Ethylene Glycol BLUE antifreeze coolant
 

Shops seem to want us to buy pink stuff at inflated price.
Does it mix with the old ? I suspect not.
Where to get the blue stuff at sensible dosh ? wont be halfrauds.
Or is there a better replacement that will mix ? Never get all the old out even with a thorough flush.

Why must you have a blue one? Colour is pretty meaningless and you still need to check that the coolant technology (OAT, phosphate, silicate, whether) is compatible with whatever you've currently got in there (or do a full flush and change).

I got 1L of concentrate from a Volvo dealer for top-ups. Was about £6.50.

The traditional blue antifreeze is still available from good Motor Factors and from outlets like Eurocarparts etc. It can cost as little as £2 / ltr if bought in large drums. I recently filled the cooling system of a large diesel locomotive with anti freeze mix and, as it needed 80 gallons of coolant, price became a serious consideration!
The reason it is going out of favour is that Ethylene Glycol is very toxic and alternatives such as Polypropylene Glycol are being used instead.
I have found that Prestone is a very good alternative as it is universal and can be mixed with anything, so it is what I tend to use in my cars.
I get it from Costco, but it should be available from Motor Factors as well.

Older engine and oat will eat your seals. Defiantly cannot use it in the 1994 landrover.

Paul.

what is prestone made of ? not taking chances when ethyl is cheaper

Poundland shops sell ready mixed at[surprisingly]£1/L

very cheapy. Whats the concentration ? does the bottle even say ?

According to their CoSHH sheet, it is:

Ethylene Glycol 75-95%
2-Ethyl Hexanoic Acid, Sodium Salt 1-5%
Neodecanoic Acid, Sodium Salt 1-5%
Diethylene Glycol 0-5%

They claim it is suitable for any car or truck engine

https://www.holtsauto.com/prestone/p...eze-ready-use/

The pink stuff should be avoided in any car from 2000 or older. As someone else pointed out, the pink/red OAT stuff will eat the gaskets and seals as they're not acid resistant - OAT is Organic Acid Technology.

For the same reason, any engine with cast iron components (all red blocks have a cast iron block for example) shouldn't use it as the acid will rot the block. The OAT coolant was developed in the late 90s by the Japanese for all-aluminium engines as the ethylene glycol was causing (comparatively minor) corrosion to the aluminium blocks over time. However, nothing to what OAT will do in a cast iron block.

The two (OAT and EG) antifreezes should never be mixed as the ethylene glycol causes silicates present in the OAT to precipitate out, forming a gel which blocks waterways in the block, heater matrix, radiator and so on and can't be flushed out. In other words, mix the two and you have a scrap engine.

Also, when changing the antifreeze, don't buy the "Ready to Use" pre-mixed "Antifreeze & Summer Coolant". For starters, you don't know what the concentration is. Second, it's good practice to back-flush the system when you change the antifreeze.

The method i use and has never let me down, is to add a coolant flushing agent (this is optional but very effective), run the engine up to temperature to get the flushing agent circulated.

Let it cool and remove the thermostat, refit the 'stat housing so the system is once again complete (except the 'stat) and remove the top hose from the radiator. Insert the garden hose into the top hose and turn on. On cars without A/C, set the heater temperature to maximum - on A/C cars, the lack of vacuum (engine not running) defaults the heater valve to hot.

Leave the hose running for at least half an hour and check to see if it's clear. If so, let it run another 20-30 minutes. This will ensure that all the flushing agent and old antifreeze is out.

Now your system is full of clean water - there may be a dribble of old antifreeze somewhere but it won't be much, if any.

Disconnect the bottom hose at the radiator end to drain out. This won't drain the entire system but will release enough space for the new antifreeze (same type as the previous) to be added. Once drained, refit the bottom hose. Refit the 'stat in the 'stat housing.

If your system is a total of 10L and you need a concentration of 50%, the next bit is easy as the likes of ECP etc sell ethylene glycol in 5L tubs. Using a 5L tub of concentrated antifreeze, add the entire contents to the cooling system, topping up with water.

Run the engine up to temperature and allow to cool, preferably overnight. Top up before use the next day with water if needed. You already have enough antifreeze for the 50% concentration so water is all that is needed.
Re-check the next day on the level, topping up if needed but probably won't be needed.

Chances are the newer OAT stuff is also available in 5L tubs so the same could apply if the cooling system is 10L total. I've never checked, i've never needed to.

I've used this method for decades without a problem. I previously had problems just draining the coolant simply by removing the bottom hose, it didn't empty the system so i ended up with the system half full of old antifreeze/water when i added the new stuff. That's why i developed this method and used it. ;) :D

whats wrong with there being a bit of old coolant in there ? assuming its not as good as it was, just do the sums as though its water. Or; simply pour in the whole 5-litre bottle and add water as required. Not worth keeping a pint of antifreexe in the shed, might as well be in the engine