Pulled in the gas station this morning to top off my coolant resivoir, (after driving 15 miles). It was almost dry, decided to pop my rad. cap and check the level. The water/rad fluid was not too low but it was full of air bubbles, like foam, beer foam. I never noticed it before because it was always too hot to pop the cap real soon. How bad is this on a scale of 1-10? Is this a sign that matters are getting worse? Should I have head gasket replaced before she blows?.Thanks......ADAMan

One more question, I am not goint to even try to attempt it myself, what does it normally cost to have it done by others 500-600 bucks?, also should I get anything else done while he is in there. Timing chain, rings, etc??. I dont want to ask the mechanic, it would be like asking a barber if I need a haircut.