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I need to top up my Mk3 coolant/antifreeze and I understand that this can only be with Volkswagens own coolant/antifreeze.

Is this the case or is another suppliers acceptable? What is the cost of the Volkswagen coolant from a dealer?

Thanks

If it's the blue stuff, then get some G11 type coolant from GSF.

The dealers only sell the new purple type of anti freeze/coolant which is supposed to be compatible with both the older and newer types.

Would it be worth me replacing my coolant completely? It hasn't been done since new by the looks of it, and may now just be water with a very weak anti-freeze. I am assuming you are reffering to the stuff in the expansion tank behind the washer tank?

Thanks.

Karl.

Karl_CLCoupe wrote:Would it be worth me replacing my coolant completely? It hasn't been done since new by the looks of it, and may now just be water with a very weak anti-freeze. I am assuming you are reffering to the stuff in the expansion tank behind the washer tank?

Thanks.

Karl.

It would indeed - antifreeze is similar to brake fluid (well OK its nothing like brake fluid but bear with me here) It's effectiveness is reduced with age

Brake fluid is hydroscopic and absorbs water over time - it's a bit late to think of changing it when at the bottom of a long hill and your middle pedal is down on the floor and the car is still gathering speed......

You should change it ever year or at worst every two years

few words of advice

- use the highest DOT level posible (with the exception of DOT 5 which is synthetic and gives a really spongy pedal - it doesn't damage the paintwork being synthetic but the subsequent accidents will do that!!!)

- use an easibleed system to change it - don't do it by pumping the pedal and opening and shutting the bleed nipples cos you can invert the seals in the master cylinder

Antifreeze loses its potency over time - it's a bit late to think of changing it when your core plugs are all popped out and sitting under the car in the middle of winter

A change of an antifreeze also helps to pull all the rubbish out of the block that shags the pump bearings and blocks the heater matrix up

Few words of advice

- don't use the long life stuff - it's really bad news - lots of litigation flying round in the US

- Pick the right antifreeze ie if you have an alloy head on a cast iron block use the correct fluid

opinion (ated) git - yes

is it difficult to change, thats the thing

following the brake fluid debacle i just experienced (final cost - £110 at the garage, plus god knows how much else trying it myself), i'm having a go at slightly more simple simon servicing thats harder to balls - just plugs and (engine&gearbox) oil... coolant be worth a shot as well, or is it something thats likely to leave a guy crying on the driveway and having to contemplate towing the car to the garage again?

It's pretty easy to drain and refill the cooling system.

Make sure the car is warm and have it on a flat surface. After you have turned the engine off, get a pan under the bottom rad hose to catch the coolant. Get some grips on the hose clip and slide it back, then the bottom hose will need some twisting to get it loose, then pull it off so all the coolant goes into the pan.

Be careful not to get hot coolant on you (wear gloves).

Then take the top rad hose off so you can put a hose pipe in, to flush it out with water. Make sure water flows out clean at the other end. You can flush the other part by inserting the hose into the header tank too.

When your happy with that, put all hoses etc back in place. Get your mixed coolant and slowly fill the header tank up, don't pour it in quick as this can encourage air locks. When it looks full, start the engine with the heater on the hot position inside, blowing air. Don't let it get warm without the header tank cap on. The level might drop a bit, so keep topping it up and open the heater bleed screw to let any bubbles out, this might take a while.

Wheres the bleed screw located? I was looking at flushing the coolant system out at some point before I can drive the thing, as well as give it a good (basic) engine service. Would be handy to know for nearer the time.

Thanks.

Karl.

The bleed screw is located on the top of the heater matrix.

When I flushed out my cooling system, I did what hardhitter said, but that was only to flush the rad out. I then removed the thermostat housing and directed a clean jet of water into the expansion tank until it ran clear out where the thermostat is located. This flushed the old coolant out of the engine aswell, so that the whole system is completely refreshed.

It really is a very easy task to do. The hardest part is making sure it is air free. To do this, I unscrewed the header tank cap, squeezed all of the coolant pipes to get the big locks out, then used the bleed screw until bubble free coolant flows out of it.


EDIT: Sorry, I just read his post again, and he says to do it when the engine is warm. That way, the thermostat will be open and therefore you will not have to remove the thermostat itself. Either way will work just fine.