Join Date: Apr 2010
Ferrari Life Posts: 2,199
Sounds like there's light between the seats and the valves in #4, and that's probably because the guides are shot and allowed the valves to beat themselves up on the seats.
If this is correct then you may have just avoided some catastrophic damage to your engine, and you should be congratulated for not ignoring the symptoms (low compression). It'll be a bit dear to sort out, but nothing compared to what it might have been, had one or more of those valves gotten wedged, bent, then broken.
'99 550, Rosso Corsa / Nero, S/N:114654, Assy: 31836, Engine: 52084
High mileage, low compression, and missing on a few cylinders.....just like my cars.
Maranello Skunkworks Team Member