wehn i start my car and run it for 15 min my temperature gauge works fine.. but my speedo jumps all over... tehn 5 mins later goes down to C.. den wen i run my car 15 more mins the speedo works den doesnt den the temp does the same.. idk wat da problem is... then if i run the car for an hour the spedo works fine and so does the temp... but sometimes the speedo jumps.... HELP!! Call 911!!!LOLZ