This sounds like a blown head gasket. Costs depend on car but a typical garage will charge about £500 upwards. If you continue to use the car in its current state, you can potentially cause engine damage.
The Therapist
July 2007
Automatic Answer
We may have found other answers which could help you.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.