Hi all, I'll try keep this as short as I can, I have had a trawl through the forum to see if my problem has been listed but so far have seen about 50 possible things it could be, so if possible would like to narrow it down. I just bought a 2004 auto xr6t and it has 120xxx kms on it, purchased from a dealer and went over it as much as I could and all seemed good. firt 2 weeks of normal driving I could not fault it, although I've never had a turbo before it seemed like it felt good, hard acceleration and I almost take of, keep it under 2000rpm and its nice smooth driving. last week drove it back from brissy to melbourne, again no issues, handled the drive with ease. since I got it have only been filling up with 98 premium fuel....until the last tank, 300k's out of melbourne the only servo I could find was a very very seedy looking liberty in the middle of nowhere....if anyone has seen deliverance, its a servo that seemed to belong there. the only fuel the had was 91 regular so I had to fill with that.....man I felt dirty while I was doing it, got back in the car and felt really guilty, and apologized to my ford. all was good but the day after I got back to melbourne, was stopped at lights after about 20min of driving then the car sturts "shuddering" at idle, around 5-600 revs. now the needle on the dash doesnt flick up and down violantly but it really does feel like the whole car is vibrationg. when I take of all goes back to normal, accelerates fine and is smooth.....when I stop starts again.... now I got to just over 1/4 tank of the crap I put in and filled with 98 to try and dilute the bad stuff, have now gone through 2 tanks of premeium and its still doing it. then today a new issue of during acceleration when it hits about 2300rpm the engine feels like its forcing itself to back down, then speed up, then back down...kind of like gearing don and back up...but revs stay the same and engine noise is normal. the temp stays good during all this as well. now been my firt turbo car can someone explain to me kind of how the engine works, from my understanding if I give it a bit when I go over 2000rpm the turbo "kicks" in and of I go, and if I drive relaxed and keep it under 2000 it just a normal I6? is that kind of correct? from some searches I've done here it looks like it coould be something to do with coils, valve springs or bung tranny......if so could someone tell me the reason these parts go and how they produce this issue? and cost of replacement, parts and labour, or if its possible to do myself? or is it as simple as crap fuel and change the fuel filter? thanks for bearing with me through this novel...will try to keep things shorter in the future. Cheers, Rick
