Oily Spark Plugs and Constant Bubbles in Coolant

Hi

I have recently brought a Audi A4 cabriolet 1.8T, recently it has started to misfire and after a while constantly running on three cylinders after checking the spark plugs the threads and electrodes were soaked in oil. I have changed the plugs and have now located a dodgy coil pack.

What can be causing this?

I also have another issue, the car is not overheating on the gauge but the coolant is constantly bubbling from cold. every couple of second a few bubbles would come to the top and as it gets hotter the bubbles get worst.

What is causing this?

I am fearing its the head gasket..

Any help would be appreciated.

Thanks
Dan

OK that was my thinking.

I have ordered a sniff test kit. Fingers crossed.