i have a 99 gt a little while back i wrote about a problem with my car, it would leak coolant out of the overflow cap after 10 minutes or so of driving, then the water pump went out. replaced the cap and pump, stil leaks water out of the cap. so we flush/burp the system and get a misfire on cylinder 5 while the car is idling. remove the coil and found some water in there, blew it out with compressed air and now its all good. but still leaks out of the rad cap. changed thermostat, bled air out of system again, still leaky. i didnt drive it for a few days after that, then yesterday i take it to a friends house, maybe 15 minutes away and the bitch leaks a bunch of coolant out again, i get there, add some water, and we drive around a little bit. it all seams good. no leaks after like 30 mins. then check engine light comes on, read codes and it says misfire on cyl 5 and 7, wtf? why? i was thinking maybe headgasket, but the car does not overheat, temp needle never goes past straight up on the guage and it ran fine (aside from coolant leakage out of the cap) for a couple weeks before it started misfiring again, and the coolant doesnt seam to be disappearing anywhere when its not leaking out of the overflow. has anyone heard of such a thing? the car has 73k miles on it. could this be a sign of a cracked manifold everyone is always talking about, i thought 99+ intakes where corrected?? i bought the car knowing it had a few problems but this is getting rediculous.