I had a chemical test done on coolant as loosing about 1 cup full of water per week and it revealed bad head gasket.
As there are no other symptoms we are thinking maybe there were old contaminants left from the last time the head gasket had gone

A friend said he believed the carpet was damp on the foot well and said the lost water was heater matrix leak, so I put some K-seal in and as soon as I put it in my water was empty within 15 minutes and I have been topping it several times from empty since, whereas it was only loosing 1 cup a week now after using k-seal It seems I have to refill it completely every day as the bottle looks empty.
I noticed when the engine is on and hot that no water is in the header tank when you check from cold there water in the tank and this is since using k -seal ?

I've gone from only topping up about 1 cup full a week to completely refilling every day since using k-seal
any ideas ??
main thing I want to know is, why when the engine is on can no water being seen from the coolant bottle but once engine has been switched off and is cold then you can see some water in the coolant bottle, as this is after suing k -seal. why ?

 

Last edited: A moment ago

I've checked thermostat - it's working fine so it's not that

 

 

 

Regards -   the OP

I had a leak a few years ago and I used Bars Leaks.   Instant cure.   Never leaked again and I know the guy who has the car now and it still hasn't leaked after 5 years.

It needs to be bled properly, there's an air lock somewhere.

K seal often does more harm than good as it partially blocks the waterways rather than just going where it needs to.  But it won't have caused the problem you're having.

4 hours ago, TomsFocus said:

It needs to be bled properly, there's an air lock somewhere.

K seal often does more harm than good as it partially blocks the waterways rather than just going where it needs to.  But it won't have caused the problem you're having.

Indeed.  It worked magic in our old Rover 216 which suffered complete HGF (2 litres of coolant into the oil!), and after changing the oil and coolant (with K-seal) it drove for a further 6,000 miles without burning a drop of coolant. 

On the other hand, our old Volvo V40 had an issue with burning coolant and white steam when cold (plus the coolant burning smell at all times from the exhaust) and K-seal did absolutely nothing, except clog the heater core!