Heat exchanger problems yet again!

Carmel2

Well-Known Member
Joined
1 Jan 2005
Messages
12,609
Location
The possibilities are endless.
Visit site
So, new hot water boiler and all pipe fittings, new head gasket, heat exchanger cleaned and skimmed, new gaskets all over the place. It starts leaking bright green coolant via the overflow on the heat exchanger, new end caps and new exhaust elbow, only one thing left to my mind: new pressure cap. Source that, off we go, and now we are now pissing out purple liquid from the overflow and the only thing I can think of that is red is the reverse oil, but that makes no sense!

Edit: It's a Volvo Penta MD2040D

Any thoughts for someone who is on the verge of just walking away and saying fuck it!

 
Last edited:
So, new hot water boiler and all pipe fittings, new head gasket, heat exchanger cleaned and skimmed, new gaskets all over the place. It starts leaking bright green coolant via the overflow on the heat exchanger, new end caps and new exhaust elbow, only one thing left to my mind: new pressure cap. Source that, off we go, and now we are now pissing out purple liquid from the overflow and the only thing I can think of that is red is the reverse oil, but that makes no sense!

Edit: It's a Volvo Penta MD2040D

Any thoughts for someone who is on the verge of just walking away and saying fuck it!


Slightly confused by your reference to the colours being ejected , is that a typo as its three different colours - green - red - purple ? ?

anyways im assuming you have run the engine upto temperature ?
what temperature did it attain before overflowing ?
assume you have cooling water flowing through the sea water strainer and exiting the exhaust ?
do you have a gearbox or engine oil cooler in the line ?
have you a bleed point to remove any air trapped in the system ? (usually highest point)
any air lock in the system will cause localised boiling in the cooling jacket and a quick suge in pressure as the water boils and ejects via the overflow
can you isolate and remove the water heater as a test or any other oil coolers and run the engine without them IE simplify it and then add them back in one at a time?

just s few thoughts to be going on with , hope it helps
 
Q,"Slightly confused by your reference to the colours being ejected , is that a typo as its three different colours - green - red - purple ? ?"

A,Sorry on the colours. We are using Volvo coolant which is green, but the liquid coming out of the overflow is not green but purple. The transmission oil (ATF Dexron III) for the reverse gear is red.

Q,"anyways im assuming you have run the engine upto temperature ?
what temperature did it attain before overflowing ?"

A, I don't have a temp gauge but yes it was brought up to temperature and no alarms went off

Q,"assume you have cooling water flowing through the sea water strainer and exiting the exhaust ?"
A, Yes

Q, "do you have a gearbox or engine oil cooler in the line ?
have you a bleed point to remove any air trapped in the system ? (usually highest point)
any air lock in the system will cause localised boiling in the cooling jacket and a quick suge in pressure as the water boils and ejects via the overflow"

A, I don't know if it has a bleed point. Would running it up to temp with the pressure cap off work? I think it's an engine oil cooler in the line hence the Dexron.

Q,"can you isolate and remove the water heater as a test or any other oil coolers and run the engine without them IE simplify it and then add them back in one at a time?"

A, Yes I can isolate the hot water boiler, but it is brand new INC all the fittings and pipe work.

Just a thought on the purple liquid, with this being a new cap, could that have been greased, the spring or any other part with a red grease??

Thanks for you help..
 
ok

there was a post here recently re lidls selling a laser temp guage hand held unit - i use them all the time for tracking cooling problems (not lidls one but similar im sure), if you have no temp guage and you can get a laser one for 30 quid it will help isolate the problem

can you check the gear box for oil loss ?

yes running with the cap removed MAY help remove any trapped air - run the engine for a brief spell 10-15 mins and leave the cap off to see if the water is drawn in as the vaccum inside colapses when the engine cools - it might work ,

look for a bolt or small tap in the top of the heat exchanger (they dont all have it) if you undo it make sure engine is cold, you may find similar on the fresh water cooling as well

what height is the water heater ? calorifier ? if its higher than the engine you may find pulling the hoses off there and "back filling" the cooling system helps - if the rad cap or expansion tank isnt the highest point air will simply stay where it is

the colour change is odd - what colour was the old antifreeze before you drained the system ?

the grease from the cap wouldnt break down in water
 
Check your not over filling it , check that there no creamy colouring in the cooling water, you said you changed all the pipes , I once had the same problem with a Volvo 2040 and it was the pile going to the boiler which where partly block but if you change them then it can't be that .
run the engine with the cap off and see if there any presser in the top up tank ,
Check gearbox oil .
Did the problem start before you changed the pipes , ?
Have you get a kink in one of the pipes ?
www.bluewatersailorcroatia.webs.com
 
Last edited:
the colour change is odd - what colour was the old antifreeze before you drained the system ?

The coolant/antifreeze is bright green but what is coming out of the overflow is purple. At the moment it is too hot to take off.

iqbsex.jpg


This is the heat exchager and as far as I can see no bleed nut.

http://www.marinepartseurope.com/en/volvo-penta-explodedview-7740690-26-4077.aspx
 
Check your not over filling it , check that there no creamy colouring in the cooling water, you said you changed all the pipes , I once had the same problem with a Volvo 2040 and it was the pile going to the boiler which where partly block but if you change them then it can't be that .
run the engine with the cap off and see if there any presser in the top up tank ,
Check gearbox oil .
Did the problem start before you changed the pipes , ?
Have you get a kink in one of the pipes ?
www.bluewatersailorcroatia.webs.com

If I run it with the cap off how will I know about the pressure? Yes the problem did start before the pipes were changed but that was put down to a blown head gasket and it certainly wasn't purple. Will check gearbox, and no kinked pipes as far as I can see.

Thanks for the input!!
 
the colour change is odd - what colour was the old antifreeze before you drained the system ?

The coolant/antifreeze is bright green but what is coming out of the overflow is purple. At the moment it is too hot to take off.

iqbsex.jpg


This is the heat exchager and as far as I can see no bleed nut.

http://www.marinepartseurope.com/en/volvo-penta-explodedview-7740690-26-4077.aspx

was the head sent to a machine shop and pressure tested or dye tested for a crack - could that be the cause of the colour change ?

you really need to know what temperature the engine is achieving before it over pressurises ?

there is a dye available and a suction pump that draws the "smoke" from the cooling system rad cap - if it detects co2 in the "smoke" it changes colour -( compression gasses shouldnt be present in the coolant ) it would tell you if there was still a problem with the head gasket - may not have been a head gasket in the first place - think chicken and egg scenario- head gasket blew because of a fault elsewhere ? if it wasnt a head gasket blown a crack will give similar problems - hence we always pressure test them save wasting time doing gaskets only to discover a crack three days later when its still playing up.

has the Dxtron level dropped ? we have some here on ship somewhere ill see if it mixes with water - i cant imagine it , but ill look in the morning 18;00 here and im off shift and off to bed

mean while run it for fifteen mins (ish) at low revs with the cap off and let it cool for a couple of hours , see if it draws water into the block, it could simply be an air lock BUT that doesnt explain the red colour if your anti freeze was green
 
You should be able to tell if there is a pressure by rev up the engine and looking at the water in the tank , there will be some moment but it shouldn't be bubbling up , remove cap from the header tank before heating up the engine or it will just blow hot water and stream out if you remove it after wards , ( ok I might be teaching a duck to swim , but rather let you know just in case you don't know ) .

If you are short of oil in the gearbox then it means it might be leading into the cooling system .
I think you on the way to Ragusa ? .
if so there a good guy who works on Volvo .

Ps

You could try one other thing , drain all the water out of the system and flash it thought , then just add clean water only no cooler and run the engine for a while and see if you still get the discolour , that way you will have a better idea of the colour to start with and where it may be coming from .

www.bluewatersailorcroatia.webs.com
 
Last edited:
Thanks guys for all the help I think tomorrow is another day, everything should have cooled down by then, Vic I am going through Ragusa on to Licata any one worth a recommend in Licata?

We was in Licata last winter and to be honest the few jobs I heard of wasn't that good , one I had to redo for the guy , but there is a yard about 10 mins walk from the marina it might be worth having a word there or have a word with the chandlers out side the marina . Best chandlers to use for parts and cheaper then the one in the marina even with his 20% discount that he gives .

If I was you I start from the begin , you seeming so many different colour now , I drain it like I said and flash it out . At less then you be able to see what's going on ,
Water in the engine oil or gear oil would normally show up in a cream colour . I can't remember having a bleed nipple on my old 2040 and I not sure it would be air , you may have a blockage somewhere maybe in the coil in the boiler . The colour has got me puzzled , that why I think you better off flashing it out , then replace the cooler once you found the problem .

good luck

www.bluewatersailorcroatia.webs.com
 
Last edited:
Carmel you have my sympathy.
Same problem when I changed the calorifier hot feed.
It's probably down to having had old coolant in the calorifier, put in the new coolant, had an air-lock.

In the end I said "bu88er it" ran the engine, until it bubbled allowed it to cool and refilled (@ overflow reservoir and heat-exchanger cap).
From memory I did that 5 times until the air lock went and now all has been well for 1000 hrs.
 
Carmel you have my sympathy.
Same problem when I changed the calorifier hot feed.
It's probably down to having had old coolant in the calorifier, put in the new coolant, had an air-lock.

In the end I said "bu88er it" ran the engine, until it bubbled allowed it to cool and refilled (@ overflow reservoir and heat-exchanger cap).
From memory I did that 5 times until the air lock went and now all has been well for 1000 hrs.

Charles , I think what Carmel is worried about is that his cooler is green and the colour of the stuff that's coming out is red , and he is worried it coming from his gear box ,( ATF ) that's why I suggested he flush out the system first A it will get rid of any thing that may be lingering around and making the water change colour ( peace of mind it not an oil contamination from gear box ) although I would expect just by feeling it you know if the water had oil in it and B it help to flush out any air in the system . Another way to flush out air is to loosing highest hose his has so it drip out until all the air is out and keep topping up but that a very messy way . He can also squeaky the hoses sometime that will help to shift air but the stat need to be open , if he not done it yet , he also need to make sure all the clips are tight ,

www.bluewatersailorcroatia.webs.com
 
Last edited:
Charles , I think what Carmel is worried about is that his cooler is green and the colour of the stuff that's coming out is red , and he is worried it coming from his gear box ,( ATF ) that's why I suggested he flush out the system first A it will get rid of any thing that may be lingering around and making the water change colour ( peace of mind it not an oil contamination from gear box ) although I would expect just by feeling it you know if the water had oil in it and B it help to flush out any air in the system . Another way to flush out air is to loosing highest hose his has so it drip out until all the air is out and keep topping up but that a very messy way . He can also squeaky the hoses sometime that will help to shift air but the stat need to be open , if he not don't it yet he also need to make sure all the clips are tight ,

www.bluewatersailorcroatia.webs.com

Two different dyes in the premix coolant had that effect with me - if oil contamination I doubt he'd miss that.
In my case the engine coolant was 4 litres and the calorifier another 5. Quite an imbalance. That was after I'd "filled" the system from it's highest point.
 
if oil contamination I doubt he'd miss that.
Yes I agree , but not seeing it for my self I don't know for sure .
There other problem he need to check like the stat , if it running too hot , but he not said that it is .
When I had the problem on my moody years ago it was the coil that was causing the problem , and I only found it after I checked every thing else , sod law . But Carmel has a new boiler so it won't be that . Just thinking about it there also another way he could get air out , by the cooling temperature sensor,

www.bluewatersailorcroatia.webs.com
 
Last edited:
was the head sent to a machine shop and pressure tested or dye tested for a crack - could that be the cause of the colour change ?

you really need to know what temperature the engine is achieving before it over pressurises ?

there is a dye available and a suction pump that draws the "smoke" from the cooling system rad cap - if it detects co2 in the "smoke" it changes colour -( compression gasses shouldnt be present in the coolant ) it would tell you if there was still a problem with the head gasket - may not have been a head gasket in the first place - think chicken and egg scenario- head gasket blew because of a fault elsewhere ? if it wasnt a head gasket blown a crack will give similar problems - hence we always pressure test them save wasting time doing gaskets only to discover a crack three days later when its still playing up.

has the Dxtron level dropped ? we have some here on ship somewhere ill see if it mixes with water - i cant imagine it , but ill look in the morning 18;00 here and im off shift and off to bed

mean while run it for fifteen mins (ish) at low revs with the cap off and let it cool for a couple of hours , see if it draws water into the block, it could simply be an air lock BUT that doesnt explain the red colour if your anti freeze was green

Ok , checked it with TQF (its same as dextron) red in colour and doesnt mix with the water in any way (didnt think it would) , so no idea where your "colour " is coming from.

Question: what were the original symptoms that led you to believe you had a head gasket failure?


If the head was pressure tested and if necesary skimmed and assuming you torqued all components down correctly I would say its down to an air lock, and as i suggested before, back fill it from the highest point with the rad cap off, connect it all up run the engine ten to fifteen mins with the cap off, then let the engine cool , as it cools and the heat disipates it will draw coolant back into the engine and expell the air, you may need to do this several times as someone else has suggested.

if all else fails try Jack Daniels - the new honey mix is devine
 
Paul, to establish whether the problem has anything to do with the calorifier, i suggest you,do as we did previously. Disconnect the calorifier hoses from the engine, bridging the two nozzles with the length of red hose that you probably still have (!). Leave the domestic water pump on and check any discharge from the calorifier hoses. If nothing after half an hour then the problem lies elsewhere.

Because your calorifier is low in the boat I suspect that an air lock in it is not the problem but it could be worth back-filling it by pouring water into the hose that leads to the lower coil connection and removing the hose from the upper one. When water/coolant comes from the upper nozzle the coil is full.

Can't help with the colour, but oil contamination cannot be the cause, for reasons explained above but also because the coolant is at pressure, 12 psi? but the gearbox is not.
 
Ok , checked it with TQF (its same as dextron) red in colour and doesnt mix with the water in any way (didnt think it would) , so no idea where your "colour " is coming from.

Question: what were the original symptoms that led you to believe you had a head gasket failure?


If the head was pressure tested and if necesary skimmed and assuming you torqued all components down correctly I would say its down to an air lock, and as i suggested before, back fill it from the highest point with the rad cap off, connect it all up run the engine ten to fifteen mins with the cap off, then let the engine cool , as it cools and the heat disipates it will draw coolant back into the engine and expell the air, you may need to do this several times as someone else has suggested.

if all else fails try Jack Daniels - the new honey mix is devine


It started last year. I was running the engine on quite low revs (1500-1800rpm) because we have added a lot of weight to the boat: an inbuilt 4.5kw generator, watermaker, 100 metres of 10ml chain, a gantry with 4 panels, 100 metres floating line, kedge anchor, plus we have 70 kg of rib and outboard strung up. So less revs, less stress. Then we happened to be talking to an engineer who said we should be running it at 2500rpm, so we did. Soon after we started seeing coolant coming out the overflow so did the test that Vyv mentions and no problem. We found if we ran the engine at very low revs it didn't leak. Once back in port for the winter, the engineer we use came to see, took the pressure cap off and ran it up to temperature, and the coolant was bubbling, so he diagnosed a blown head gasket. It was taken apart and sent to Volvo in Athens to be milled flat and cleaned out. The heat exchanger was pressure tested to 1 bar, not dye tested. The injectors were cleaned, all new gaskets and rubber end caps, exhaust elbow, new calorifier, with all new pipe work and fittings. So we set off this year and had no worries until the last but one journey when the bright green coolant leaked from the overflow. So we sourced a new cap as that was the only thing that hadn't been replaced. We went off again and that was when the purple liquid started coming out of the overflow, so back to port. Below is a pic of the cap I took off this morning, you can see the red/purple on the bit where the cap sits and in the coolant. In the engine bay this morning the liquid has not separated, it's still the same as the photo. If it was the gear oil, or indeed any oil, I would have thought it would have separated.

This morning I tried get the bolt out of the gear box that acts as a dipstick. You can undo it to the point you can do it with your fingers and you feel it's loose, but go a quarter turn and it tightens. So, back with the socket wrench and 3 or 4 more turns and it's loose again but the same thing happens and after 50 or 60 turns it still doesn't come off, just the same thing over and over again. It tightens up ok, is it threaded?


ir8evm.jpg
 
Top