Volvo kad32 overheating ??

[the griff]

Just got back from a fishing trip in my 24' boat with a kad32.
After doing about a 60mile trip, we were just about to come back into the river mouth when the alarm started beeping, the engine was too hot!
I turned off the engine straight away and let it cool down for 20 minutes, topped the raw water cool side up with pink coolent and after about a minute doing around 5 knots it was too high again, I checked to see if the coolent had been pumped through and it had all gone so I knew the impeller was ok and that side of things was working ok.
Then I realised the sealed coolent system was completely empty, I know this should of been checked as soon as the problem started but after having an impeller problem previously I presumed it would be that again.
We filled the coolent system up with a tiny bit of Volvo green coolent and mainly fresh water, it glugged away until filled, started the engine and only doing around 5 knots made the couple of mile trip back to the river mouth, stopping half way to top the water up little bit again.
Once we started going up the river when we were in safe waters I slowly upped the speed to about 20 knots and all was well, we kept checking the coolent level and it was fine for the next 10 mile. I slowed down to radio the lock keeper and check to see if there was still enough water to let through the lock as we were now running late, it was touch and go so powered on at around 25knots to get there.
After a carry on getting the boat into the lock (tilting leg in trailor mode and all of us getting off to make boat sit higher, we managed to pull it in on ropes).
I checked the coolent level again before leaving the lock and it had dropped quite a bit, nearly to the bottom of the filling container, I topped it up again and managed to get it moored up around a mile later.

The oil has recently been changed and looks as it should, not milky or immulsified so hopefully not the head gasket.
I am presuming it's gone into the bilge but we spilt that much water topping it up I can't say for definite.
It's been a long day so will have to try and find the problem/leak in the morning but was wondering if anyone new of any known problem areas with the coolent side of things leaking or any places to start looking?
The problem I have is this engine compartment is designed for a smaller petrol engine and it's a nightmare to access around the engine.

After getting a 7/0 hook embedded in my arm and loosing a £200 rod and reel over the back of the boat this wasn't the ending to a days fishing I needed.

Thanks for any advice,

 

[neale]

I checked to see if the coolent had been pumped through and it had all gone so I knew the impeller was ok

The above statement is incorrect. The impeller circulates the raw water, not the coolant. I am also not sure that pink and green antifreezes are compatible. Usually the KAD32 uses Volvo Green stuff which is ethylene glycol. If you are losing coolant, and the oil is not milky and it is not ending up in the bilge, you may have a heat exchanger problem.

 

[the griff]

I know the impeller circulates the raw water side, I put pink coolent in it to check if it would disappear to confirm the raw water was working ok.
The green coolent in the other system after closer inspection today is going into the bilge, and the header tank that I filled yesterday had emptied over night.
Still not found where it's leaking from!

 

[Richardcm]

Out with the mirrors and the troch

 

[the griff]

Out with the mirrors and the troch

It's such a slow leak it's going to be difficult to find.
Maybe pressurising the system a bit with a pressure tester might help speed the leak up so its more noticeable where it's dripping?

 

[volvopaul]

It's such a slow leak it's going to be difficult to find.
Maybe pressurising the system a bit with a pressure tester might help speed the leak up so its more noticeable where it's dripping?

I'd look at the tank cap, and don't fill it above the low mark when cold.

 

[dragoon]

Does that engine heat the domestic water?

 

[the griff]

I'd look at the tank cap, and don't fill it above the low mark when cold.

Not quite sure what you mean, do you mean it might be leaking from the header tank cap that you unscrew where you would fill it?
It was at the full mark last night when I moored it up for the night and the header tank was completely empty this morning when I checked it, so even without the engine started if has lost a lot of water over night.

 

[the griff]

Does that engine heat the domestic water?

Yes the hot water was working and was hot when I was filling a bottle up with water to top the coolent up yesterday, I know because in the panick to get more water I switched the wrong tap on, although this water had been heating up on and off all day so could of still been hot from before the problem started!

 

[bammylovechops]

I agree with what was said said about NOT overfilling above the low level on the expansion box, I had the same same problem with water ending up all over the engine bay but keeping it to a maximum of the low level marker cured it, with no problem of over heating to the engine.

 

[the griff]

So are you saying by filling it too much it is too much for the system and its spitting it out because it can't cope, but when it spits it out it spits too much out causing it to overheat.
I filled it up before I left yesterday so will check tonight after work if level has dropped again, if it's empty again there must be a leek somewhere because engine was cold when I left it.
If still full I will try it on minimum and give it a blast up the river.

Thanks again for the help.

 

[captaindan]

I have had that happen on my kad 42 if it gets hot it will spill over , I think its designed too. I also had a leak on the bottle once and it was dripping out slowly wear I could not see it. I popped it off and used a plastic welder to fix it as vovlo wanted around 250 for a plastic tub.. I do know you should not mix the coolants and that you should use the correct coolant (green) recomended for the engine .

 

[the griff]

Just checked it after work, the header hasn't lost any more coolent.
I will put it on minimum and take it for a blast one night this week to see if that solves it.
It may be that it only leeks when it's hot or under pressure, but won't know until I have tried it.

Just to confirm, I have only ever used the green Volvo coolent in the system and never mixed any other coolent in with it. I only used the pink coolent to check the raw water cooled side of things which is a seperate system, I put it in to see if it disappeared to make sure the impeller was working, I also use the pink antifreeze/coolent in the raw water side when winterising it, I drain out the water using the plugs around the system, revmove the impeller, put impeller cover back on and pour antifreeze in it until it comes out of both the intake and outlet, this way I know any water stuck in a u bend will not freeze, a bit over the top but better safe than sorry.

 

[Jim@sea]

I dont suppose your boat is a Hardy 24.
The reason I ask is that I am considering what boat to buy next and a couple of years ago there was a Hardy 24 on the next pontoon to where I was and they were having all sorts of problems with the Volvo engine overheating,

 

[the griff]

It's a falcon spc23, not had any problems up until now with the engine in 8 years, all the problems over the years have all been electrical connections............or and a mouse nest in the supercharger!!

 

[Momac]

Take out the impeller and check for any damage. If bits of impeller are missing they may well be in the oil cooler and if so restricting the flow and causing overheatng.

edit
probably the intercooler not the oil cooler.

 

[the griff]

Take out the impeller and check for any damage. If bits of impeller are missing they may well be in the oil cooler and if so restricting the flow and causing overheatng.

Why would the restricting flow of the raw water cooled system make the sealed coolent side of things get too hot and loose coolent, does each system not cool different parts of the engine?
The impeller is fine and pumping water as it should, it's the coolent side that's the issue.

 

[Richardcm]

Sealed system cools the engine, raw water cools the sealed system, raw water restriction could cause sealed systm to run hot.

 

[Richardcm]

Why would the restricting flow of the raw water cooled system make the sealed coolent side of things get too hot and loose coolent, does each system not cool different parts of the engine?
The impeller is fine and pumping water as it should, it's the coolent side that's the issue.

Sealed system cools the engine, raw water cools the sealed system, raw water restriction could cause sealed systm to run hot.

 

[the griff]

Sealed system cools the engine, raw water cools the sealed system, raw water restriction could cause sealed systm to run hot.

Ok, last year I chewed a impeller up to the point there was no fins left on it. We thought we had got rid of all of bits but the basket type filter is a daft design, when you pull it out bits can escape down the low side of it, I wonder if that's what could of happened and there is still a bit of impeller in there somewhere?