Excuse - new owner. A mechanic recently worked on my transmission..said there wasn't a lot of water coming out the back and found that the water was routed back ito the sea water strainer - he put a valve in the pipe and shut it off - he said it was a previous mechanics error. In researching the universal M25 it appears that this was the intended route for the cooling system. Will it damage the engine to run this cool? Temp guage now reads 120'f all the time - Is this because we sail in SCAL? Is it because of the water routing? Is it a faulty gauge? Is there a sequence to test temp sender / temp gauge for error?
- Status
More info
Sounds a little odd. The sea water should come from the seacock, through a strainer if one is fitted, to the sea water pump inlet; out the pump to the heat exchanger, out the heat exchanger to the exhaust water infection nipple, where it cools the exhaust riser, enters the water-lift muffler, and is finally ejected with exhasut gasses - and that's it.
Sounds a little odd. The sea water should come from the seacock, through a strainer if one is fitted, to the sea water pump inlet; out the pump to the heat exchanger, out the heat exchanger to the exhaust water infection nipple, where it cools the exhaust riser, enters the water-lift muffler, and is finally ejected with exhasut gasses - and that's it.
Description is for 5411 engine
Your description matches the 11 hp 5411 diesel water route. After leaving the thermostat it is recirculated back to the raw water intake. The thermostat regulates the ratio of new seawater to heated, previously circulated water. This is a sea (raw) water cooled engine. As a result, the engine spews little water out the exhaust when running cool and the temperature runs around 130 degrees to avoid salt deposits in the block. This engine will produce a steam vapor in the exhaust at times due to the point of water injection in the exhaust system and the small volume of water. This is normal in this engine, but leads observers to assume an overheating engine (not at 130 degrees). Your engine should have fresh water cooling, an exchanger, etc., and where does the water go if its outlet is shut off by the valve?
Your description matches the 11 hp 5411 diesel water route. After leaving the thermostat it is recirculated back to the raw water intake. The thermostat regulates the ratio of new seawater to heated, previously circulated water. This is a sea (raw) water cooled engine. As a result, the engine spews little water out the exhaust when running cool and the temperature runs around 130 degrees to avoid salt deposits in the block. This engine will produce a steam vapor in the exhaust at times due to the point of water injection in the exhaust system and the small volume of water. This is normal in this engine, but leads observers to assume an overheating engine (not at 130 degrees). Your engine should have fresh water cooling, an exchanger, etc., and where does the water go if its outlet is shut off by the valve?
Raw v. Fresh
Sorry, I did indeed describe the seawater route for a fresh water cooled engine, my M25. I don't know raw water cooled systems, so I don't know what valve you are referring to. jv
Sorry, I did indeed describe the seawater route for a fresh water cooled engine, my M25. I don't know raw water cooled systems, so I don't know what valve you are referring to. jv
Thanks for your replies - Are the M25 and 5411 similiar? If valve closed no return loop to sea water strainer...engine runs a little cooler ~ 120'F. If Valve open water does return ~ 125'F (No Load) Should I leave it open or closed???
M-25
The 5411 is cooled by sea water only. Your sea water intake cools the freshwater exchanger as only fresh water circulates in your engine. Different systems. Raw (sea) water cooled engines must run cool so as to not precipitate salt in the engine. Your freshwater system should run much hotter as that is not a problem. The eventual engine temp is a function of your thermostat, not how you regulate water valves. Let's hear from M-25 owners.
The 5411 is cooled by sea water only. Your sea water intake cools the freshwater exchanger as only fresh water circulates in your engine. Different systems. Raw (sea) water cooled engines must run cool so as to not precipitate salt in the engine. Your freshwater system should run much hotter as that is not a problem. The eventual engine temp is a function of your thermostat, not how you regulate water valves. Let's hear from M-25 owners.
M25 Cooling
Jack John's description seemed to answer the original question, which was for an M25. I don't know how the 5411 even got into this conversation. The M25 is fresh water cooled through a HX, the 5411 is raw water cooled. The Universal website may have an engine manual on the site. I know my M25 manual has diagams of both the fresh and raw water cooled engines. try www.marinedieseldirect.com or a Google search for Universal engines. Stu
Jack John's description seemed to answer the original question, which was for an M25. I don't know how the 5411 even got into this conversation. The M25 is fresh water cooled through a HX, the 5411 is raw water cooled. The Universal website may have an engine manual on the site. I know my M25 manual has diagams of both the fresh and raw water cooled engines. try www.marinedieseldirect.com or a Google search for Universal engines. Stu
Too cool
Stu, The 5411 was an example of a diesel engine that must run cool due to raw water cooling. It should not run above 135 degrees. The M25 is freshwater cooled and suggested operating temp is 170 to 190 degrees (no salt to precipitate out). The post stating a running temp of 120 degrees is way below that engine's optimum temperature. Perhaps the thermostat is ineffective due to the mechanic's action or simply a defective thermostat. Certainly worth checking out!
Stu, The 5411 was an example of a diesel engine that must run cool due to raw water cooling. It should not run above 135 degrees. The M25 is freshwater cooled and suggested operating temp is 170 to 190 degrees (no salt to precipitate out). The post stating a running temp of 120 degrees is way below that engine's optimum temperature. Perhaps the thermostat is ineffective due to the mechanic's action or simply a defective thermostat. Certainly worth checking out!
5411 not a M25
Engine actually 5411 - sorry for misleading and thanks for advice. Can I make these assumptions? 1. Mechanic didn't know the engine. 2. Valve he inserted in loop returning water to raw water strainer not necessary. 3. 120'F is too cool - he probably didn't replace Thermostat as he said he did...couldn't show me recipt when I asked for it.
Engine actually 5411 - sorry for misleading and thanks for advice. Can I make these assumptions? 1. Mechanic didn't know the engine. 2. Valve he inserted in loop returning water to raw water strainer not necessary. 3. 120'F is too cool - he probably didn't replace Thermostat as he said he did...couldn't show me recipt when I asked for it.
5411
Steve, from your original post the description matched the 11 hp 5411. This engine is raw water cooled directly from the sea. It runs cool as mentioned before. The return line does properly go to the mixing tee which is at the sea water inlet. No valve is necessary (you still need one to close the thru hull when not aboard...open before running engine). The water is recirculated in this tee back to the engine, thus the water circulating is warmer. The thermostat decides how much is recirculated and how much goes overboard thru the muffler and exhaust. When engine is cool, most water recirculates and therefore little water in the exhaust. A warm thermostat sends more water out the exhaust. The manual states an operating temperature of 135 to 150 degrees. The M25 runs 175 to 190 degrees, but it uses fresh water. Your engine needs the recirculating water to warm up properly and will warm up to operating temps (135 in your area) when under load. We sailed Ventura for 10 years, then went to la Paz, where she runs a bit warmer. Hope this helps.
Steve, from your original post the description matched the 11 hp 5411. This engine is raw water cooled directly from the sea. It runs cool as mentioned before. The return line does properly go to the mixing tee which is at the sea water inlet. No valve is necessary (you still need one to close the thru hull when not aboard...open before running engine). The water is recirculated in this tee back to the engine, thus the water circulating is warmer. The thermostat decides how much is recirculated and how much goes overboard thru the muffler and exhaust. When engine is cool, most water recirculates and therefore little water in the exhaust. A warm thermostat sends more water out the exhaust. The manual states an operating temperature of 135 to 150 degrees. The M25 runs 175 to 190 degrees, but it uses fresh water. Your engine needs the recirculating water to warm up properly and will warm up to operating temps (135 in your area) when under load. We sailed Ventura for 10 years, then went to la Paz, where she runs a bit warmer. Hope this helps.
Need manuals?
Steve, If you want manuals contact Independent Marine Services (310) 391 2457. They are at 11813 Major Street, Culver City, CA which is in your neighborhood. The parts manual is UNI 200138 for the M15, 5411 engine. Has breakout diagrams, parts numbers, etc. About $20. Several diesel sites on the web can provide every part for this engine, especially using the correct part number.
Steve, If you want manuals contact Independent Marine Services (310) 391 2457. They are at 11813 Major Street, Culver City, CA which is in your neighborhood. The parts manual is UNI 200138 for the M15, 5411 engine. Has breakout diagrams, parts numbers, etc. About $20. Several diesel sites on the web can provide every part for this engine, especially using the correct part number.
- Status