Man, that day did not go as planned.
It started off well enough. I picked up the fish—yay! Still alive. I can’t believe it.
This is how you transport a fish on a Mexican bus.
Then I got back to work on the engine. A while back I noticed that I seemed to be losing coolant. This could be from a head gasket leak, so I decided to try Bar’s Head Gasket Repair. Step one was to drain all the coolant in the system. I did that and flushed it a bunch of times. Then I disconnected the hot water heater hoses and just ran a new hose directly between the two engine fittings. Next it was time to add the Bar’s. This stuff is basically tiny flakes of metal and who knows what else. It’s supposed to run through the system and when it gets sucked through a crack I guess the metal piles up and seals it.
Following the directions I ran the engine for five minutes then added more water to top it off. Next I ran it at idle for fifteen minutes. About twelve minutes in the engine overheated. I did not see that coming. I shut the engine down and immediately drained the system again, getting all of that Bar’s stuff out. After draining everything I refilled the system with water and decided to run it again for a few minutes and see what happened before draining it once again.
The temp quickly climbed beyond normal and I shut it down again. Now I was getting worried that the Bar’s screwed something up.
At one point I managed to bust a wire off of the alternator. It broke off because it was so corroded. I consider it a small miracle that I was able to get it reconnected. A new high-output alternator was supposed to come down with me but didn’t quite make it in time. That will be a nice upgrade.
I didn’t have enough coolant to fill the system so I made a trip to the store, came back, and filled everything up yet again—this time with nothing but a good clean coolant mix. I fired up the engine and crossed my fingers. Five minutes, one-hundred-five degrees. Ten minutes, one-hundred five degrees, higher RPMs, one-hundred-fifteen degrees, five more minutes, one-hundred-fifteen degrees. Breathing a sigh of relief I left it running and went outside to work on securing the propane tanks. Half an hour later the engine was still humming along at one-fifteen.
So it appears to me that the problem was with running only water through the system. With the coolant back in I’m good to go again—though I probably didn’t fix any problems.
Because I had to wait for the engine to cool so often this little project ate up my whole day.
I need to get out of here. The weather looks good, though it does appear there will be liberal use of the engine as there is so little wind forecast. Not a hurricane in sight.
And though I try, I just can’t get inspired to take pictures here.
6 Comments on “Overheating”
Did you remove the thermostat before running the bars through the system? I’ve never had luck with using bars but other people claim to have had good results. If the head is leaking on the outside you should see coolant in the bilge if it’s leaking on the inside your oil would be milky. Needless to say coolant in the oil is very bad. Than again it might not even be a head gasket leak.
Pat, The coolant runs through the water heater, right? Possible that the coolant is leaking into the water heater through a hole in the heat exchanger? Of course, if the leak was substantial then it would be noticeable while running the hot water.
What Guymon said is true about water in the oil. It’s easy to see though because when you pull the dipstick a gummy, milk film will be at the top of the stick as the hot oil tries to evaporate the water.
Hi Pat – We have followed your blog for a number of years. Right from the VW days. We also travel through Mexico in our VW Westfalia. I totally agree with you about San Carlos. Although we stayed in the Totonaka RV Park for a few nights and it is nice, there is just something about that town that I did not like. I couldn’t put my finger on it either…Safe travels!!
Do a quick web search on oil and coolant analysis. Your big name auto parts stores might even have prepaid sample containers to mail off. After everything is running right you can pull a sample and send it for testing. Pretty interesting. Normally the oil analysis is done when you change your oil and it tells you if you are changing on time. They give you the viscosity and contaminations. Usually comes with a cheat sheet and pointers if anything looks off. If you do them regularly like every oil change or annually they can actually warn you of impending failures such as coolant in the oil and certain metals that point to failures like piston rings et… Ive never done one on an inboard but have on semi trucks and passenger vehicles and they are normally worth the small cost in peace of mind.
Well curiosity got me and I spent three hours finding out what kind of engine you had (a built in light down there would help) and even found a a test result on the same motor on one of your favorite forums. http://www.sailnet.com/forums/diesel-engine-forum/83416-ford-lehman-oil-analysis-**help.html and they mention that they got guidance on the test numbers so it is doable.
First of all you are now up for a new Volvo-Penta engine, but maybe not so fast. Water is a much better coolant than anti-freeze/Prestone stuff because it dissipates the heat much more efficiently. I never use Prestone in any of my collector cars, ever. Next, you said that the engine temp is running between 105-115 degrees. Much too cool, which indicates the thermostat is not working anymore. It is either open too much or closed too much. Engine should run at 160-185 degrees. If it doesn’t run at the right temp, then the system will discharge the coolant somewhere and after running for awhile it begins to heat up. If you don’t have a crack in the engine,then a new thermostat will do it. NEVER us Bars’ Leak as it is CRAP and always screws something up. MaxF.
The boiling point is too low and the vapor pressure of pure water is too high to for your eninge to run at the right temp. It must be mixed with coolant. The other commenters are right when they say 115 degrees is too low for a running temp. You will get nasty carbon build up at this temp unless maybe it doesn’t run hotter when you are actually pushing the boat. Sounds like your thermostat is stuck open. The bar’s can cause this.