transmission for cooling.  

The plumbing was designed so the water was drawn through the transmission before the water pump and then pumped through the engine.  (If I recall correctly)  

When I removed the water lines to the transmission. The passageways in the transmission were blocked 95%.   

I soaked the transmission passage way with muratic acid (bad stuff) and also replumbed the water system so the water pump pushed the water though the transmission then to the engine.  That solved the overheating for me -- as did the Beta 35hp replacement a few years later. 

Another way to test is to loosen the coolent hoses at each fitting one at a time until they leak and see where the flow is blocked.  (Better if you do this in the Delta with "fresh" water). 

Do let us know how it turned out and welcome Westsail sailing on the SF bay! 

Jay 

Pygmalion W32

Alameda Marina