Have you tried removing the one set of fans to see if temps go back to normal? That way you can rule the fans out if your temps go back to normal, otherwise you might need to re-seat your CPU block, can't think of anything else that could be causing the temp rise though to be honest.
Just give your loop a checking over to make sure nothings restricting the tubing or anything like that, you could also have an air bubble trapped in the rad so give your case a shake and a turning over.