I know this is too late to help the original poster but I would have suggested you try Thermagasket. It costs about $100 but it has a money back guarantee. I used this on a 2001 Pathfinder with 130K miles that had similar symptoms. I had combustion gas in the cooling system that would blow the coolant out.They send you enough to do two tries. I followed the directions and it did not work for me. I called their Tech Support number thinking I was going to have to argue to get my money back. I talked to a real mechanic who had me take a few extra steps (compression test, take the spark plugs out of the two cylinders with lowest reading) and retry the repair. It worked like a charm. I drove that SUV for another two years and 50K miles without a single problem. I would still be driving it if my grandson hadn't flipped it on its back. He came out without a scratch, the car didn't survive.