Originally Posted by Jiminri
OK, obviously I'm doing something dumb because I cannot get my diesel to suck up the anti-freeze.
Last year the PO walked me through the process of winterizing the engine.
1. Close seacock.
2. Remove screw-in plug from fitting in raw water supply hose between seacock and strainer.
3. Attach short hose to fitting described above and put other end of hose in jug of anti-freeze
4. Start engine--pump then sucks up anti-freeze. Continue until water from exhaust is pink.
Last year...piece of cake. This year? Suck up some anti-freeze, then stops...looks like air in line.
Yet, with seacock open and plug in fitting (normal mode), the engine runs fine and spashes come out exhaust.
So, how can it NOT be picking up the anti-freeze??
As I said, I must be missing something incredibly obvious. Any ideas?
#1 Have a bad impeller missing a vane or two..
#2 Have an air leak in your intake set up..
#3 Have a worn pump body that does not prime well. (This could also be mixed with #1)
Accelerating the motor can sometimes help to overcome the air lock..
I have seen numerous HX's, water heaters, fittings, Sea Frost heat exchangers, etc. cracked and frozen when folks suck in too little AF..
I just did a Ford Lehman 6 cylinder on a Grand Banks two weeks ago that took 16 gallons confirmed with actual concentration measurements using a sight refractometer.
What folks often fail to recognize is that the antifreeze IN to water OUT ratio is NOT a 1:1 displacement ratio....!!!!
The new AF mixes with the existing water already in the RW system and it takes far more AF than the volume of the system to get to adequate freeze protection.
Here in Maine I want to be burst protected for about -40F (it's been a while since that happened but we do see -10F to -20F)... PG AF should not be diluted any more than it already is by the manufacturer. Thin walled copper tube heat exchangers are quite fragile and it takes very little frozen water to cause a failure.
I have a Universal M-25 HX kicking around that froze and split caused by the owner only sucking in two gallons.
Either get a sight refractometer, to test what is coming out of the exhaust, or suck in more AF than you think you need. Merely "seeing pink" can result in a split HX.... Most small aux engines take four or more gallons to be adequately protected.. If the boat has Sea Frost engine driven refrigeration this can push the AF to 5-8 gallons.
Draining off some RW first can cut down on the amount of AF needed but your time is probably work more than the additional $12.00 in AF...
Every winter we have winterizing ooopses that could have been avoided by a few more dollars in AF...