It sounds like you're getting a diagnosis from the dealer (maybe just a guess from a mechanic?) and then throwing parts at it based on what you're hearing. If that's what you're doing, stop. I can understand wanting to get some free advice and doing the work yourself to save the money on labor and parts. The trouble comes in when the advice is worth what you're paying for it, and you lack the diagnostic equipment and/or skills to really dig into the problem. I've been there before. You've got a tough problem here, you're without the use of the vehicle, and you've spent money that you won't get back trying to fix it yourself. Enough is enough. Let a pro diagnose and repair it. It may be expensive, but it will be cheaper in the long run and they'll own the responsibility for making it right if they misdiagnose it. Make sure you don't just take it anywhere; find a shop with an excellent reputation. That might not necessarily be the dealer.
