Hey Bimmer Humans,
So...I enjoyed an aggressive week of driving the 4.4i ('03 4.4i 136,000miles) in manual shift mode, simulating F1 apex lines and entry speeds.
3 weeks later, and after a full tank of 87 octane gas (specs call for 93 only), a ticking from the engine developed.
After being on the second fillup of premium 97, additives such as engine lifter lubricant and sea foam as well as slick 50, the ticking has not ceased.
An executive global engineer for Dow chemical shared that any change to a chemical process takes a minimum of 3 process changes when dealing with liquid combustion (ie 3 tanks of gas) to counter any degradation of performance due to incorrect spec'd fluid dynamics). I have one more tank to try to meet this requirement.
If it is not the gas, then it is probably the lifters. Any experience with this issue? Any input greatly appreciated in advance.