Cooling system question

[AutoAndy]

I need some advice as the search system is down again, and my wife has "filed" my Steve Heath bible "somewhere" when she cleaned out the study!


I have just put on my shiny st.st. water pipes, now have the following questions;

1) I used the standard non-cat lower steel pipe as my car has been de-catted. But when I took mine off, the old rubber connector hose to the water pump had insulation over the top of it. Is this just due to the heat from the cats originally fitted, or will I need some insulation now (approx 3/4 to 1" away from the de-cat pipe)?

2) What is the water to anti-freez mix that is currently accepted as being best for a 2.9 V6 engine?

3) Lastly, can you clarify the filling process that best avoids air traps etc?

Cheers Andy

[phillpot]

1. Just a guess but as you say probably to do with the cats, not needed now?

2. 33% anti freeze (1 part to 2 parts water)

3. Fill with the bleed screw on rad open, close when water comes out, carry on filling till swirl pot full. set heater to "hot" and take for a good blast.
let it cool then check level and for leaks, top up if required, take for another blast (you may have to do this all weekend )

[AutoAndy]

Thanks Mike

... I want the cooling to work when speeding to the border on the Spa trip as I out run the breathalyser police

[orange_dodo]

Andy my car never had a cat and doesn't have any insulation on the pipes so I think you'll be safe without.

2. I've always mixed it 50:50 but it makes sense to use a lower ratio as you lose low temperature protection but gain cooling efficiency. Here is a random graph to look at...



30% should be good for -10C

3. When filling up ensure you turn the car upside-down and onto it side regularly, that will let the air escape.

[King Fisher]

Best way to bleed the system is:

1. Drain system.
2. Get a low trolley jack. Jack the car up so that the air bleed screw is at a similar level to the swirl pot (air rises to the top of a system, so if you get the bleed screw high enough, it will be forced out of the system).
3. Begin filling through the swirl pot until water rushes out of the bleed screw on the radiator.
4. Tighten bleed screw, fill swirl pot to just under the top hose, tighten cap.

That'll do it, Nick's always done it this way and it works a treat!

[AutoAndy]

Thanks, that sounds like a useful variant on the theme - I will try it

[AutoAndy]

...tried it...but doesn't seem to have a radiator bleed screw and so the air pocket doesn't allow any flow into the rad.

Any ideas, or is it hidden in the boot or somewhere daft like that?

[Griffinr]

Surprised there is no bleed screw, next option is to slacken the top hose at the rad and ease it off enough for the air to get out as you fill it. When its full re-fix the hose and run the engine to push any remaining air round the system into the swirl pot. Then just check and top up.

Rob.

[junglieD]

AutoAndy said:

...tried it...but doesn't seem to have a radiator bleed screw and so the air pocket doesn't allow any flow into the rad.

Any ideas, or is it hidden in the boot or somewhere daft like that?

On my S2 the radiator bleed tap is at the bottom of the rad (drivers side). Think that means my rad is mounted upside down. It doesn't seem to affect cooling performance just means that bleeding the air is a slower process as you just allow it to work its way out of the system.