问：失去60 mph的电源

我的Chevy Express 1500在加速期间失去了电源，并以60 mph的速度流行和pings。它有大约82K英里。它在引擎盖下有板球声音，然后将其带到当地的维修店。风扇有一个松散的螺钉，当风扇转动时撞到了风扇，这引起了噪音。风扇离合器被替换为更好的操作风扇。我也要求他们更换蛇形皮带。2天后，当我加速至60-65 mph时，我再次注意到动力损失。发动机溅射发出弹出声音。它并非一直在发生，但大约有60％的时间。我尝试了一次填充物上的高辛烷值，这似乎解决了问题，但是在下一个填充物上，我回到了便宜的汽油，问题立即恢复了。 The repair shop told me that a high mileage tune-up should solve my problem. Do you think the first repair this the repair shop did for me created the second problem? Or is it a coincidence that I started having power issues just after his first repair? Another repair shop suggested I use a can of BG 44K fuel additive.