Yuppers, mocha flavored from Arby's would best describe the color and consistancy. Dont taste the same though. Only other reason for buildup on the bottom of the cap is if the engine has been run very much or gotten up to temperature while driving.

All your symptoms sound classic of HG failure from the exhuast to coolant or Cracked head as mentioned. Ive had both problems in the past. Get to it, stay with it and make sure you check the head before re-assembly or you will be back in there again next month....gaurenteed.

~Darin <img src="/forums/images/graemlins/baby.gif" alt="" />