XP25 Overheating

I have a 1985 Ericson 32 with a Universal xp25 engine. I have been updating the boat over the last two years of ownership including the 12 volt system (agm batteries, Balmar charging system and charger / inverter,) new electronics (Raymaring C80 radar / chartplotter), standing and running rigging, sails (new summer jib for the wild SF bay and cruising spinnaker) plus many, many other upgrades. I am so pleased with the design, construction, and sailing performance of this boat. The previous owner did many cosmetic upgrades including new interior, dodger, and anything pretty. Overall the boat is in unbelievable condition for a gal of her age. But....

I have been plagued with an overheating condition. When I first bought the boat I had a real handy neighbor help with upgrading the mechanical systems. We installed a fresh water filter on the cooling intake, installed a Racor fuel filtering system, and of course changed all of the fluids. I recently sent a sample of the oil (6 months old) to Blackstone for testing. The results came back with great results it every area with the final coment, "Great engine condition." Initially the boat would overheat if I ran it full throttle (2700 rpm) for more than 10 minutes. Since I rarely needed to max the throttle (it is a sailboat afterall) this was a minor concern. However, lately (this weekend specifically) the boat is exceeding 180 degrees after running at cruising rpm (2ooo rpm.) after 40 minutes. The water intake filter is clean, I just changed the oil and coolant, the water pump impeller is new, and it still heats up at cruising speed.

I am thankful that the Blackstone Oil Analsys came back with smiley faces but I am at a loss as to what to do next. I am not a diesel mechanic but do like to do all of my own work. Should I throw down the glove and hire a mechanic or do any of you have suggestions as to where to go from here. I thought maybe the head exchanger needs to be boiled out but that is just a guess.

Please lend me some expertise in this very difficult area.

Open up the heat exchanger. I'll bet dollars to donuts that the seawater passage tubes are blocked by build-up, crap or old impeller bits or something.

Also check each hose in the raw water circuit to make sure there isn't an impeller bit jammed in there either.

I concur with Nate.
Next, I would replace the thrmostat if its age or condition is uncertain. Then I would re-hose the engine closed-cooling system, if this was not done recently. Look for any swelling around the clamps.

Remember that, while the percentage chance is low, it is possible for an old hose to have a separation internally that will create a "bubble" inside and restrict flow.

Dimes to donuts, the heat exchanger fix will get you cool again.
Anyone know when the stock heat exchanger diameter on that series of engine was enlarged? My '88 has the larger version, FWIW.

Loren

Sounds like it is slowly getting worse, so my guess would be as the above, check the heat exchanger, and then also the exhaust manifold where the raw water is dumped into the exhaust riser. You folks down south have a higher salinity level so these things happen more often than up north. also make sure something isn't stuck or living in your raw water intake. good luck, Harold

Loren Beach said:

Dimes to donuts

Click to expand...

Wow. I need to find where you shop for donuts. With my donut-habit I could save a lot of money at your prices.

Oil analysis

The guys have steered you in the right direction for the overheating problem, and between the thermostat (my guess) or the heat exchanger I bet you will solve this one pretty soon.

On the subject of oil analysis, a single test tells you absolutely nothing. These things are not capable of a snapshot view which has any real meaning. The way to use this process is to take about 3 samples, say every 10-20 hours of use. This will (hopefully) establish a baseline condition in terms of metal and mineral content in your engine, or in the worst case, indicate that you are making more metal each time you test (bad). Assuming nothing changes much over the first few tests and you now have the baseline, sucessive tests will then show any changes-increasing metal from baseline is not a good thing-

The quality testing services take into account things like hours since oil change, etc, and most importantly, there should be an explanation of what I just described so you know how to use this data in a meaningful way.

Best of luck!

S

David, not that it's relevant to your question, but are you sure you have a Universal 25XP, which is two horsepower more than the M25 in my boat and which is the same year as yours?

Another SF Bay E32...

David,

well, not under any pretense of being an expert, I'd first check the intake seacock. Simply stick a long screwdriver there. A relatively small piece of debree that may be stuck sitting there may be just growing over with some algae making your life harder and harder.

If it does not help - well, you've just lost 10 minutes and let some of the bay to come in... Go for the next element in the chain (The Exchanger), as Nate, Loren and all others suggested. If it does - heck, you've just saved yourself a bunch of time and money...

Regards,
Stan

If you want to check the water flow, do what my yard told me to do, namely start the engine and pull the exit hose off the heat exchanger. The water should be coming out like a fire hose. If it is not, then repeat the process going back up the line.

I'm sure I've put this on another thread, but we have an A-4 with an overheating problem, which only occurs when we're on port tack with a heeling angle of 5 degrees or more.

We've replaced all the hoses (no heat exchanger), replaced the thermostat, acid flushed the engine, cleaned out all the filters, strainers, etc. We can stop the engine, let it sit for 30 seconds and the temp comes right back down. Doesn't happen on starboard tack or on flat water. We're convinced it is simply haunted but haven't had the time to hire an exorcist.

Jim McCone
Voice Of Reason E-32-2 Hull #134

I have an '86 model Ericson with a Universal M-25. I experienced similar over-heating problems and found no evidence of a clogged heat exchanger. I use a strainer on the raw water intake. When researching alternatives, I discovered that Torresen Marine advertised a manufacturer's upgrade from a 2" to a 3" heat exchanger. I upgraded and the problem went away.

Thanks for all of the great help

I spent some time this weekend working on the overheating problem. I first checked the water intake through hull and found it to be clear. Next I checked all of the hoses and found them to be in "like new" shape. Next I replaced the Thermostat and still the problem persisted. I bled all of the air out of the system because I have heard that this motor hates air anywhere in the system. I did not blead the air out of the water heater as someone had sugested but I plan to do it next weekend. The last thing I will do is remove the heat exchanger and clean it with "pool" acid and maybe even replace the 2" exchanger with a 3" unit. Torrensen Marine mentions that this should be a good upgrade but at 5 clams, I hope that I can avoid it.

Thanks to all for the great help and suggestions.

david, do a search on here for heat exchangers. Someone mentioned a company that made replacements for about $370 i think.

Someone on ebay selling them for less. Seakamp engineering i think was the name.

http://cgi.ebay.com/ebaymotors/ws/e...d=1,1&item=4600008349&sspagename=STRK:MEWA:IT

It could also be something in the riser, that happened to me once. There is a hose that is attached to an elbow at the top of the riser, Simply unscrew the elbow and with a screw driver or something simular rattle it around in the riser. If you encouter black goop that is the problem. Start the engine and you should get a lot of black goop out the exhust. Running a screw driver around inside the riser is usually enought to fix the problem, but if not pull the riser and clean it out. If you have pulled the heat exchanger and there is no pieces of impeller in it and the exchanger is clean, the raw water pump is working correctly and the side plate is not worn, then the riser is about all that is left.

Have fun

You might also take off the output hose on the waterpumps (both but one at a time) and run the engine briefly, while putting your finger over the outlet and make sure there is actually pressure. I once had plenty of water discharge but the moment I put my finger over the outlet, the pump stopped pumping. Had volume but no pressure.