TDI COOLING SYSTEM

**mox** · 6th May 2016, 07:52 PM

There are two main purposes of additives to straight water for cooling purposes. Anti corrosion, which seems far more important when aluminium is used in engine and radiator components and not just cast iron copper and brass. Then there is anti freeze. Am not sure if compounds other than ethylene glycol are commonly added to water. However, it has lower specific heat than water and reduces efficiency for transferring heat. Also, I gather it tends to leave a film of low conductivity on surfaces inside block and radiator which also reduce cooling efficiency. Seems that even in snow country in Australia where temperatures never get anywhere near as low as common winter ones in many parts of eg North America and Europe, nowhere near as much anti freeze is needed - if at all. eg Apparently 33% ethylene glycol solution protects down to minus 18 degrees Celsius. Also, seems if you don't need anti freeze, best to not use it at all. For several years. I have just used (green) Alfloc 3677 solution which is a corrosion inhibitor but not anti freeze.

**loanrangie** · 9th May 2016, 10:26 AM

To rule out or in my VC as being suspect a forum member has kindly lent me his new VC while he is OS, did a coolant change as well as i found out after a bit of searching that the coolant i used had no anti boil properties.
Fan now makes a noticeable roar when accelerating so will see how it goes this week.

**B92 8NW** · 27th May 2016, 12:28 PM

Originally Posted by loanrangie

To rule out or in my VC as being suspect a forum member has kindly lent me his new VC while he is OS, did a coolant change as well as i found out after a bit of searching that the coolant i used had no anti boil properties.
Fan now makes a noticeable roar when accelerating so will see how it goes this week.

Any joy or is it still a head off job?

**loanrangie** · 27th May 2016, 03:05 PM

Originally Posted by B92 8NW

Any joy or is it still a head off job?

It was going fine til this week, now its pushing coolant out and getting hot so yeah its head off time.
I was expecting it just not this soon, i take it your home now ?

**SSmith** · 27th May 2016, 03:38 PM

Originally Posted by loanrangie

It was going fine til this week, now its pushing coolant out and getting hot so yeah its head off time.
I was expecting it just not this soon, i take it your home now ?

Bugger!
Need a hand to get it done nice and quick?

Sent from my SM-G800F using AULRO mobile app

**loanrangie** · 27th May 2016, 04:09 PM

Originally Posted by SSmith

Bugger!
Need a hand to get it done nice and quick?

Sent from my SM-G800F using AULRO mobile app

Thanks but i'm a pro at it now, in no rush as i might be looking at a D2 on the weekend.

**SSmith** · 27th May 2016, 04:57 PM

Originally Posted by loanrangie

Thanks but i'm a pro at it now, in no rush as i might be looking at a D2 on the weekend.

Haha, you've definitely had plenty of practice

The prices D2's are going for you've gotta really love the D1 to bother fixing it.

Sent from my SM-G800F using AULRO mobile app

**loanrangie** · 27th May 2016, 06:25 PM

Originally Posted by SSmith

Haha, you've definitely had plenty of practice

The prices D2's are going for you've gotta really love the D1 to bother fixing it.

Sent from my SM-G800F using AULRO mobile app

I do love it but i really need a bit more power for towing the camper , i will fix and it will be hard to let it go - best car i have ever owned.

Sent from my GT-I9300 using AULRO mobile app

**Judo** · 28th May 2016, 09:05 AM

A bit late to the party here, but I'm quite sure coolant doesn't change the boiling point. It has anti corrosion and anti boil properties. The pressure increases the boiling point, which is ones of the reasons it's such a bad idea to remove the cap on a hot system - the coolant instantly boils as the pressure drops.

Google boiling point of water at 15psi and the answer 121*C. No coolant in the equation.

Good luck Nick.

**Tins** · 28th May 2016, 11:49 AM

Originally Posted by Judo

A bit late to the party here, but I'm quite sure coolant doesn't change the boiling point. It has anti corrosion and anti boil properties. The pressure increases the boiling point, which is ones of the reasons it's such a bad idea to remove the cap on a hot system - the coolant instantly boils as the pressure drops.

Google boiling point of water at 15psi and the answer 121*C. No coolant in the equation.

Good luck Nick.

A little cut and paste:
For every pound of pressure in a closed system, the boiling point (212?F at sea level) is increased by three degrees. For example, a 16 lb cap would increase the boiling point to 260?F (16 x 3 = 48 + 212 = 260).

Convert that to metric. 16 x 1.66 = 26.66 + 100 = 126.66 ( rough )

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