Re: [Amel Yacht Owners] Raw water cooling
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I believe you can flip the plate over and use the other side.
If you have an opportunity get some thumb screws. They make taking the plate off much easier.
Kimberlite Amel Super Maramu #376
From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Saturday, April 01, 2017 10:13 AM
Subject: Re: [Amel Yacht Owners] Raw water cooling
Eric , No , it may well be the original pump , and no I don't remember sanding the cover , but I will . It may be a good idea to replace the cover if its available . As I just posted back to Bill on a previous boat a had wear on the back plate as well as the cover. On that pump it had a very thin plate in the back of the pump that could be replaced , a wear plate. I don't know if this pump is the same. It fit so precisely it appeared to be the pump housing itself. Thanks for the suggestion.
Sometimes the pump housing becomes out of round.
Did you try changing the entire pump?
Also did you sand the plate that closes the pump smooth?
Kimberlite Amel Super Maramu #376
Bill , The impeller looks good even though it is a couple of years old and a couple of hundred hours on it . I will replace it per your suggestion , that it can look good , yet not provide adequate flow volume.
Yes, check everything from the sea chest to the impeller on the engine.
Mark, I keep my heat exchanger clean , its never been clogged more than one or two passages . I think I need to work my way from the strainer thru the pump.
Thanks , Pat
Ditto on Bob’s comment. I would suggest starting at the sea-chest and working your way down the salt water flow. The tranny cooler is easy to service (do not over tighten when putting it back on or reconnecting the hoses). Also check the 90 degree elbows at the raw water pump. On the Yanmar, the raw water pump has a bar across it at the intake side. Not sue if Volvo has the same. I found a small clam lodged in there once. It took me forever to find it. I tore apart the entire cooling system and missed it the first time.
Most temperature issues are because the heat exchanger is not clean enough followed by after cooler flow issues for turbo charged engines. Taking the heat exchanger to a radiator shop is better than messing with the acid required aboard the boat.
Also check the thermostat on the coolant side. You can place it on a pan of water on the stove with a thermometer in it heat the water. Note the temperature when the thermostat operates. Check to see if it is in spec.
My guess is if you closely inspect the seawater flow passage from start to finish, you will find something partially blocked.
Also, check the manual for operating temperatures. Engines will increase in temperature as RPM or load increases. However, there is a cap on what it should warm to. The range should be in the owners manual. Our Yanmar runs at 180F under moderate load and 190F at full load.
Hope this helps. Good luck.
With best regards,
Sailing Vessel - Cream Puff - SM2K - #275
Currenlty cruising – Turks and Caicos Islands
Pat, the transmission oil cooler should be checked every service as yes it does get blocked, mine blocked first time after 300hours in southern Australia due to the type of spaghetti thin sea grass in Port Phillip bay and the symptoms were identical to what you describe, temp goes up with revs, less water out exhaust. Easy to spot with the engine room hatch open look at the hose coming out of the transmission cooler, rev to 2500 (out of gear if your in dock)🙄 and the hose between the seawater pump and the trasmission cooler flattens as the pump creates a vacuum in this pipe as it's sucking and not getting flow.
The local Volvo dealer cleans the oil cooler every service, but he says this is good because the smaller tubes in the transmission cooler catch the weed and protect the heat exchanger from blocking up. It's a a really big job to clean weed out of the heat exchanger.
Amel 55 #25