spark knock/valves clattering

Any sugestions on how to fix this? I have a 2005 Mustang GT stick shift with only 10,000 - problem started at around 7,000 - slight valve clattering/knocking on acceleration going from 3rd to 4th, sometimes in lower gears, but usually in 4th. I've taken it to the dealership a total of 5 times, starting back in August with the last visit two weeks ago (mid-October). They first tried to tell me it was gear noise, then they said it had to do with the fuel system- they changed out (or said they did) the fuel pump and fuel filter, even though the car only had about 8.000 miles. They've finally acknowledged that it's spark knock and has to do with the timing (what I had thought all along), but said that the 05 GT has a self-adjusting timing and they didn't know how to adjust it otherwise - i.e. they couldn't fix it. Then, the guy went on to tell me that the noise "wasn't hurting a thing" but that they would work on finding a solution - that was during my fifth visit to the dealership (each time, leaving my car for no less than 3-4 days). I've called back twice since mid-October and have gotten "still know nothing, but working on it"  - even though they have not once called me. I feel as though I've just been screwed around and that they have no intentions on fixing the problem, especially since the service manager told me he felt that "it wasn't hurting a thing." I mean, if you bought a brand new car and it had a crack in the windshield, even thought it "wasn't hurting a thing" you would still expect it to be fixed, right! I told the guy, I didn't care what he had to do, even if he had to replace the engine, as long as it was fixed - of course, he commented that they wouldn't do that and he didn't know if they would be able to fix it or not. Wondered if anyone could tell me how to adjust the timing manually or what steps I should take (going over the service manager at the dealership) to get this taken care of  

I also has this problem with a '98.  After several trips to the dealer where I bought it, I was told the same thing, "Yes, we can hear it and No, we can't seem to tune it out of it, but it won't hurt anything." (I have never had anyone with any knowledge of engines tell me that spark knock will not hurt the engine).  I finally took it to another Ford dealer and they we able to isolate the faulty part and cure the problem.  (Can't remember what the part was)  Bottom line, don't give up, it can be fixed.  

Well it's like this the Dealership is suppose to have people that are trained and certified to work on their vehicles, and they are to know everything inside and out before they are certified, So what it sounds like to me is they don't have anyone there that is allowed to work on your mustang, Because if they were certified then they would have been able to fix the problem the first time you took it in. I would report that dealership if I was you and take the Mustang to another dealership for now on.  

always go to the General Manager with a problem like that and if that doesn't work tell them that you want to talk to the owner of the bussiness, then if that doesn't work report the dealership to the main Manufactoring place on top of to the BBB And tell them that they will be hearing from your lawyer.And read your warranty and see if the problem is covered under warranty, because if it is and they can't fix it then they have to replace what ever it is with a brand new one whether it's a new motor or transmission they have to replace it if they can't fix it if it's under warranty, that's what the warranty is for.