Coolant Resevoir Keeps Filling Up.

Re: Found the Problem.

Good day, My dockmate had precisely the same problem recently and the problem in his case was a pressure cap which had the rubber sealant portion dried and therefore allowing coolant to discharge into the overflow container. The caps are rarely inspected for any reason, however a most important portion of the cooling system paricularly in cases where the operating temperaures have been elevated significantly. As you probably know 1 p.s.i. of system pressure increases the coolant boiling point typically by three degrees. By the way, a compression test will not reveal a blown head gasket ordinarily as you are measuring combustion presssures which are indicative of the condition of piston ring sealing and valve to cylinder head seat condition.
 
techmitch said:
I know I'm Jumping in a little late here, but the above statement is impossible.
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You have done enough testing it's time to pull it apart techmitch is right a leak down test will show you could have a blown head gasket if the tech did see bubbling in the coolant it might be a blown head gasket or a crack in an area where coolant runs.
 
Bob & Sue said:
You have done enough testing it's time to pull it apart techmitch is right a leak down test will show you could have a blown head gasket if the tech did see bubbling in the coolant it might be a blown head gasket or a crack in an area where coolant runs.
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Thank's Bob, at this point I would expect a more comprehensive report on the results of the leak down test. Although disassembly is eminent, it is highly important to find the root cause.
 
techmitch said:
I know I'm Jumping in a little late here, but the above statement is impossible.
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The word "concludes" is a little too sure I admit. The leakdown test concludes their are gases excaping into the coolant. It could of course be a cracked block. The leak down did conclude the boat needs to be taken apart at which point I HOPE it is only A head gasket!
 
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bigpursuit said:
The word "concludes" is a little too sure I admit. The leakdown test concludes their are gases excaping into the coolant. It could of course be a cracked block. The leak down did conclude the boat needs to be taken apart at which point I HOPE it is only A head gasket!
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The chances are much higher that it is a blown gasket...blocks don't usually crack unless they are full of water and exposed to freezing temps for a prolonged period of time....but a cracked block is a possibility, just a small one IMHO...
 
CliffA said:
The chances are much higher that it is a blown gasket...blocks don't usually crack unless they are full of water and exposed to freezing temps for a prolonged period of time....but a cracked block is a possibility, just a small one IMHO...
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It's got me freaked out even if it's a head gasket. The boat is 10 years old and only has 400 hours on the engines. Should
I do anything with the other engine as well?
 
rcknecht said:
Did you drain the fluid recently? If so, could there be air trapped in the coolant loop? Air expands when heated, fluids don't....
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Fluids DO expand when heated. What you may be thinking about is compressibility. Water/liquids are considered incompressible yes, however they will expand when heated. Not nearly as much as a gas but it will expand. As it warms, water or liquids in general, will lose density but gain volume just as a gas does. Water is at its most dense at 4C then it begins to expand above that temp. Aircraft have fuel totalizers that do account for this with fuel. Temps on jet fuel fall considerably on a long flight. The fuel volume decreases in the tank (even if excluding fuel burn) as the fuel cools however, the fuel density increases. Technically this means you could fill a tank with a little more fuel in very cold conditions by having colder fuel with more density. Were it not for overflow reservoirs in wing tanks, you could have enough expansion to start pouring fuel on the ramp if you filled up on a freezing morning but the temps increased enough by noon.

This would not explain why the reservoir would be filling up and staying full AFTER cool down even with a blown gasket. You may have an issue where the fluid is unable to be pulled back into the heat exchanger while it is cooling down for some reason. That would mean the heat exchanger would have some missing fluid after it cooled off. If you take of f the heat exchanger cap (after fulling cooling down) and it isnt full to the top but the reservoir has alot of coolant in it, that may be your issue, especially if it passed a pressure test. I cant remember if it did, I think you mentioned it passed some tests and looked like a gasket on another test but whatever. If it passed a pressure test, I would bet this is the problem. The fluid is allowed to expand and leave the exchanger but it is not being drawn back into the exchanger for some reason, maybe the exchanger cap has a problem.
 
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bigpursuit said:
It's got me freaked out even if it's a head gasket. The boat is 10 years old and only has 400 hours on the engines. Should
I do anything with the other engine as well?
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are you experiencing any problems with the other engine?...if not i would not go looking for trouble....

if you are still a little paranoid of the possibility of a bad head gasket in the other engine you can check for some of these symptoms:

check the condition of the spark plugs...if the tip of a plug is much cleaner than the rest of the plugs there is a good chance the head gasket is bad and allowing coolant to get into the combustion chamber...the coolant will be vaporized and 'steam clean' the plug tip...you may notice an erratic idle or engine mis-fires from that engine since coolant does not burn, but if the amount of coolant is low enough the idle and performance of the engine may not be affected at all....if a spark plug has coolant on it when it is removed you have a problem...if you see white smoke coming from the exhaust the coolant is being vaporized in the combustion chamber and the exhaust may have a 'sweet' smell to it....there are only two ways to loose coolant from a closed cooling system...it can either be leaked out or it can be vaporized in the combustion chamber...if you are frequently having to add coolant to the system you need to be looking for where it is going...as you have seen, bubbles in the coolant or radiator while the engine is running are also common signs of a blown head gasket...head gaskets can blow in different ways...one is when the passage between the coolant passages and the combustion chamber is opened up...this results in the symptoms you are seeing, bubbling in the coolant resevoir or radiator and the resevoir filling with coolant...a blown head gasket can also open up the passage between the oil passeges and the coolant passages...this will cause the oil to become cloudy or milky colored due to the mixing of oil with coolant...this is not good because coolant will quickly destroy bearings which could lead to a major engine rebuild...a blown head gasket may allow combustion gases and pressure to escape out into the engine bay which sometimes causes a whistling/wheezing sound from the engine while running...

but like i said before, don't go looking for trouble...you can almost always find something that is not 'perfect' and start throwing time and money at it when in the end it may not be needed at all...
 
CliffA said:
are you experiencing any problems with the other engine?...if not i would not go looking for trouble....

if you are still a little paranoid of the possibility of a bad head gasket in the other engine you can check for some of these symptoms:

check the condition of the spark plugs...if the tip of a plug is much cleaner than the rest of the plugs there is a good chance the head gasket is bad and allowing coolant to get into the combustion chamber...the coolant will be vaporized and 'steam clean' the plug tip...you may notice an erratic idle or engine mis-fires from that engine since coolant does not burn, but if the amount of coolant is low enough the idle and performance of the engine may not be affected at all....if a spark plug has coolant on it when it is removed you have a problem...if you see white smoke coming from the exhaust the coolant is being vaporized in the combustion chamber and the exhaust may have a 'sweet' smell to it....there are only two ways to loose coolant from a closed cooling system...it can either be leaked out or it can be vaporized in the combustion chamber...if you are frequently having to add coolant to the system you need to be looking for where it is going...as you have seen, bubbles in the coolant or radiator while the engine is running are also common signs of a blown head gasket...head gaskets can blow in different ways...one is when the passage between the coolant passages and the combustion chamber is opened up...this results in the symptoms you are seeing, bubbling in the coolant resevoir or radiator and the resevoir filling with coolant...a blown head gasket can also open up the passage between the oil passeges and the coolant passages...this will cause the oil to become cloudy or milky colored due to the mixing of oil with coolant...this is not good because coolant will quickly destroy bearings which could lead to a major engine rebuild...a blown head gasket may allow combustion gases and pressure to escape out into the engine bay which sometimes causes a whistling/wheezing sound from the engine while running...

but like i said before, don't go looking for trouble...you can almost always find something that is not 'perfect' and start throwing time and money at it when in the end it may not be needed at all...
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The other engine runs fine and has no symptoms. I just didn't know if it made since to always treat the 2 engines the same.
Is there any advantage to since someone is working on the boat this winter to just do both at once?
 
you are better off not treating the 2nd engine the same. that way if the mechanic does something wrong, he doesnt do it to both engines. on twin engine commercial aircraft that fly extended over water flights, one mechanic is not even allowed to touch both engines. each engine is serviced or repaired by a separate individual(s). when I was at Gulfstream, we had a mechanic put some pneumatic plugs on both engines. the engines are made to bolt onto either side of the airplane so when installed, they need to close off the opposite side pneumatic holes that are available to supply cabin pressure/heating etc. This guy put the plugs on both engines wrong and one engine failed on takeoff out of Long Beach, CA. The other engine plugs almost blew off too which would have been double engine failure out of Long Beach! Nowhere to go there either, no rivers. After that Gulfstream said no more single mechanic working both engines ever. think that could apply to us almost as well considering the consequences of dual engine trouble where alot of us go boating. maybe not quite as life threatening but a major PIA at the very least.
 
So I had the head gaskets replaced over the winter and the boat went in last week. Everything ran fine at the dock but after a long run (4 hours) the coolant in the resevoir had over flowed again. It wasn't much but still overflowed. The boat never overheated, in fact the temperature @ the gauges all looked fine. Is this possibly air in the system or is it something else?
 
run it again and see. I wouldn't go off the first time out.
 
Sorry to hear you still can't completly trust the engine although you had someone make repairs. Please forgive me if I overlooked anything you said back in 2011 when this started. Finding what is wrong will be easier by finding what is not wrong,one thing at a time. So,a few things about from Oct 2001 up to this point.
#1 Have you went to auto parts store to buy test strips and use them to see if coolant has exhust gas in it?
Negativity= low possiability of head and/or gasket failure. Postive= high possiability off crack block,head or gasket
#2 Have you changed the cap with the proper type for your system,or at minium had the cap tested by a radiator shop? If I understand the system you have,it is a closed system with a coolant recovery reservoir. Thats what I'm baseing my comments on. Coolant recovery requires a cap that alows the heat exchanger to draw only from the reservoir and non at all from astmosphere as it cools off after a run. You must also be sure of no pin hole or leak in the hose from cap to reservoir alowing air to be sucked in during cool down. Air in a properly working system will cause level in reservoir to fall every time you make a run and cool down,not increase.
#3 Have you been closely monitoring coolant consintration to be certain it remains exactly the same? If consintration weakens that points to the exchanger having a leak alowing sea water to enter the closed system.
After the above is confirmed good to go,is bottom of reservoir more than 8 to 12 inches below cap? A small capacity system often has difficulty drawing coolant through a head preasure(uphill):grin:.
Try these easy inexpensive( with high probability of trouble) tests before getting in deeper and costly.
Hopfuly you or your mechanic have already checked these but I never read where you said so.
Good luck and come back for insite from others if you don't corner it.
 
Thanks 2texoma for the feedback. Couple things; I cannot find test strips to test combustion gases in coolant anywhere. Do you know the name of the manufacturer? Also the cap is on a fill riser on the engine itself, not on the heat exchanger. I imagine that doesn't matter but I just wanted to clarify.
Also after the the boat was first put in the water I ran it and noticed there was a slow drip from the cap. I went to an auto store and bought a new 7psi cap. To make sure the cap wasn't the issue I put the new cap on the good engine(starboard) and put the starboard engine cap on the port engine. The port engine is the one with the problem.
 
Appears improvments were made since I last needed to test while Nixon was in office.:grin:
I found this by Motorvac Technogliges on Ebay for $64 along with others. Rather than test strips,ask the parts store for "combustion leak tester". My bad. :smt021
[SIZE=+1]Combustion Leak Tester[/SIZE]
[SIZE=-1]Part #:560000[/SIZE]

You might ask your local auto mechanic about testing your coolant since you are unlikly to find use for the tool again. Ask if you can bring coolant to him rather than the boat.
 
I had another compression test done with the following results; 1-160,2-150,3-150,4-150,6-150,7-150,8-160,5-140. This doesn't look right to me, have I been ripped off?
 
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bigpursuit said:
I had another compression test done with the following results; 1-160,2-150,3-150,4-150,6-150,7-150,8-160,5-140. This doesn't look right to me, have I been ripped off?
Click to expand...

Sorry,
Did you recondition the heads while off?

Your problem sounds like a head gasket or cracked head.
 
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