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Coolant loss

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timmy66commander

Member
Hello,

I have been loosing coolant and am trying to pin down the area. I cannot see any leaks or smell it. While using a combustion leak tester to test head gasket (blue dye), the heat exchanger did burp and overflow which then contaminated the dye. Until the heat exchanger burp, the blue dye did not change colors to yellow which indicates CO2 in cooling side of engine. Do not see signs of coolant in engine oil. Engine runs great and is the better running engine except for the coolant loss.


1988 Crusader Model 270/5.7

Compression tested good (170lbs all w/in 5%).

Manifolds were replaced in 2009

Any ideas?


Timmy
 
Have you looked real carefully at the water pump ? There's a weep hole near the back of the pulley shaft housing and if the seal is leaking it will drip from the underside and be very hard to detect. Have you noticed any a/f in the bottom of the boat ? Might help to slip a white oil absorbent pad under the engine and c heck it after a couple of days. Let us know what happens .....Lee
 
Check your torque on the riser/elbow gaskets surrounding the block-off plate. Coolant loss out the exhaust happens a lot.
 
two more items:

hose clamps not being tight enough and leak internal to the HX (from closed to raw side).

usually the color change of the dye show CO, a combustion by-product. Don't understand why the coolant burping contaminated the dye. If you had the cap off, the "burp" is common right before the thermostat opens.

You can usually get a loaner pressure tester from most of the big box auto parts stores...I've found them to be the best tool for these situations.
 
I agree with Mark....If you can't find it visually then a pressure tester could be your best friend. BTW...just how much coolant do you think you're losing ?...Lee
 
some update/more info, please keep the ideas coming!!

1. no leak at engine water pump
2. added over 2 gallons of coolant over summer (1000nm total over season)
3. No coolant in bilge/cannot smell
4. when heat exchanger burped, coolant entered into combustion tester, which then ruined the test fluid


Will check elbow/riser/manifold bolt for proper torque this weekend.


Timmy
 
The proper level for coolant in the h/e is about 1 inch below the cap rim according to crusader.I f you constantly fill it the cap level thinking that it's low the next time you run the expansion will push it out, presuming you don't have a coolant recovery system connected to the h/e. overflow. It's possible to put 2 gallons of a/f into the h/e and not really have a leak,if you are overfilling it over the course of a summer. Just something I thought I'd throw out at you...Lee
 
2X on that.

Many pre-GenV packages didn't come with the overflow bottles. Added them is straight forward and gives a much quicker & easier method to verify the coolant level.
 
Hello,

I do not have recovery tanks on the motors. The left motor did not need any coolant over summer. The right motor in question (from maintenance log book).

1. added 1 Qt (Apr 11 before launching)
2. added 1 Qt (May 14, 2011)
3. added 1 Qt (May 29, 2011)
4. added 3 Qt (July 9, 2011)
5. added 1 Qt (Aug 11, 2011)

Swapped H. E. caps between LH/RH motors (July 9, 2011) and I do not think it made a difference


Timmy
 
OK Tim...the key is did you drive the boat between the dates that you had to top off the anti-freeze. A quart can be accounted for easily but not 3 qts. I'm afraid you're going to have to invest in a pressure tester to try and track this down, it can be something as simple as a small crack in a hose or fitting that doesn't leak until it gets pressure on it. Earlier you said you changed manifolds....did that include risers and elbows ? Is your exhaust water leaving any kind of film on the water ? Sorry if it sounds like I'm all over the place, but a leak like this can be in any of a hundred places inside or outside of the engine and I'm just going with whatever comes to mind. Does the temp. actually increase on the affected engine or do you just find it short when checking it's level ?......We have to narrow this down somehow, and find what system it's in......Lee
 
Hello,

1. The boat did not sit at dock, put 1000 nautical miles on it this season.
2. Elbows/risers changed 2008. I have a full closed fresh water system. In my model of engine (Crusader M270) I do not believe the coolant leaves the manifold for there is a block off plate that separates the riser/raw water from manifold/coolant.


Will put pressure tester on Heat Exchanger and test as soon as I acquire/borrow one.


Thx,

Timmy
 
Tim..I think you misunderstood me when I said did you drive the boat between taking a/f levels ? What I meant was...Did you top it off THEN USE the boat before the next reading. That way I could tell wether you were losing fluid while underway or just sitting still. My theory of you topping it TOO full went out the window when you said you lost 3 quarts, it can only be 2 places...in the bilge or out the exhaust...as Jeff just said in the last post...there aren't any other options. What kind of different driving did you do before you had to add the 3 quarts ? There had to be something different to go from 1 qt. to 3 then back to 1 again, think about it. The only way we're ever gonna be able to help you is if when you read the posts and you see a question, make sure you answer that question in your next post or we'll never be able to eliminate anything. As Rick has said in previous posts "We're looking at your problem thru YOUR eyes" so if you don't answer a question in our minds we still can't eliminate it, and help you to move on.
Your a/f runs thru your block ,thru the water pump,thru the oil cooler. thru the manifolds and thru the heat exchanger, it's blocked from your riser and elbow, then recirculated thru the system all over again. The salt water is just used to cool the a/f in the heat exchanger and is dumped into the risers mixed with exhaust and out the elbow and exhaust system at the rear of the boat. As you can see , there are plenty of places to lose a quart of a/f along it's trip thru the engine and cooling system. That's the purpose of the questions, to try to ELIMINATE various possibilities until you're only left with the one thing that could be the problem. Please don't take this as being sarcastic, we don't know how much you know or can do , your words are the only way to find out, so if some of the questions seem simplistic, please forgive,but there's no other way for us to help you. Now in an earlier post I asked if the engine was actually overheating or did you just notice the a/f shortage when you checked it ? Also did you look at your exhaust flow and see if there's any type of sheen on the water ? At 1qt. short you may not have even noticed a temp. rise but at 3 quarts things should have definitely begun to get warm. Think of how you drove the boat differently in June to try to account for the extra 2 quarts of a/f that you lost. Above you gave us 5 readings, if you are overtopping the heat exchanger then 4 of the results could be from overtopping, only the 3 qt. reading would have been and actual problem, but you failed to tell us how you knew you were low,actually overheating or just looking before you would leave the dock for a trip with the boat?....Thanks Tim....give these guys enough information and they will solve your problem......Lee
 
usually, its the raw water that removes heat from the oil coolers, and that occurs before the visit to the HX and the exit routing thru the elbows.

another item - and the pressure tester can help find this one, too - the cap flanges are relatively easy to damage and, if that occurs, can prevent the cap from sealing correctly. In other words, give them a good inspection, especially when using the tester and a leak is indicated but can't be found.
 
1. Coolant loss happened while running vice sitting. I do not remember mileage/usage between adding coolant.

2. Coolant is added to BOTH left/right engines the same way, and only right engine continues to require more coolant.

3. 1988 Crusaders M270 5.7L do not have engine oil cooler, oil cooler is only for transmission. Less parts to worry about.


4. 1988 Crusaders M270 5.7L have stainless blank off plate between manifold and riser. No coolant in riser/elbow
a. This item is shown as #15, http://www.marineengine.com/parts/sierra_marine/catalog.html?[url]http://www.marineengine.com/parts/sierra_marine/crusader.html[/URL]

5. There is a sheen on water at low rpm’s but it is the same on BOTH motors and do believe it is unburned fuel from old/leaky Carb’s.


I will procure a pressure tester and test for leakage and let ya know,


Timmy
 
Tim......I think that it just might be the H/E cap is loosing pressure on that engine. I'd either replace the cap or put recovery bottles on each engine. In any case I would replace the cap and check the flange that is on the H/E make sure it's not bent out of shape anywhere.
Good luck....Lee
 
re: coolant loss///////Think we got it

1. Finally put pressure tester on motor.

a. Pressure dropped fairly quickly

2. tightened up manifold/riser joint nuts and pressure loss stopped..........


3. Noticed rust stains under engine water pump and pulley (leaking water pump)

a. Will change before launching (thanks leokow)


Thanks to all,

Timmy
 
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