Re: [Amel Yacht Owners] Raw water cooling

Patrick McAneny

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.
Pat SM#123

-----Original Message-----
From: 'Bill & Judy Rouse' yahoogroups@... [amelyachtowners]
To: amelyachtowners
Sent: Fri, Mar 31, 2017 5:46 pm
Subject: Re: [Amel Yacht Owners] Raw water cooling


On Fri, Mar 31, 2017 at 3:57 PM, Patrick Mcaneny sailw32@... [amelyachtowners] <amelyachtowners@...> wrote:
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

-----Original Message-----
From: 'Mark Erdos' mcerdos@... [amelyachtowners] <>
To: amelyachtowners <>
Sent: Fri, Mar 31, 2017 9:43 am
Subject: RE: [Amel Yacht Owners] Raw water cooling

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
From: []
Sent: Friday, March 31, 2017 4:49 AM
Subject: Re: [Amel Yacht Owners] Raw water cooling
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.
Bob Grey
Renaissance 3
On Friday, March 31, 2017, 08:38, sailw32@... [amelyachtowners] <> wrote:
I always check my exhaust for water flow after starting the engine , a Volvo TMD 22A. It is difficult to determine as the exhaust pipe is partially under water , I wish it had been installed a couple of inches higher. I have never thought I had as much water expelled as I would expect. I have seen many boats which seemed to have a more robust exhaust of water. My temperature seems to rise when the rpms go above 2500 . The heat exchanger is always kept clean . I have never taken off the raw water manifold or the transmission cooler, for those that have , have you found any blockage (growth etc.)that could inhibit the flow of water .
Pat SM#123

Join to automatically receive all group messages.