coolant overheating

[bill j]

While at lake Powell last week, I ran the boat to 3980rpm (13.2 knots) for a few minutes and a warning message came up that the coolant was overheating. I instantly reduced speed and the alarm disappeared. I had 5 people aboard with camping equipment, but this is the only time I have noticed any problem with overheating. Throughout the 5 day trip, the oil temperature stayed exactly in the middle of the dial and never heated going 6-8 knots. Is this indicative of a problem with the impellar? If the impellar is such a critical element in the success of any boat trip, why is it made of rubber and so difficult to replace??? thanks for any advice - Bill

 

[Jake]

Not to get too far off subject, but on the 26, is the impeller kinda difficult, moderately difficult or extremely difficult to replace? Location? Access?
Thanks

 

[pleeson]

My apologies for not knowing the answer to your questions... On a separate topic, where did you launch and how did you find the water levels? I note that they are within inches of being too low to launch mid lake... Thanks.

 

[knotflying]

Bills,
Your post has two different items, in one you are talking about water temperature and the other oil temperature. Are you talking water temperature or oil pressure. Please clarify.

 

[bill j]

When I ran the boat hard, the coolant temperature alarm came on. When I ran slower at 7 knots, the alarm went off and the oil temperature stayed in the middle of the dial throughout the remainder of the 4 day trip. I never saw the oil temperature rise. does this sound like an impeller issue or something more serious?? thanks for the help - Bill

 

[knotflying]

Bill,

I see you have a Cutwater. Is it a Yanmar or a Volvo. I ask that because you refer to oil temperature and I am not familiar with the Yanmar having a oil temperature sensor. Perhaps the Volvo does. In your question you first refer to the coolant temperature alarm sounding off and say nothing about an issue with the oil. In your second statement you are then referring to oil temperature. Is there an issue with the oil temperature when the coolant alarm sounds?

 

[dencarst]

Hi

On my R27 it also overheated found problem was low coolant in the engine and the reservoir show full.
Added antifreeze and problem went away.

Dennis
Tug of my Heart11

 

[bill j]

D3 Volvo engine in the Cutwater. No - the coolant temperature alarm went off but the oil temperature did not change or elevate; the indicator remained in the middle of the dial. - thanks

 

[Levitation]

Dennis - I'm a bit puzzled. If the overflow canister was up to the mark (or full) how would the engine lack coolant?
And how did you get it to accept more coolant when the canister was full or nearly full?
I suspect I am misreading your description :mrgreen:

 

[Levitation]

And to the OP - first thing let's kill all the lawyers.
ooooops - wrong topic. (not a bad idea though)

First thing let's change the impeller.
Now ease of access, like beauty, is in the eye of the beholder. I haven't beheld the pump[ on that boat so I'll await your opinion.

 

[Gin]

As a Shakespeare fan, I'd like to set the record straight. The line ''The first thing we do, let's kill all the lawyers,'' was stated by Dick the Butcher in ''Henry VI," who was among those who wanted a rebel dictatorship. Killing the lawyers was a way to overthrow justice and the rule of law. Just for the record 🙂

Gini

 

[knotflying]

Dennis - I'm a bit puzzled. If the overflow canister was up to the mark (or full) how would the engine lack coolant?
And how did you get it to accept more coolant when the canister was full or nearly full?
I suspect I am misreading your description :mrgreen:

You do not add more antifreeze via the overflow tank, it must be added directly to the radiator by removing the cap. The overflow is for expansion and contraction of the antifreeze when it gets hot and cools. If you are low on fluid adding it to the overflow does not allow it to fill the radiator. If you are low on antifreeze and it keeps happening then there is a leak somewhere. If the Cutwater has the same cabin heater as the Ranger that is many times the culprit at the connections to the heater. Just tighten the clamps. Then there will be the connections at the water heater and then where the hoses come off the engine. If tightening the hose clamps does not work then a pressure test will confirm a leak and then it could be a pin hole in a line somewhere.

 

[Don Cardinal]

A possible cause of some of the coolant overheating problems, low coolant mixture in the cooling system, high liquid level in overflow tank, may be.

Look for loose connections in the tubing from the cooling system pressure cap area to the overflow tank.
Look for cracks or holes in the tubing.
Check that the dip tube in the expansion tank is still attached in the overflow tank and that there are no cracks in that tube or what it is attached to.

If there is an air leak in the above plumbing, It is possible that your problem is that leak.
Consider that your coolant expands as normal when the engine is run..
Some fluid goes to the expansion / overflow tank.
The engine cools slowly after shut down.
Normally this cooling of the coolant causes a vacuum in the cooling system pulling coolant back and keeping it full.
If you have a leak in the recovery system, air will draw into the system instead of the coolant that was supposed to keep the cooling system full. (path of least resistance)
You use the boat again, The same expansion and contraction takes place.
As the level of coolant drops in the cooling system and over several run cycles the engine may run hotter expanding even more fluid into the recovery tank.
You now may have a low coolant level in the engine but a high level in the recovery tank.

Hope this helps, Just thinking
Don

 

[pleeson]

Hope you solved your problem. A mystery coolant leak had our coolant alarm going off every couple of days on out Volvo D 4 in a Cutwater 28. Went through about a gallon of coolant over a couple of week long cruises. Finally found loose coolant hose connections on the water heater tank! Tough to find when it drains to the bilge area.