I have an question, (oh no, new guy again).... Sitting idle, my Univ. 5444 barely gets up to operating temperature, in fact, usually less than 180 degrees before I have to leave and shut her down. I have taken the boat out now 4 times. First trip it was run hard by a friend "testing everything" at over 2K RMP and it ran hot. Two trips later, running out at 1500 RMP, it stayed in a normal temp range. Two trips, no issues. While attending to the main cover, my other "friend" ran it up to 2K RMP and she ran upwards of 210 degrees. So, need some thoughts or conclusions or confirmations.
1. Water impellar changed last year, export volume of water seems normal, but admittedly looks less when the block is running over temp of 200 degrees.
2. Could it be calcium build up in the heat exchanger?
3. Did he, we , hurt the engine, short run, maybe 15 to 20 minute, let engine cool before shutting down.
What do I look for first?
Verne
Verne,
My 5444 in an '82 367 also ran hot when I first got it.
It ran fine up to about 1800 rpm. Higher than that , it got hot quick. could not push to > 2500; otherwise it went up over 210.
I did the following:
1. flush out the heat exchanger (raw water side and coolant side), dip in bucket of diluted muriatic acid, then dip in baking soda solution to neutralize the acid, then wash out with water. Eyeball down each cooling tube to make sure they are clear. Mine had crud.
Step 1 cleared the over heating issue.
In addition
2. Remove the top of the V drive. If yours is like mine, your raw water passes through the v drive before getting to the engine. That upper water chamber was 80% full of hydrogen sulfide-smelling crap.
3. Change impeller, maybe it's bad.
4. Hose from exhanust manfiold to Hx went in a loop, creating a high spot (air bubble!). I removed that and put in a short hose that goes slightly down hill from exhaust manifold to Hx.
5. Change or check all hoses to make sure there is no blockage
6. Make sure you belt is tight. If it is loose, it will not run the fresh water pump.
7. you might have an air bubble in the coolant side of the system, intermittently blocking coolant flow.
Mine also had a 160 degree thermostat (ran cool at idle), change it to a 190 degree thermostat.
About a year or so after no over heating, the prop a thick layer of barnacles grew on the prop, which made the engine overheat again and could not get the engine to get up over about 2300 rpm with max throttle. Make sure the prop is clean.
Attached is a manual for these engines.
Superb support and help to a newbee. Thanks ! You are correct, I would have never even considered looking at the V Drive. I think this is mechanic time to be 100% sure this is done correctly and not introduce other issues from my semi - I want and can do this, I think - novice mechanic abilities. I work, hard,,, and do not have but limited time and access down to my boat. So I have to make every hour on her count. May I ask two more questions without fear of being a nuisance?
1. What should the typical operational temperature be? (down south in Mobile AL) I thought I read about 180 degrees. If you put in a 190 degree thermostat is that not a guarantee of running hotter than suggested temperatures? Do you think we ran too hot at 210 degrees for a few minutes (5 or 10) before I noticed?
2. What is the normal safe operating RPM for my engine with a folding prop? Can I run safely at 2,000 or even up to 2500 RPM at that age?
Thanks again, I admire and respect you guys already.
Verne
Manual states operation temp is 179 to 190 degrees.
I've gone over 210 two times (once on initial delivery and once when belt broke) and engine is still ok.
the block and head are cast iron; there is no aluminum in the part of the engine that gets hot
Only aluminum parts are the rocker cover (valve cover) , gear case, and thermostat housing, none of which get hot.
I can't help you with question #2; I don't know. Only thing I have to go by is the manual: 3100 max rpm.
my boat with 2 blade fixed pushes at hull speed at about 2600 or 2800 rpm ( I think, some where around there, I don't remember).
Here is the prop/ speed info I didn't know earlier.
http://www.pearson365.com/forum/index.php?topic=1352.0
I had a similar problem with the Westerbeke W40 in Sea Dragon (1981 W40 in an 81 Cutter). In the summer I could push the "temp" needle too far to right if I motored at RPM's greater than 2,200. In speaking with the Westerbeke rep at the Annapolis Sailboat show I learned that this is common problem on several models of their Diesels in which there is a Raritan hot water heater as part of the cooling circuit. The hot water heater restricts water flow, due to the smaller passages, resulting in overheating under certain conditions. The answer for me was to install a by-pass in the cooling circuit to increase flow. See the link below for details.
http://www.sailingseadragon.com/Engine%20Cooling%20Mod.htm
This solved two (2) issues I had, 1) engine overheating & 2) very, very hot water on board.
This may or may not help.
Garner
Garner,
You reminded me of a similar change for Universal engines, thanks.
Verne, Although these links refer to a Universal 5432, it applies directly to our 5444 engines as well.
Mine was already plumbed like this when I bought it. You do not have to replace the barbs on the engine; they probably won't come out easily anyway. You will likely need plastic reducer couplings to go from the 1/2" on the engine to the 5/8 or 3/4" barbs on your water heater.
http://sankaty.homestead.com/waterheatercircuituniversal5432.html
http://sankaty.homestead.com/water_heater_hook_ups.html
http://downeasteryachts.com/archives/2029
http://www.pearson365.com/forum/index.php?topic=31.0
We looked at a Pearson 365 before we bought Polaris. It's problem was a plugged inlet with sea growth plus bottom paint. Cleared that, then it worked fine. A plug or restriction can occur at many places in the system though. On Polaris, cooling water comes in through a screen, through a strainer, through the Vee drive heat exchanger, through the transmission heat exchanger (we have a velvet drive), to the raw water pump, through the engine oil heat exchanger, through the coolant exchanger then dump into the exhaust. It changes diameter from 3/4 hose to 1/2 them back to 3/4. This is what it looked like before cleaning. This boat lived in Southern California.
An IR thermometer helps in diagnosis. You can use it to see if your thermostat is opening when it should. You can also see what is getting hot. If the heat exchanger isn't getting hot, it isn't working. You can point it at the hoses and see how hot they are. Is your domestic hot water hot after running? If so, you are getting coolant flow. It's also possible that a past failed rubber impeller could block the passages downstream.
On the engine coolant heat exchanger, you can remove the end caps, at least if it looks like ours to see what is going on. Checking the raw water strainer is easy and could solve the issue. That is what is supposed to catch stuff that might get sucked in. Kelp, jellyfish, and other sea life can get in there.
Hey Guys,
I have tons of experience with my 5444 overheating. I have owned my P36 cutter/ 367 for almost 13 years. The first several years of ownership I battled an overheating engine and went through the entire cooling system. After much research, this is the final fix.
The Universal 5444 came with an Oberdorfer pump that was undersized and will never be able to pump the proper amount of water through the cooling system. The Univeral M50 (same as the 5444) comes with a newer pump. I believe the part number for the new pump is Oberdorfter #N202M-15, and is about double the GPH of the stock pump. http://www.oberdorferpumps.com/pumps/rubber-impeller-pumps/n202m/ (http://www.oberdorferpumps.com/pumps/rubber-impeller-pumps/n202m/)
The new pump is an exact replacement for the old stock pump. My engine has been running at 185 degrees for the past 10 years with the new pump. Double the amount of raw water in the exhaust. Happy engine.