FlyLow

Ok I just got my car back from th dealer again ( a new one this time). I had them look into the hesistation at about 3500k and 7500k. I've finally managed to narrow the rpm areas down to that. The rotary expert there said it had a miss and when he checked the coils two of them were bad but he replaced all four and checked the plugs and plug wires but my car still does the same thing. After a compression test a OMP test both of which passed he came out and said that the only thing tech support could come up with was that the second and third valves in the intake that open up at 3500k and 7500k were slow to open and there wasn't alot they could do about it. So I asked them if we could go out a drive a couple of the other 8's on the lot and another did the same thing. Is this BS or is there some truth to it. And if it's true will I just have to live with it? Thanks