And does your HE have one closed end? Im fearful of pushing anything in the tubes for fear of packing in any clogs for good!
Universal M-12 running hot
- Thread starter odaydokay
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I used a wooden dowel. Less expensive than a 12" drill bit and I think less chance of damaging a tube. It worked well.
Mine is closed on the anode end. Just be gentle when putting the cleaning rod in the tubes. Do the acid soak first and rinse it out. I used diluted muriatic acid available at hardware or pool supply stores. .
Good input fellas. Note to AdamV: I do not have closed end HX; used to but now Mr. Cool open both ends and am grateful for that. At season's end, it needs a good cleaning. The drill idea is great. Wonder if coat hanger might also work (longer) also chased by a jet of water. Cutting the anode down is clever idea. You guys and your willingness to share info is what makes this forum great. Hats off to you all!
Quick question: When one pulls off both end caps, should any coolant come out or is the coolant portion sealed off completely (unless unwanted internal perforation of course)
Quick question: When one pulls off both end caps, should any coolant come out or is the coolant portion sealed off completely (unless unwanted internal perforation of course)
I prefer the 12" long drill bit which is long enough to go all the way through the tubes. You are trying to remove the solid deposits that did not come out with the acid bath, so they are hard. If you push something through it will just wedge the deposits tighter. the drill bit (by finger twisting only) will scrape the edge of the deposits away and bring them out a bit at a time.
I just cleaned my HX. I used a coat hanger with the handle bent 90 degrees so I could rotate it. My HX has two caps but the second one is behind the raw water pump and nearly impossible to access without removing the manifold also. After I unplugged the HX, I ran Barnacle Buster through it for several hours. The BB was still bubbling a bit when I shut the wash down. I know the HX has at least 12 years of service but I don't know when/if any of the previous owners flushed it out. The engine runs really cool now. But after this hurricane season, I'm flushing it again just to make sure it's clean.
I see your point. I will need to figure out what diameter bit I will need to buy, probably can only do by pulling the cap and taking a shorter bit to size and then going to the hardware store to get the right one. Probably needs to fit a tad snugly in those tubes to do the clean out properly.
you would hope not- the coolant is in a closed system and doesnt / shouldnt have contaminants such as raw water, debris or bits of zinc anode to contend with
As I said earlier, I have needed to unplug my HX twice in the last 24 years due to overheating. The first time was on a 10-day August cruise in the San Juan islands in WA which means little to no wind, so you motor everywhere. After a couple of days, my overheating was to the point where anything over 1400rpm's would put me over 200º. I pulled into Friday Harbor and found a shop that had some old wire coat hangers and did just what you describe with the HX still on the boat. It was effective enough to allow me to finish the cruise, but I was still having problems with overheating at higher rpm's, so I pulled it out and sent it to a radiator shop which cleaned and test it for $80. 10-years later, I was again starting to to overheat so I called the radiator shop, but they said the price was $150 min and would be more depending on what they found.
my acid and drill bit got it completely clean and solved the problem for about $20.
I am not sure if any coolant boiled out because I had added a coolant recovery tank so anything that was lost was pulled back in when the engine cooled. I did not get much above 200º because I was keeping a close eye on it and adjusting the rpms to keep it under control.
That makes sense. 200 is kind of where I draw the line also. I am just wondering if I could have burned off any coolant running at temp as I was down just a bit.
If you do not have a recovery tank, you will always be down a bit. The water expands when it is hot and contracts when it cools. If you fill it to the very top when cold all of that expansion will get forced out the first time the engine heats to running temperature. When it cools, it will be low. Water expands about 2.5% / 100º so going from 70ºto 200º on a 2-gallon system will cause 1 cup of fluid to be forced out of the system.
This is true. I do not have a recovery tank but my remote heat exchanger has a tall filler neck that permits expansion without fluid loss. As long as I do not fill it to the very top I never have to add any fluid.
The exchanger is at the end of the line.. Start with the thru hull. Remove the hose and briefly open. If you don't get a fountain, there is your first problem.. Be prepared to rod it out if there is anything less than a fountain.. Move on to the strainer.. If the screen is clogged, clear it.. Now test the strainer inlet as you did the thru hull.. Briefly open that thru hull with the strainer open.. Again, a fountain is what you want to see. Your next stop is the raw water impeller.. But since you weren't really cooking, I'd rather think the impeller was ok.. The exchanger is your last stop. It may need rodding out..
Discovering a blockage at the thur hull and clearing does NOT mean you've solved the problem until you run through the possible down stream gremlins..
Discovering a blockage at the thur hull and clearing does NOT mean you've solved the problem until you run through the possible down stream gremlins..
Good points and reminders. Thanks. I know the strainer (outboard "South Bay" cheese wedge style, no inboard strainer) needs another scraping and its holes probably need reaming as well. Impeller is good. HX needs a good ream and hose coming out of it probably also. I am a lot less nervous at 180 degrees than I was at 200, of course.
Am closing out this chapter. Ran a lot this weekend and did not see more than 175. Does not take many bits of 'dead" anode in the outlet end of the HX to cost one 20-25 degrees!