I have an 04 gt, about 160,000 km on it. 2 months ago I had it completely tuned up; new plugs, wires, fuel filter, cleaned throttle body etc. I had this done because it was starting to "ping" while going up hills. I purchased it at 125K, assumed the previous owner had done maintenance on it (since it's been driving really well up until a few months ago), but apparently not; mechanic broke one of the plugs while trying to remove it.
Anyway, the ping has reduced somewhat, but is still there; I've run 2 bottles of lucas fuel system treatment through it, and it really went nuts with the pinging while driving with the last batch of the lucas in my tank (much worse with the lucas in the tank than it was with the previous tank of gas). I'm on my first or second tank without the cleaner in it, but going up hills I've noticed it becoming worse and worse; not so much pinging now, but a surging of some sort; the surging will be in a range of about 500 rpms. It's definitely not normal, I've driven the car for a few years and know what to expect from it. Once I push the pedal a little further, then it will drop down a gear and the surging is much less noticeable at the higher rpms, but I still think it is there faintly. Normally going up these hills it's not necessary to make it drop down a gear; I used to drive about 110, 120 km/h up them (it's on a freeway), rpms are usually around 2000 - 2100 or so, used to drive up them with ease. I only notice the surging as described above; idles like normal, and can't notice anything wrong with hard acceleration either (not that I do that often).
Anybody have any ideas, stuff I can ask a mechanic to look at? (I can't do much myself, not much of a car guy). Thanks in advance...
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Originally Posted by BillBoost37
