Activa & V6 coolant changes.

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

User avatar
chinkostu
Posts: 1180
Joined: 24 Sep 2014, 09:41
Location: cheshire
My Cars: N Xantia 1.9TD SX
03 Fiesta 1.4 Zetec
x 30

Re: Activa & V6 coolant changes.

Post by chinkostu »

My TD is running old school stuff, I wasn't sure what was in there before the matrix change so ran it a fair few times with water then dumped it out and when it started coming out a cleaner colour I filled and bled. No issues since, and XUD's are finicky about coolant duration if i remember right.

Is it worth spending more than what a new expansion tank and coolant is worth on something that we haven't really tested? It could be gods gift but at the price its probably cheaper to pop all the hoses off, replace anything, flush it and refill with OAT!
Stu

Cars
1995 Xantia 1.9TD SX in (faded) Red
2003 Fiesta 1.4 Zetec in GREEEEEEEN
2001 206 1.9 LX
2001 Saxo VTR
1999 Saxo 1.1 East coast
1999 Punto :oops:
1996 306 1.8 XN Auto :?
1996 Fiesta 1.3 #-o
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: Activa & V6 coolant changes.

Post by Mandrake »

Deanxm wrote:i would love to use it on the V6 engine when it goes in the XM but there is one issue, cost! i think the xm takes something like 10ltrs which is a lot when your paying £20 a litre for the prep fluid and the same again for the coolant that adds up to n astonishing amount of money!
£160 for the 8 litres of coolant required in the V6 for a car that is only worth 3x that ? :rofl2:

Lets not forget that unless it has some magic pixie dust in it, it too much be changed every few years to renew the corrosion inhibitors. Just because it isn't water doesn't mean there won't be electrolytic corrosion due to dissimilar metals in the coolant system and just non water related corrosion in general. Also if you ever have a leak like a radiator that needs to be replaced you're draining £160 of coolant down the drain...

A complete non-starter with an old car - traditional coolant is extremely cheap and it really isn't that much of a burden to change it every 2 or 4 years. I will admit to being a bit slack on coolant changes on my cars over the years but after the thermostat corrosion issue I just had I will be keeping on top of it in future!

On the V6 coolant drain, change and bleed is actually exceptionally quick and easy once you know where the bleed points are - much easier than many other cars and you don't even need a header tank.

For goodness sake if there is a coolant leak or pressure leak just get it fixed. ;)
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
User avatar
CitroJim
A very naughty boy
Posts: 49531
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6160
Contact:

Re: Activa & V6 coolant changes.

Post by CitroJim »

Deanxm wrote:Dont be so cynical, ive just checked and its mostly Aqua so not a drop of water in site lol
The word 'aqua' is so often used to disguise water, just as fructose is used to disguise sugar in lots of food!
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
User avatar
Paul-R
Donor 2023
Posts: 6916
Joined: 07 May 2009, 16:24
Location: Wirral, NW England; Vaucluse 84, France
Lexia Available: Yes
My Cars: 2015 1.6 Blue HDi 120 Peugeot 308 Active SW
2013 2.0 HDi 163 C5 Exclusive Tourer
2003 2.0 HDi 110 C5 Exclusive Estate (Gone)
2001 2.0 HDi 90 Xsara Estate (Gone)
x 1369

Re: Activa & V6 coolant changes.

Post by Paul-R »

From looking around it appears to be another glycol. Not ethylene glycol, as used in ordinary anti-freeze mixtures (both silicate and OAT) but propylene glycol.

Ethylene glycol is poisonous and propylene glycol isn't but this is not the main reason for using it. Propylene glycol has a wider range between freezing and boiling point and, I think more importantly, a lower freezing point (-12.9C/197.3C against -59C/188.2C) as -12.9C is easily achievable in many parts of the world.

Both glycols are sweet to the taste but PG is so non-poisonous that it is used in the food industry as a sweetener. It's also used in solar heating panels where, if a leak were to occur between the circulating liquid and the household hot water, it would not end up poisoning the family!
As I get older I think a lot about the hereafter - I go into a room and then wonder what I'm here after.

Inside every old person is a young person wondering what the hell happened.

"Trying is the first step towards failure" ~ Homer J Simpson​
User avatar
CitroJim
A very naughty boy
Posts: 49531
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6160
Contact:

Re: Activa & V6 coolant changes.

Post by CitroJim »

Paul-R wrote:Both glycols are sweet to the taste but PG is so non-poisonous that it is used in the food industry as a sweetener.
I always wondered what PG was doing in some foods... Now I know :) Thanks Paul!
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
User avatar
Mandrake
Posts: 8615
Joined: 10 Apr 2005, 17:23
Location: North Lanarkshire, UK
My Cars:
x 664

Re: Activa & V6 coolant changes.

Post by Mandrake »

Paul-R wrote:From looking around it appears to be another glycol. Not ethylene glycol, as used in ordinary anti-freeze mixtures (both silicate and OAT) but propylene glycol.

Ethylene glycol is poisonous and propylene glycol isn't but this is not the main reason for using it. Propylene glycol has a wider range between freezing and boiling point and, I think more importantly, a lower freezing point (-12.9C/197.3C against -59C/188.2C) as -12.9C is easily achievable in many parts of the world.
Ok so lets assume for a moment that these "waterless" coolants are just a 100% mix of Propylene Glycol. This might look good on paper for freezing and boiling points but as a "coolant" it would perform poorly in actual heat transfer due to the specific heat of Propylene Glycol being far lower than water. Good old fashioned plain water has a very high specific heat capacity as liquids go, and is much higher than either Ethylene Glycol or Propylene Glycol. So purely from the point of view of heat transfer water is the best.

Obviously corrosion and poor boiling and freezing points make pure water a non-option so its properties are modified by mixing it with something else.

The following article (which I posted in another thread not long ago) gives a nice summary of the properties of water, traditional ethylene glycol and the mixes in between in relation to boiling point, freezing point and specific heat capacity:

https://hellafunctional.com/?p=629

The important thing to note is that in the case of Ethylene Glycol a 100% mix is actually a really poor coolant in two ways - 1) The freezing point of pure ethylene glycol is only about -12 degrees, whereas a 65% mix freezes at -58 degrees C, and a 50% mix freezes at -38 degrees C. So pure Ethylene glycol is not sufficiently low in freezing point for cold climates. (A 100% mix will boil at 190 degrees C though, which is good) But more importantly it only has a specific heat capacity of about 65% of water. This compares to 88% for 50% mix and 95% for a 25% mix used in warm climates. This means that the efficiency of the entire cooling system drops as the coolant has a greatly reduced heat carrying capacity.

For the same radiator and pump flow rates it won't be able to transfer heat to the radiator as effectively and could result in overheating when pushing the engine hard depending on how much safety margin is designed into the cooling system. This is one reason why hot climates without a risk of freezing tend to use lower mixtures of antifreeze like 25% - it actually works better as a heat transfer medium. (I never used a 50% mix in northern NZ, always about 25%)

So pure Ethylene Glycol will "work", but performs a lot worse in all respects other than boiling temperature than a mix with water.

So how about Propylene Glycol ? As Paul said above, a 100% mix will freeze at about -59 degrees C - about the same as the best mix of water and Ethylene Glycol, and it will boil at 188 degrees, far in excess of a normal water and ethylene glycol mix. So boiling and freezing point look great on paper. But what is the specific heat capacity ?

http://dowac.custhelp.com/app/answers/d ... eat-values

From the graph we can see that depending on temperature the specific heat capacity is only 60-65% of water, compared to the 65-75% of water for pure ethylene glycol. So for heat transfer ability it is worse than pure Ethylene Glycol, let alone an Ethylene Glycol+Water mix. So its actually a pretty poor heat transfer medium that could result in a hard worked engine overheating even without boiling or pressurising the system.

You could probably create a more favourable mix of Propylene Glycol + Water that improves specific heat capacity but then it's not a "waterless" coolant is it! :lol:

From the article itself:
As would be expected, the addition of water to a glycol increases the specific heat. This is important whenever glycol solutions are considered for use as heat transfer media. A liquid with a high specific heat will do more work per unit weight than one with a low specific heat if all other factors are equal.
So if this waterless coolant is just 100% Propylene Glycol and a few anti corrosion additives for £20 a litre then colour me extremely unimpressed! :?

It's either something else, or it just isn't very good!
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
User avatar
Paul-R
Donor 2023
Posts: 6916
Joined: 07 May 2009, 16:24
Location: Wirral, NW England; Vaucluse 84, France
Lexia Available: Yes
My Cars: 2015 1.6 Blue HDi 120 Peugeot 308 Active SW
2013 2.0 HDi 163 C5 Exclusive Tourer
2003 2.0 HDi 110 C5 Exclusive Estate (Gone)
2001 2.0 HDi 90 Xsara Estate (Gone)
x 1369

Re: Activa & V6 coolant changes.

Post by Paul-R »

Thanks for that Simon, I must have missed those links in the past. We've had a discussion about coolants here before although we didn't go into waterless coolants IIRC. I remember making a comment about making water wetter to improve the heat transfer at the boundary between the coolant and the engine.

I must confess that, even allowing for the cost aspect, I don't really see the reason for waterless coolant. The main thing that I picked up is that it allows you to run the cooling system at just above atmospheric pressure which would mean less strain on pressure sensitive areas such as welded seams and hoses. The rest seems to be hype and bragging points at the bar.

Or have I missed something?
As I get older I think a lot about the hereafter - I go into a room and then wonder what I'm here after.

Inside every old person is a young person wondering what the hell happened.

"Trying is the first step towards failure" ~ Homer J Simpson​
User avatar
white exec
Moderating Team
Posts: 7445
Joined: 21 Dec 2015, 12:46
Location: Sayalonga, Malaga, Spain
My Cars: 1996 XM 2.5TD Exclusive hatch RHD
1992 BX19D Millesime hatch LHD
previously 1989 BX19RD, 1998 ZX 1.9D auto, 2001 Xantia 1.8i auto
and lots of Rovers before that: 1935 Ten, 1947 Sixteen, 1960 P5 3-litre, 1966 P6 2000, 1972 P6 2000TC, and 1975 P6B 3500S
x 1752

Re: Activa & V6 coolant changes.

Post by white exec »

Precisely.
Cynical? Moi?
I didn't get where I am today by . . . :roll:
Chris
User avatar
CitroJim
A very naughty boy
Posts: 49531
Joined: 30 Apr 2005, 23:33
Location: Paggers
My Cars: Bluebell the AX, Polly the C3 Picasso, Pix the Nissan Pixo, Propel the duathlon bike, TCR Pro the road bike and Fuji the TT bike...
x 6160
Contact:

Re: Activa & V6 coolant changes.

Post by CitroJim »

Simon, most interesting... Thanks from me too...
Jim

Runner, cyclist, time triallist, duathlete, Citroen AX fan and the CCC Citroenian 'From A to Z' Columnist...
User avatar
Stickyfinger
(Donor 2016)
Posts: 10411
Joined: 28 Mar 2013, 21:05
Location: Somset my lovleee
My Cars: Xantia V6 ACTIVA 3ltr 24v Manual p1
Xm 2.1TD Ph2 Exclusive
AX, little Daffodil
SAXO White Mk1. Sally
x 1280
Contact:

Re: Activa & V6 coolant changes.

Post by Stickyfinger »

PH levels and oxygenated water, the keys to controlling any corrosion of metals in a sealed/pumped water mix. Good coolant additives control this, get this correct and you control electrophilic/electrolysis corrosion as well as oxidisation of metals.

Freeze protection of water is the easy part IMO.
Alasdair
Activa, the Moose Rider
3x C5x7 Steering racks and counting
Deanxm
Posts: 3327
Joined: 18 Dec 2008, 17:57
Location: Isle of wight
My Cars: Citroen XM
x 87

Re: Activa & V6 coolant changes.

Post by Deanxm »

Mandrake wrote: £160 for the 8 litres of coolant required in the V6 for a car that is only worth 3x that ? :rofl2:
Not sure what XM prices you are looking at but a good RHD V6 is unfortunately not £500 even if you could find one, I get your point as they are not 10k either but you could apply that mentality when it comes time to service the car or fit tyres, my thinking was that parts are all pretty much unobtanium, heater hoses, water pumps, heads, header tanks etc etc
If you can do something to preserve these then all the better, if it was the same cost as a standard coolant or maybe 20% more I would be running it now without hesitation but as others have said using the correct flavour of Aqua with the right coolant additive there will be no issues at all with corrosion and that is what I will do until I can find waterless coolant at OAT price levels, which will probably be never.

I do believe the waterless is beneficial over normal coolant mixes but only if priced the same.

D
XM Prestige PRV6 92
Talbot Express Autotrail Chinook 89
Mitsubishi L200 Trojan 14
Xantia Activa 95, sold (missed)

Service Citroen is awesome, it shows me pictures of all the parts i used to be able to buy............
mickeymoon

Re: Activa & V6 coolant changes.

Post by mickeymoon »

I think Simon was referring to his own V6 Xantia being worth 3 times the £160...

Sent from my SM-G925F using Tapatalk
User avatar
Paul-R
Donor 2023
Posts: 6916
Joined: 07 May 2009, 16:24
Location: Wirral, NW England; Vaucluse 84, France
Lexia Available: Yes
My Cars: 2015 1.6 Blue HDi 120 Peugeot 308 Active SW
2013 2.0 HDi 163 C5 Exclusive Tourer
2003 2.0 HDi 110 C5 Exclusive Estate (Gone)
2001 2.0 HDi 90 Xsara Estate (Gone)
x 1369

Re: Activa & V6 coolant changes.

Post by Paul-R »

Deanxm wrote:I do believe the waterless is beneficial over normal coolant mixes but only if priced the same.
Leaving out the cost, why did you think the waterless coolant is better?
As I get older I think a lot about the hereafter - I go into a room and then wonder what I'm here after.

Inside every old person is a young person wondering what the hell happened.

"Trying is the first step towards failure" ~ Homer J Simpson​
Deanxm
Posts: 3327
Joined: 18 Dec 2008, 17:57
Location: Isle of wight
My Cars: Citroen XM
x 87

Re: Activa & V6 coolant changes.

Post by Deanxm »

mickeymoon wrote:I think Simon was referring to his own V6 Xantia being worth 3 times the £160...

Sent from my SM-G925F using Tapatalk
Even so so vehicle value has nothing to do with maintenance cost, i would say but fair enough.

Why would i have waterless? because i can stick it in and it will do the job for 20 years, i can run the system as open vented so no more popping expansion tanks and stressing hoses and seals, and if a the blurb is to be believed when im done i can tip it down the drain rather than run it down the tip for disposal. I wouldnt leave out the cost in this decision as if they were the same price i would say those benifits are worth it, as prices stand i dont think they are.

D
XM Prestige PRV6 92
Talbot Express Autotrail Chinook 89
Mitsubishi L200 Trojan 14
Xantia Activa 95, sold (missed)

Service Citroen is awesome, it shows me pictures of all the parts i used to be able to buy............
User avatar
white exec
Moderating Team
Posts: 7445
Joined: 21 Dec 2015, 12:46
Location: Sayalonga, Malaga, Spain
My Cars: 1996 XM 2.5TD Exclusive hatch RHD
1992 BX19D Millesime hatch LHD
previously 1989 BX19RD, 1998 ZX 1.9D auto, 2001 Xantia 1.8i auto
and lots of Rovers before that: 1935 Ten, 1947 Sixteen, 1960 P5 3-litre, 1966 P6 2000, 1972 P6 2000TC, and 1975 P6B 3500S
x 1752

Re: Activa & V6 coolant changes.

Post by white exec »

Are we absolutely sure about all those claims - no water content, indefinite life, greatly elevated boiling point, corrosion protection, no disposal issues...?

Dean, could you post a link to the product site, please?
Chris
Post Reply