What do you think of this? Ive had a deep knock for a couple months, tried 2 tanks of cleaner/been running 2smoke oil. Took it to one guy, said its not injector. he went on vaca and said he could tear into it in a week. My gut told me try another guy. Went to my Father in laws mech. He said there is a TSB on a knock from the area of #8 cylinder. He said the knock sensor is not throwing a code, nore is anything else. They stethescoped it and said it doesnt sound like wrist pin or crank journal. The TSB talks about LB7s being prone to this, and no fix suggested. Not that Im looking to spend big money, but this knock is embarrassing. What ya think? Thanks,Frank

Nobody ever hear of this?