Volvopenta D1-30 losing coolant, reservoir cap puzzel.

tid2021

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Hi I hope I'm in the right place for my question. I have a Volvopenta D1-30 and recently it started losing coolant. I have had;
1. The intercooler out, acid cleaned, pressure tested which can back all ok no defective tubes.
On testing the engine it still lost coolant?
2. I have disconnected and isolated the water heater.
On testing the engine I noted that when the reservoir cap is screwed on tight the level goes down but when the cap is left lose the liquid level remains the same. Also there is what appears to be a small amount of coolant (and maybe air) coming out of the what I would call the "breather" pipe from the top of the interchanger jacket. I ran the engine for 1hr at tickover and then for 1 hr at 2000rpm and everytime when tighening the cap the level goes down.
I read in one of the Volvopenta D1-30 manuals that the coolant is circulated under slight pressure, if the pressure gets too much there is a pressure relief system in the cap, could this be the problem?
My questions are
1. Has any other D1-30 owners had this problem? if so what was the solution?
2. Any suggestions why when the cap is tight the liquid goes down and when lose stays as is?

This is driving me round the bend, and of cause all the Volvo service people are busy

I am sorry if I am missing the obvious here.
Thanks and regards
 

jamie N

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Welcome to the forums.
Possibly of no help at all, but what do Volvo mean by "slight" pressure? Mine's not a Volvo, but has fresh water cooling with an unpressurised header tank, which works perfectly. From what you say, it perhaps points to a blocked breather causing the pressure relief cap to activate too early.
Is it causing the engine problems?
You're in the right place to get better info by being here, as I'm sure many will have specialist knowledge
 

oldharry

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Nearly all cooling systems work under some pressure except raw water. Is there any frothing or bubbling in the coolant? If so the head gasket is leaking. Otherwise you have leak which only manifests when the system pressurises and forces coolant out. This could be a worn seal on the water pump for example. A slow leak can be very difficult to trace as often the fluid evaporates almost immediately from a hot engine. An internal leak is more serious as it will contaminate the oil which starts looking like mayonnaise and damages the internals.
 

RichardS

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I don't have a D1-30 but do you have a pipe at the side of the filler cap and is the coolant being lost out of the pipe. Fasten a small container under the pipe and collect any coolant and see is that amounts to your loss. Does your pressure cap have two valves in it? One to let excess pressurised coolant to exit the system and a valve in the middle to allow it the be sucked back in when the engine cools and the pressure reduces. If it is the latter, you should have an expansion tank with a dip tube which collects the ejected coolant and then allows it to be sucked back.

It all depends upon how your cooling system is designed to operate but at least if you collect any ejected coolant you will know whether that is the source of the loss or whether you have another source of loss such as the water circulation pump, the heat exchanger or the head gasket.

Richard
 
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VicS

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I don't have a D1-30 but do you have a pipe at the side of the filler cap and is the coolant being lost out of the pipe. Fasten a small container under the pipe and collect any coolant and see is that amounts to your loss. Does your pressure cap have two valves in it? One to let excess pressurised coolant to exit the system and a valve in the middle to allow it the be sucked back in when the engine cools and the pressure reduces. If it is the latter, you should have an expansion tank with a dip tube which collects the ejected coolant and then allows it to be sucked back.

It all depends upon how your cooling system is designed to operate but at least if you collect any ejected coolant you will know whether that is the source of the loss or whether you have another source of loss such as the water circulation pump, the heat exchanger or the head gasket.

Richard
I dont think its like that
ITYWF it's the same type of pressure cap as this where the apertures marked "B" are the vents, (Standard pressure cap on older Volvo cars)
Pressure cap vents.jpg
The brass insert incorporates both pressure and vacuum relief valves.
If it ejects coolant it just spills over the top of the expansion tank ....... messy and obviously no way the expelled coolant can be collected in an overflow vessel and sucked back again when the system cools.
 

tid2021

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Welcome to the forums.
Possibly of no help at all, but what do Volvo mean by "slight" pressure? Mine's not a Volvo, but has fresh water cooling with an unpressurised header tank, which works perfectly. From what you say, it perhaps points to a blocked breather causing the pressure relief cap to activate too early.
Is it causing the engine problems?
You're in the right place to get better info by being here, as I'm sure many will have specialist knowledge
Hi Jamie thanks I will check the breather pipe, the engine runs great just as it did before the problem started:confused:
 

tid2021

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Nearly all cooling systems work under some pressure except raw water. Is there any frothing or bubbling in the coolant? If so the head gasket is leaking. Otherwise you have leak which only manifests when the system pressurises and forces coolant out. This could be a worn seal on the water pump for example. A slow leak can be very difficult to trace as often the fluid evaporates almost immediately from a hot engine. An internal leak is more serious as it will contaminate the oil which starts looking like mayonnaise and damages the internals.
Hi Oldharry, thanks for your post and help. There is no frothing or bubbling in the coolant only a slight dribble from the breather pipe. I have notice an accumilation of water under the engine which now I know is coming from the water pump I have a service kit coming tomorrow. The engine oil was only changed two days ago and there was no milkiness (mayonnaise) of any kind.:confused:
 

tid2021

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I don't have a D1-30 but do you have a pipe at the side of the filler cap and is the coolant being lost out of the pipe. Fasten a small container under the pipe and collect any coolant and see is that amounts to your loss. Does your pressure cap have two valves in it? One to let excess pressurised coolant to exit the system and a valve in the middle to allow it the be sucked back in when the engine cools and the pressure reduces. If it is the latter, you should have an expansion tank with a dip tube which collects the ejected coolant and then allows it to be sucked back.

It all depends upon how your cooling system is designed to operate but at least if you collect any ejected coolant you will know whether that is the source of the loss or whether you have another source of loss such as the water circulation pump, the heat exchanger or the head gasket.

Richard
Hi Richard thanks for your reply and help. The only pipe is what seem to be a breather pipe from the top of the intercooler to the reservoir. The cap has no valves in it and I do not have a dip tube. There is no evidence of any liquid leaking from anywhere I can see:confused:
 

tid2021

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I dont think its like that
ITYWF it's the same type of pressure cap as this where the apertures marked "B" are the vents, (Standard pressure cap on older Volvo cars)
View attachment 119074
The brass insert incorporates both pressure and vacuum relief valves.
If it ejects coolant it just spills over the top of the expansion tank ....... messy and obviously no way the expelled coolant can be collected in an overflow vessel and sucked back again when the system cools.
Hi VicS thanks for your help and reply. Yes thats just like my cap except it does not have the brass center, now I am wondering if it is in the reservoir. Will have look tomorrow. Cheers
 

tid2021

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Hi All, following from my morning post and replies to all the knid people who have replied with suggestions and help.

Yesterday after running the engine I took the cap of the reservoir home to see if I could figure out the relief system.

I went to the boat today to replace the cap and to my horror the reservoir is empty, completly empty o_Oo_O. OK the coolant was hot when I left the boat yesterday but I cant imagin 1/2 - 3/4 ltr evaporating over night

So even more confused :confused::confused::confused:
 

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stuartwineberg

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Hi I hope I'm in the right place for my question. I have a Volvopenta D1-30 and recently it started losing coolant. I have had;
1. The intercooler out, acid cleaned, pressure tested which can back all ok no defective tubes.
On testing the engine it still lost coolant?
2. I have disconnected and isolated the water heater.
On testing the engine I noted that when the reservoir cap is screwed on tight the level goes down but when the cap is left lose the liquid level remains the same. Also there is what appears to be a small amount of coolant (and maybe air) coming out of the what I would call the "breather" pipe from the top of the interchanger jacket. I ran the engine for 1hr at tickover and then for 1 hr at 2000rpm and everytime when tighening the cap the level goes down.
I read in one of the Volvopenta D1-30 manuals that the coolant is circulated under slight pressure, if the pressure gets too much there is a pressure relief system in the cap, could this be the problem?
My questions are
1. Has any other D1-30 owners had this problem? if so what was the solution?
2. Any suggestions why when the cap is tight the liquid goes down and when lose stays as is?

This is driving me round the bend, and of cause all the Volvo service people are busy

I am sorry if I am missing the obvious here.
Thanks and regards
Can we just check what you mean by losing coolant. Do you mean it is boiling over and creating a pool under the engine or do you mean that you keep finding the reservoir empty but no overflow evidence? I note you have stripped the system down so you may have air trapped that is gradually working out.
 

RichardS

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Hi All, following from my morning post and replies to all the knid people who have replied with suggestions and help.

Yesterday after running the engine I took the cap of the reservoir home to see if I could figure out the relief system.

I went to the boat today to replace the cap and to my horror the reservoir is empty, completly empty o_Oo_O. OK the coolant was hot when I left the boat yesterday but I cant imagin 1/2 - 3/4 ltr evaporating over night

So even more confused :confused::confused::confused:
If you have lost that much coolant and there is no sign of it on or under the engine, then it must be finding its way out of the boat. The only exits are out of the exhaust or into the domestic water system. If there is no sign of any coolant in your hot water then it must be going out of the exhaust which either means across the interface in the heat exchanger or past the head gasket and into the oil system or into the combustion chamber and out through the exhaust.

If your engine is starting and running well and there is no water in the oil then I would expect that you have a leakage at the heat exchanger,

Richard
 

VicS

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Hi VicS thanks for your help and reply. Yes thats just like my cap except it does not have the brass center, now I am wondering if it is in the reservoir. Will have look tomorrow. Cheers
That's puzzling. It that is just a plain cap there must be another cap somewhere. A pressure control cap with the valves. Id expect then to be similar looking but one could be the " conventional " type as used by many cars for decades as "radiator caps. (See below) It that is the only cap then it should be a pressure control cap as in my photo. That's what I would expect to find on the reservoir. Item 1 in the picture of the engine

I am puzzled by your reference to an "intercooler" That implies that your engine is turbo charged but I can find no mention of a turbocharger anywhere. Do you really mean heat exchanger ?
Radiator cap.jpg

1626648607091.png
 

tid2021

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That's puzzling. It that is just a plain cap there must be another cap somewhere. A pressure control cap with the valves. Id expect then to be similar looking but one could be the " conventional " type as used by many cars for decades as "radiator caps. (See below) It that is the only cap then it should be a pressure control cap as in my photo. That's what I would expect to find on the reservoir. Item 1 in the picture of the engine

I am puzzled by your reference to an "intercooler" That implies that your engine is turbo charged but I can find no mention of a turbocharger anywhere. Do you really mean heat exchanger ?
View attachment 119119

View attachment 119120


Hi the attached is the same as my cap and was from the internet at

"Orbitrade 15083 Expansion Tank Pressure Cap for Volvo Penta Engines


Part No: ORB-15083

Orbitrade Marine pressure cap designed to replace Volvo part number 1674083. This pressure cap is for use with the engine cooling expansion tank in Volvo Penta marine engines."

I think you maybe correct regarding the terminology of "heat exchanger" and "intercooler". The engine isnt turbo charged so I suppose I should be using "heat exchanger". Thanks for the correction as maybe I have mislead others.
 

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tid2021

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Can we just check what you mean by losing coolant. Do you mean it is boiling over and creating a pool under the engine or do you mean that you keep finding the reservoir empty but no overflow evidence? I note you have stripped the system down so you may have air trapped that is gradually working out.
Thanks for your ideas and suggestions, the coolant isnt boiling over, I would say the temp of the coolant is normal even after running the engine for 1 hr you can touch the colant reservior with the palm of your hand for some time. There is no evidence of any leaks from the pipework system. I have had the heat exchanger out and tested and I have taken the water clarifier out of the system (diconnected the pipes from the clarifier and reconnected them together so there is still a circular flow in the cooling system).
I also though of air in the system but after the engine has been run for 2 hours I would have thought that any trapped air would have be evacuated.
 

stuartwineberg

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Thanks for your ideas and suggestions, the coolant isnt boiling over, I would say the temp of the coolant is normal even after running the engine for 1 hr you can touch the colant reservior with the palm of your hand for some time. There is no evidence of any leaks from the pipework system. I have had the heat exchanger out and tested and I have taken the water clarifier out of the system (diconnected the pipes from the clarifier and reconnected them together so there is still a circular flow in the cooling system).
I also though of air in the system but after the engine has been run for 2 hours I would have thought that any trapped air would have be evacuated.
Not necessarily. How many times have you topped up the expansion tank? Did you measure the total volume of coolant added after the strip down vs the recommended volume in the manual.
 

VicS

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Hi the attached is the same as my cap and was from the internet at

"Orbitrade 15083 Expansion Tank Pressure Cap for Volvo Penta Engines

Part No: ORB-15083
Thats OK
Just made with plastic encased internal gubbins ratter than brass like my "classic" part

If you fill the system to the normal level fit the cap and run the engine until warm

Then allow to cool, top up run again and repeat several times can you get to a stable situation where the level remains within normal limits ?

,
 

tid2021

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Not necessarily. How many times have you topped up the expansion tank? Did you measure the total volume of coolant added after the strip down vs the recommended volume in the manual.

Thanks agian for your continued interest and advice. I have topped up the reservoir three times, and several times just topping it up when running I think the system takes 5ltrs. I will top it up agian without running the engine and see what happens. Cheers
 

tid2021

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Thats OK
Just made with plastic encased internal gubbins ratter than brass like my "classic" part

If you fill the system to the normal level fit the cap and run the engine until warm

Then allow to cool, top up run again and repeat several times can you get to a stable situation where the level remains within normal limits ?

,
Thanks VicS again for your support, I will try doing this again although I have ran the engine several times and the level remains constant when the cap is not screwed on tight, but when tight the level drops. Cheers
 

Moodysailor

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Does the coolant appear in the bilge, or is it "disappearing"?

The pressure cap needs to be on - cooling systems run at around 4-7psi, this is done to raise the boiling point of the water so that no steam can be created in the engine during use (air is a poor conductor of heat).

I've only briefly skimmed through the posts, so may have missed something but if you are losing water and it's not in the bilges then, as mentioned above, it has to be going out through the engine. I'm also suggesting heat exchanger, the rubber end caps can be a source of leaks into the raw water system, which then exits out through the exhaust.
 

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