94 with possible detonation problem
A buddy of mine has a 94 with the 4 cyl. SOHC. A manual transmission and about 130K on the odometer. In higher gear at higher speeds he has started noticing what sounds like typical detonation.The sound has become more noticable in recent months but definitely isn't detonating to the point where the engine loses serious power. When he runs 93 octane the sound goes away and comes back with 87 octane. Anyone else have the same stuff going on? Is this common for this year/engine combination? Any help would be greatly appreciated.