Ok quick story, me car has been overheated about every 2 weeks for about 2 months. It would overheat bad the guage just got hot. I replaced the thermo, cap, flushed it bla bla bla. So one morning I drive and the guage maxes out. Im 3 houses away from my friends driveway so I figued Id run it. anyway one house before my friends house the shit shuts down. I let it cool and try crankin it. nothing so I pull the spark plugs and I got a super socker 5000 comming out of my engine. Same day I change the gasket and waterpump. It hits temp and then I leave it over night. NExt day I let it hit temp and drove it around the block. runs fine for 5 min then 2 house before my friends I boost and my temp guage flys up and vacuum shows 10 psi. I drain the oil and cappacino comes out so I change the oil again. Drive it home and drive it for 3 days now and everything is fine except vacuum shows 16 psi and 13 when my interior fans are on. Im thinking I have a cracked head and it opens up when I boost. What do you guys think ?

I think you should have machined the head because you overheated it so much.

best time so far 14.3 @ 101.1mph(no traction)
www.cnnmotorsports.com

Very possible the head is warped or you have a crack in the head or block. Considering the heat you put on the old gasket before you replaced it i would take a gamble on warped head.

Our heads warp real easy in general without overheating. I pulled a stocker that came off a running parts car that had to be milled 10 thousanths and that was just a daily driver. I have seen that happen a lot with alum head motors.

Unfortunatly the bad news is you gotta go back in doc!


Terry

Yeah, heat like that will destroy a head. Pull it and check all the specs per the rebuild manual.

____________________________________________________
four nails four corners four riders and four horses

Im starting to think so to. What I dont understand is why its fine now. I somewhat boosted last night for the first time and it was solid. Im not loosing coolant or oil. I think today im gonna boost it all the way and see what happens.

yea so I took it on the parkway yesterday for almost 2 hours and everything is solid. fluids arent mixing and the temp guage stays solid. Im still afraid to boost though since the first day. My vacuum sometimes fell to about 15 also till I reved it. Im positive I have no leak. The only thing that changed vaccum wise was me replacing the hose from the intake to the valve cover. Would that cause it ?

if you pulled a spark plug and coolant pumped out as you cranked it then you have a problem. Perhaps there is a crack opening up when the heat from boost pressure or whatever. Either way driving it around babying it isnt going to solve the problem. Coolant getting intot he cylinder is not a fluke!

Terry

I cranked it hot tonight and no coolant. I think its fine now aside from the whack vacuum. Maybe thats caused by differant temperatures on differant days ?

I don't think so because your engine will pretty much always get the same temperature. That is the important part.

yea I boosted for an hour today and everything held up fine. Its also 90* outside. I also found out that my radiator fan fuse blew when my headgasket when so I wasnt getting any air at idle is might of been why my car when crazy after i boosted for the first time and idled. anyway hopefully it will hold up when i do some "testing" tonight. Thanks for everyones help, this place is awesome