Technical Changing the Radiator Coolant

[mike800966]

I'm ashamed to say that I completely overlooked changing the radiator coolant! 106000miles!!
Just noticed that the expansion bottle is got more and more stained and decided it was time to ask a question.
1 Whats the fill volume is it 5l plus deioniesed water? or do i just get 2x5l of RTU stuff?
2 whats all this about not compatible coolants, its always just seemed a brownish colour to me
I dont have any other way to find whats the right coolant for the 2.8jtd 8140.43 engine

I'm sure someone wil know
Big Thanks

Mike S

 

[Mike1alike]

Hi Mike,
Fill volume: For the 2.8 JTD 8140.43, the system is roughly 10 litres total. You can use pre-mixed (RTU) coolant, or concentrate diluted with deionised water (50:50) — just make sure you reach the correct fill line in the expansion tank.
Coolant type/compatibility: Fiat 2.8 JTD engines require OAT (Organic Acid Technology) coolant, usually blue or greenish-blue. Avoid universal “brown” or old silicate-based types — mixing incompatible coolants can cause corrosion, gelling, or blockages over time. Stick to Fiat-approved or equivalent spec.

Extra tips:
Flush the system. The coolant is very old. Very very old!
Fill and bleed carefully to avoid air pockets (heater on, engine warm, top up slowly).

 

[Mike1alike]

Here is a useful guide about flushing the cooling system

I fixed the car heater (little radiator inside the car) | FIAT Punto (Mk2/2b)

Hello everyone, I will share with you this great fix, for the case your heater is not working but cooling system works fine, engine temperature is steady good and thermostat works fine. So everything works just fine, then winter comes alog and you have no heat inside the car. And also, it's...

www.fiatforum.com

 

[Communicator]

As there is no drain cock, or plug in the cooling system, do not overlook the difficulty of removing the old coolant. Removing a radiator hose is perhaps the best option, but these are secured with proprietary clips, which probably need an expensive tool to remove them. I sawed through those on my vehicle, but access is restricted. I used a suitably sized, under bed plastic storage box, to drain into, and caught most of the old coolant. As to coolant type and refilling Fiat eLearn for the x244 may be viewed here.

While I do not think that it matters in the present context, it may be useful to note that a Sofim 8140.43, would refer to the earlier 2.8idTD, with mechanical injection. The correct designation for the 2.8jtd is 8140.43s. Note the suffix "s".

 

[mike800966]

As there is no drain cock, or plug in the cooling system, do not overlook the difficulty of removing the old coolant. Removing a radiator hose is perhaps the best option, but these are secured with proprietary clips, which probably need an expensive tool to remove them. I sawed through those on my vehicle, but access is restricted. I used a suitably sized, under bed plastic storage box, to drain into, and caught most of the old coolant. As to coolant type and refilling Fiat eLearn for the x244 may be viewed here.

While I do not think that it matters in the present context, it may be useful to note that a Sofim 8140.43, would refer to the earlier 2.8idTD, with mechanical injection. The correct designation for the 2.8jtd is 8140.43s. Note the suffix "s".

Thank you all for the advice. I am still a bit nervous about changing the coolant which is a reddish brown colour as filled from new!! 2005 build!!. Its because my Dad (bless his departed socks!) would always be reluctant to add antifreeze to the cooling water because he said it would find any leak!. Nowadays engines run in antifreeze all year round.
So are you saying the brown stuff would be the original before OAT tech came along? I have the special pliers to release the hose clips but would rather replace them with worm drive ones.
BTW it is the electronic direct injection as it has push on caps to each cylinder rather than HP Metal pipes
Thanks all
Mike S

 

[Communicator]

@mike800966

Hi Mike,
This matter has been niggling at the back of my mind for a few days, but as both my wife and I are trying to recover from Covid or something similar, I have not been quick off the mark.

I only partly changed the coolant in my 2006 2.8jtd a few years ago. The coolant as in your vehicle the coolant is red, not blue, and the niggling thought was that I had previously read a discussion about it on perhaps the OAL forum many years ago. So far no success with searches. Today I felt well enough to wrap up, and enter a cold MH in a cold garage, to retrieve the Drivers Handbook.

On page 170 there is a small section in bold type. "Top up only with the same fluid contained in the cooling circuit. PARAFLU UP (red) cannot be mixed with PARAFLU II (blue) or other fluids. Should this happen, do not start the engine and contact Fiat Dealership."

The conclusion is that both of our vehicles contain PARAFLU UP. The two alternatives are also listed in the Capacities Section on page 240.

Fiat eLearn only mentions PARAFLU 11 in connection with refilling the system.

I cannot remember what I diluted for topping several years ago. I doubt that it was PARAFLU UP, but probably Glysantin G30, which is also a red OAT based mixture, as I have that available for our Skoda.

 

[bugsymike]

According to my Autodata after 2002 the common rail JTD held 12 litres of coolant so minimum of 6 litres of pure antifreeze when you decide which type.
As long as old coolant is well flushed out then you can use which ever you prefer. OAT started to be used mid 1990s, in most cases if coolant looked clean then it would be tested for strength using the appropriate tester and topped up with more antifreeze if required before then.
Down here in sunny Devon the water has always been used out of the tap (not dionised) as kettles and irons etc. don't get limescale here etc.and long term experience of servicing regular customers vehicles over many years has shown no ill effects. Same with topping up batteries when you used to be able to.
Incidentally any engine with aluminum parts(JTD cylinder head) should have antifreeze all year round regardless of climate as it includes a corrosion inhibitor.
Another reason coolant can be brown is where it has never been changed and is silted up blocking radiator cooling tubes and cylinder block.

 

[AnthonyH]

Thank you all for the advice. I am still a bit nervous about changing the coolant which is a reddish brown colour as filled from new!! 2005 build!!. Its because my Dad (bless his departed socks!) would always be reluctant to add antifreeze to the cooling water because he said it would find any leak!. Nowadays engines run in antifreeze all year round.
So are you saying the brown stuff would be the original before OAT tech came along? I have the special pliers to release the hose clips but would rather replace them with worm drive ones.
BTW it is the electronic direct injection as it has push on caps to each cylinder rather than HP Metal pipes
Thanks all
Mike S

I bought my punto EVO at 90,000 miles and the coolant was a muddy brown colour, rather than red. I drained that and put new coolant in only to discover it turned muddy brown almost immediately lol. I should have flushed but never got around to it. 40,000 miles later i've had no noticeable ill effects. The browny colour is caused by rust. My point being...its time to change the coolant for sure, but if you aren't going to flush the radiator and pipes you can expect the muddy colour to come straight back

 

[bugsymike]

I bought my punto EVO at 90,000 miles and the coolant was a muddy brown colour, rather than red. I drained that and put new coolant in only to discover it turned muddy brown almost immediately lol. I should have flushed but never got around to it. 40,000 miles later i've had no noticeable ill effects. The browny colour is caused by rust. My point being...its time to change the coolant for sure, but if you aren't going to flush the radiator and pipes you can expect the muddy colour to come straight back

Yes, well worth flushing if like that, as the radiator tubes start to clog and then engine runs hotter. Next thing then is a head gasket issue which if radiator not sorted then becomes another head gasket issue. Usually the method is to "back flush" in other words against the normal flow of the coolant, this brings more of the sediment out.

 

[AnthonyH]

Yes, well worth flushing if like that, as the radiator tubes start to clog and then engine runs hotter. Next thing then is a head gasket issue which if radiator not sorted then becomes another head gasket issue. Usually the method is to "back flush" in other words against the normal flow of the coolant, this brings more of the sediment out.

The OP appears to be saying his dad owned the vehicle beforehand and only every topped up the coolant with water, so over the years the antifreeze has gotten progressively more diluted. Its just aswell the system didn't develop any kind of leak because it may have then turned to 100% water and rusted through something expensive

 

[bugsymike]

The OP appears to be saying his dad owned the vehicle beforehand and only every topped up the coolant with water, so over the years the antifreeze has gotten progressively more diluted. Its just aswell the system didn't develop any kind of leak because it may have then turned to 100% water and rusted through something expensive

Many in the old days didn't take antifreeze seriously, I suppose if vehicle was garaged during Winter months he would have got away with it not freezing and cracking the engine block etc.Another thing motorists did back then was drain the radiator and cooling system so it wouldn't damage if it froze. Sounds like a lot of work instead of antifreeze.
I recall as an apprentice late 1960s a car came in one Winter and on inspection it had frozen so badly the engine block has cracked and was scrap, the owner had a new engine fitted at great expense and was then asked if he wanted antifreeze? To which he replied "Oh no, lightening doesn't strike twice! So some people cannot be helped.

 

[Communicator]

According to my Autodata after 2002 the common rail JTD held 12 litres of coolant so minimum of 6 litres of pure antifreeze when you decide which type.
As long as old coolant is well flushed out then you can use which ever you prefer. OAT started to be used mid 1990s, in most cases if coolant looked clean then it would be tested for strength using the appropriate tester and topped up with more antifreeze if required before then.
Down here in sunny Devon the water has always been used out of the tap (not dionised) as kettles and irons etc. don't get limescale here etc.and long term experience of servicing regular customers vehicles over many years has shown no ill effects. Same with topping up batteries when you used to be able to.
Incidentally any engine with aluminum parts(JTD cylinder head) should have antifreeze all year round regardless of climate as it includes a corrosion inhibitor.
Another reason coolant can be brown is where it has never been changed and is silted up blocking radiator cooling tubes and cylinder block.

I still have the Fiat "Owner Handbook" immediately to hand. On page 240, the cooling system capacity for the 2.8jtd is given as 10 litres, so only 5 litres of concentrate required.

 

[bugsymike]

I still have the Fiat "Owner Handbook" immediately to hand. On page 240, the cooling system capacity for the 2.8jtd is given as 10 litres, so only 5 litres of concentrate required.

Fiat should know, although it does appear to depend on the age. Apologies as usual for the photo quality.
Personally better too much than not enough when it freezes.

 

[AnthonyH]

Many in the old days didn't take antifreeze seriously, I suppose if vehicle was garaged during Winter months he would have got away with it not freezing and cracking the engine block etc.Another thing motorists did back then was drain the radiator and cooling system so it wouldn't damage if it froze. Sounds like a lot of work instead of antifreeze.
I recall as an apprentice late 1960s a car came in one Winter and on inspection it had frozen so badly the engine block has cracked and was scrap, the owner had a new engine fitted at great expense and was then asked if he wanted antifreeze? To which he replied "Oh no, lightening doesn't strike twice! So some people cannot be helped.

In the olden days i too used to fill the radiator with water, either sometimes or always, its too long ago for me to determine whether i caused a serious mishap because of that.

What i do remember is that in December 2009 i went for a holiday to Australia without turning the water off at the mains. The pipes froze, cracked and flooded the house...

 

[bugsymike]

What i do remember is that in December 2009 i went for a holiday to Australia without turning the water off at the mains. The pipes froze, cracked and flooded the house...

I did the opposite, went skiing in Italy with first wife, turned off the mains water , when I got back I found that it also turned off half the street as houses were 200 years old farm labourers cottages.

 

[Ocwobio]

Thank you all for the advice. I am still a bit nervous about changing the coolant which is a reddish brown colour as filled from new!! 2005 build!!. Its because my Dad (bless his departed socks!) would always be reluctant to add antifreeze to the cooling water because he said it would find any leak!. Nowadays engines run in antifreeze all year round.
So are you saying the brown stuff would be the original before OAT tech came along? I have the special pliers to release the hose clips but would rather replace them with worm drive ones.
BTW it is the electronic direct injection as it has push on caps to each cylinder rather than HP Metal pipes
Thanks all
Mike S

Sounds like, if it's brown, it's mostly just water by now, and is stained with rust. Definite flush required I'd say. However, there may be corrosion inside, and flushing may find trouble spots caused by it. However, just go for it, but beware some flushing solutions/preparations, are themselves corrosive by nature, so maybe if you have doubts, stick to plain water, and a good flow rate in normal and reverse directions until it runs clear.

 

[mike800966]

Oh, Crikey , now I am starting worry!
In for a penny etc, Ive bought 10 ltrs of RTU coolant Pink , based on OAT technology so I hope that should be ok. Concerned about the brown staining(sic) of the expansion tank . Have also bought a bottle of radflush, might leave that until I have I stuck the garden hose in places. Oh and repalcement worm drive clamps for the bottom hose
Thanks everyone for the advice
Mike

 

[Mike1alike]

In for a penny etc, Ive bought 10 ltrs of RTU coolant Pink , based on OAT technology so I hope that should be ok.

That should be very ok. Pink means it's G12 probably (or G12+ or G12++).

 

[mike800966]

That should be very ok. Pink means it's G12 probably (or G12+ or G12++).

Thanks, thats one worry removed! Mannol is the brand, ive been using thier engine oil for a while and seems good enough.
Mike

 

[bugsymike]

Thanks, thats one worry removed! Mannol is the brand, ive been using thier engine oil for a while and seems good enough.
Mike

I would just try a gentle back flush of the radiator to start with.
If you follow the instructions on the rad flush and only leave in for the minimum time recommended it should be OK.
Where they are a strong corrosive flush then more likely to cause damage if rad is weak.
I once saw a guy flush an old Ford Transit radiator, he left the flush in to long and the rusty core of the radiator gave up and water was leaking everywhere, you could argue the radiator was stuffed already.
I think the flushing agent was based on caustic soda, so unlikely to be in use these days.
Mannol is a well known company so their products should be fairly safe.