I am having engine cooling problems with my Columbia 8.7 with a 15 HP Yanmar diesel engine. When I start the engine at the dock, I get good cooling. I motor out into the York River/Chesapeake Bay and shut the engine off to sail. When I am ready to come back into the marina, the water pump is not pumping any water, and if left unchecked, the engine will overheat. Initially I thought I had a restriction in the seacock, but I checked it and have good water flow. If I shut the engine down and let it set for a couple minutes, then restart it, I get water flow out the exhaust and good cooling. While the engine is shut down, I make no other corrective actions. This only happens when I'm coming back into the marina. It never happens on the way out. Sounds strange, but that's what I've observed. The only difference I can think of is that at the marina I have the seacocks closed and open them just before I start the engine. After sailing, the seacocks have been open for several hours. The water pump sits below sea level and should have a flooded suction. I rebuilt the water pump over the winter with a new impeller, new seals and a new shaft, but today I had the same problem. Has anyone else ever heard of such a strange situation? Anyone have an idea how to correct it?
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Very Interesting. You didn't state whether or not it was fresh water cooled, but since you stated you had just rebuilt the pump, I would start there. Could the pump body be warped slightly, and when it gets a little warm from enging heat allow the gasket to loose it's seal. The same thing for the shaft seals. But it is rather strange.
Very Interesting. You didn't state whether or not it was fresh water cooled, but since you stated you had just rebuilt the pump, I would start there. Could the pump body be warped slightly, and when it gets a little warm from enging heat allow the gasket to loose it's seal. The same thing for the shaft seals. But it is rather strange.
Yes
Jim, Yes, I had the exact same problem. The short solution is to keep the seacock closed at all times whenever the engine is not running. Your pump is still probaly worn out somewhere - perhaps the cover is not seating properly due to wear. That small bit of air will cause the pump to lose prime. I opted to just buy a whole new pump and the problem was solved. Good luck! Rob
Jim, Yes, I had the exact same problem. The short solution is to keep the seacock closed at all times whenever the engine is not running. Your pump is still probaly worn out somewhere - perhaps the cover is not seating properly due to wear. That small bit of air will cause the pump to lose prime. I opted to just buy a whole new pump and the problem was solved. Good luck! Rob
Thanks for response
Rob, Thanks for your response. I guess I'll have to spring the $330 for a new pump. I just wanted some assurances that would in fact solve the problem.
Rob, Thanks for your response. I guess I'll have to spring the $330 for a new pump. I just wanted some assurances that would in fact solve the problem.
another possible solution
I've had problems several times with overheating. One time it was the riser on the exhaust. The engine must get to a certain temp to burn off the residue of the diesel, if it does not the riser gets coated and eventually obstructed by gunk. Had to replace it this last time. Once also was grass in the thermostat, was an easy fix after I traced the water lines and made sure all were clear. Plastic junk and mud can also clog the lines as well as the exhaust system. Would suggest you run through the water lines one at a time and make sure everything is clear before spending a bunch of money on new parts.
I've had problems several times with overheating. One time it was the riser on the exhaust. The engine must get to a certain temp to burn off the residue of the diesel, if it does not the riser gets coated and eventually obstructed by gunk. Had to replace it this last time. Once also was grass in the thermostat, was an easy fix after I traced the water lines and made sure all were clear. Plastic junk and mud can also clog the lines as well as the exhaust system. Would suggest you run through the water lines one at a time and make sure everything is clear before spending a bunch of money on new parts.
Columbia 8.7 Overheating
I had a lot of trouble with overheating in my 8.7 out of Rock Hall. Symptoms same as you described. It turned out to be due to restricted seawater flow due to a rust colored sediment that collected to a brass elbow attached to the riser. Just for kicks, disconnect the hose and turn the elbow out of the riser. Look at it first, and if sediment has collected, just run a wire through it to clear the sediment.
I had a lot of trouble with overheating in my 8.7 out of Rock Hall. Symptoms same as you described. It turned out to be due to restricted seawater flow due to a rust colored sediment that collected to a brass elbow attached to the riser. Just for kicks, disconnect the hose and turn the elbow out of the riser. Look at it first, and if sediment has collected, just run a wire through it to clear the sediment.
8.7 Overheating
Also--with restricted flow due to the elbow clogging--and in more sever case the riser itself, seawater actually gets sucked out of the colling system when the seacock is open and the engine not running while you are sailing. With restricted flow, the water does not fill fast enough to cool the engine when you return to port. So I also resorted to closing the intake when not running the engine while sailing, but that was only relieved the problem, did not solve the problem.
Also--with restricted flow due to the elbow clogging--and in more sever case the riser itself, seawater actually gets sucked out of the colling system when the seacock is open and the engine not running while you are sailing. With restricted flow, the water does not fill fast enough to cool the engine when you return to port. So I also resorted to closing the intake when not running the engine while sailing, but that was only relieved the problem, did not solve the problem.
cooling
Keep in mind that the boat heals. All supply plumbing must have a slope upwards so there is no airlock. (vapor lock). Depending on the type of pump you have it may not be able to overcome the airlock. (Bubble in the line). Shutting the seacocks as someone suggested is an excellent idea. It is concievable when your boat heals air is trapped in the suction line of the pump. You should have a check valve on the sea suction. If there isn't, or if it is not working, you might try that. A proper check valve could keep water from leeching out and keep the pump primed. bw
Keep in mind that the boat heals. All supply plumbing must have a slope upwards so there is no airlock. (vapor lock). Depending on the type of pump you have it may not be able to overcome the airlock. (Bubble in the line). Shutting the seacocks as someone suggested is an excellent idea. It is concievable when your boat heals air is trapped in the suction line of the pump. You should have a check valve on the sea suction. If there isn't, or if it is not working, you might try that. A proper check valve could keep water from leeching out and keep the pump primed. bw
Where do I buy a new Pump
dhoodenpyl@aol.com Looking for parts sources My 1967 has a Palmer p50 gas engine This is the same engine as the International Cub tractor Been using Tractor parts, would love a marine source reply to dhoodenpyl@aol.com
dhoodenpyl@aol.com Looking for parts sources My 1967 has a Palmer p50 gas engine This is the same engine as the International Cub tractor Been using Tractor parts, would love a marine source reply to dhoodenpyl@aol.com
Two possible problems ...
1. the exhaust manifold may be temporarily blocking with large pieces of 'slab rust'. "Slab rust' are large plateletts of rust that break off from the internal casting surfaces and lodge at the outlet of the manifold. When the engine cools and the water stops the slabs fall to the bottom of the manifold ... only to migrate later. To check: when the engine overheats, remove the hose between the manifold and the water injection elbow ... and watch for full flow ... should be about 2 gallons perminute at 2500 rpm (measure with a bucket and stopwatch. If not to that flow, then the manifold needs to be cleaned out. Slab rust is due to allowing the engine 'dry' out during long term storage ... engine internals shouldnt be allowed to 'dry' but should be soaked in a mix of antifreeze, water, and rust inhibitor. 2. Engine is fouled with calcium carbonate scale, use a commercial boiler descaler such as Marsolve or Rydlyme to remove the fouling. If the engine has full water flow 2GPM@2500 rpm then the strongst possibilikty is a salt fouled engine. 3. bad temperature gage or sending unit ... or corrosion on the electrical connection wires.
1. the exhaust manifold may be temporarily blocking with large pieces of 'slab rust'. "Slab rust' are large plateletts of rust that break off from the internal casting surfaces and lodge at the outlet of the manifold. When the engine cools and the water stops the slabs fall to the bottom of the manifold ... only to migrate later. To check: when the engine overheats, remove the hose between the manifold and the water injection elbow ... and watch for full flow ... should be about 2 gallons perminute at 2500 rpm (measure with a bucket and stopwatch. If not to that flow, then the manifold needs to be cleaned out. Slab rust is due to allowing the engine 'dry' out during long term storage ... engine internals shouldnt be allowed to 'dry' but should be soaked in a mix of antifreeze, water, and rust inhibitor. 2. Engine is fouled with calcium carbonate scale, use a commercial boiler descaler such as Marsolve or Rydlyme to remove the fouling. If the engine has full water flow 2GPM@2500 rpm then the strongst possibilikty is a salt fouled engine. 3. bad temperature gage or sending unit ... or corrosion on the electrical connection wires.
Dano ....
Try www.moyermarine.com for Palmer parts. Many of these engines used common pumps, etc. with Atomic 4, Westerbeake, etc. If such a pump is totally obsolete you can most times 'adapt' a standard Oberdorfer pump.
Try www.moyermarine.com for Palmer parts. Many of these engines used common pumps, etc. with Atomic 4, Westerbeake, etc. If such a pump is totally obsolete you can most times 'adapt' a standard Oberdorfer pump.
If it's an Oberdorfer
There is a shoe inside the housing where the impeller goes. If the shoe is worn to much it can cause your problem. It could also be your boat just dosen't want to go home. Try backing all the way to your marina to fool the boat. :>) Fair Winds and Happy New Year Cap'n Dave
There is a shoe inside the housing where the impeller goes. If the shoe is worn to much it can cause your problem. It could also be your boat just dosen't want to go home. Try backing all the way to your marina to fool the boat. :>) Fair Winds and Happy New Year Cap'n Dave
My experience...
When you are on a heal, the raw pump drains out and the pump air locks when back at rest. After a few minuits at rest the air bleeds out and you have water at the impeller again. Pat McCartin Inland Marine Diesel Buford, Ga imd_ga@hotmail.com Columbia Contender owner.
When you are on a heal, the raw pump drains out and the pump air locks when back at rest. After a few minuits at rest the air bleeds out and you have water at the impeller again. Pat McCartin Inland Marine Diesel Buford, Ga imd_ga@hotmail.com Columbia Contender owner.
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