Silt in cooling system

[Dickv]

Had the mis-fortune of becoming grounded (tide went out), and ended up powering out of the grounding. On the way back to the marina temp guage rose to 220 degrees and stayed there. The 350 has a fresh water cooling system, and there was no damage to the engine, but I evidently sucked up large amounts of muck and silt.

The dealer replaced the prop and impeller, and flushed the engine, but I am still now running 218 degrees, so suspect there is more silt/muck to flush out.

Any ideas how or where to attack this, or where to flush from? What to flush with? The fresh water system is full of anti-freeze, so I don't think there is an issue there.

Any help or advice greatly appreciated.

Thanks,

DickV

[tmdog]

Noting the repairs that have been done, two other things can be done to relieve the cooling problem. Flush the oil cooler and the heat exchanger, these are possible suspects.

[BigGrizzly]

what boat and outdrive do you have. A alpha has an internal waterpump in the outdrive and couls be broken. A bravo does not have aninternal pump. Except for TMdog's suggestions i would check the guage and replace the sending unit. Put a sea stranier on that unit unless you already have one and it should, all my boats do.

[Douglas Dorsi]

I just purchased a used Aronow with sealed fresh water/coolant system. It had a temp problem and after having replaced sea water pump impeller and temp sensors it still had a problem. They found that the last owner evidently sucked up a lot of sand that settled in the heat exchanger. After cleaning it out the problem was solved. If you have this configuration I would remove the heat exchanger and have it cleaned out at a radiater shop. That cured my problem. Good luck and let us know what resolves your issue.

[Donzigo]

You can chase a problem like this one for a long time, or you can start by tracing the water supply form the pickup on the outdrive and go from there. I had a problem like this one and from the same grounding/sand issues. I found that a shell had lodged in the outdrive housing where the line goes into the boat. You've got to go the whole way and not look for a quick fix.

Bottom line, I changed the pickup from an outdrive based pickup to a brass thru-hull pick up, that provides about three times the water supply and goes straight to the strainer (Gill). There have been no other water supply issues since this change. The pick up being just below the strainerin the engine room floor, prevents any debris from getting into the system, since it will always be much higher than the outdrive. I have always wondered why boat builders don't use a thru hull pickup, since it is so much more efficient and eliminates so many problems with water supply.

[Douglas Dorsi]

You can chase a problem like this one for a long time, or you can start by tracing the water supply form the pickup on the outdrive and go from there. I had a problem like this one and from the same grounding/sand issues. I found that a shell had lodged in the outdrive housing where the line goes into the boat. You've got to go the whole way and not look for a quick fix.
Bottom line, I changed the pickup from an outdrive based pickup to a brass thru-hull pick up, that provides about three times the water supply and goes straight to the strainer (Gill). There have been no other water supply issues since this change. The pick up being just below the strainerin the engine room floor, prevents any debris from getting into the system, since it will always be much higher than the outdrive. I have always wondered why boat builders don't use a thru hull pickup, since it is so much more efficient and eliminates so many problems with water supply.

The pickup makes a lot of sense but I always thought (maybe wrongfully so) that one of the reasons you would want to pick up through the out drive is to maintain flow when the boat is catching some air. It is not my goal to be running in that mode to any extent but is this a negative aspect of the through hull arrangement from your perspective? Per your other point if you do not chase down all the passages insuring they are clear you may never know what you really have. What does it take to check the outdrive for cleanliness? Removal? I understand the passaage is possible a hose in the drive and can get kinked from drive stored up for long periods plus get plugged as you mentioned.

[Douglas Dorsi]

Had the mis-fortune of becoming grounded (tide went out), and ended up powering out of the grounding. On the way back to the marina temp guage rose to 220 degrees and stayed there. The 350 has a fresh water cooling system, and there was no damage to the engine, but I evidently sucked up large amounts of muck and silt.
The dealer replaced the prop and impeller, and flushed the engine, but I am still now running 218 degrees, so suspect there is more silt/muck to flush out.
Any ideas how or where to attack this, or where to flush from? What to flush with? The fresh water system is full of anti-freeze, so I don't think there is an issue there.
Any help or advice greatly appreciated.
Thanks,
DickV


Did you find your problem. Maybe we can learn something from your experience.

Doug