Hey all,

I just started up my rebuilt 305 for the first time yesterday. It was my first rebuild, and I followed the manual to the letter. It fired up on the first try, and idled great! 55 Oil PSI. Just some minor timing adjustment needed, or so I thought. After running for about 4-5 min, the thermostat finally opened up. Next thing I know, coolant is dripping like a rainstorm. I shut the car off immediately, and climbed underneath the car to find the leak. Sure enough, it looked like coolant was dripping from where the block and heads mate on passenger side, mainly near front and back of head. I'm going to look again today when I get home, hopefully it is coming from a heater hose or freeze plug, but maybe I'm just grasping for it to be that. Checked coolant and oil, and everything looked fine. When I rebuilt it, I put new felpro head gasket and new bolts on. I am 99.9% sure that I torqued them down correctly too. Any ideas what it could be? I don't know if it's a blown head gasket, since there's no white smoke from exhaust and it runs great, no misses. Theres no coolant in oil or vice versa. I'm completely stumped and frustrated, I just want to drive my car again! It was running so nice too. Sorry for the long post, but any ideas what could cause this?? I really don't wanna excavate all the way down to the head and pull it off

 

You didn't mention using thread sealer on any of the head bolts . Did you ?

 

Yep, I used thread sealant on them. The leak doesn't look like it's coming out of the bolt holes though, it's coming out between head and block. But my engine is running fine though? At least so far it has been

 

Just got home and got car down from lift. Looked on top, and there is coolant pooled alongside the valley between the head and intake manifold. Trying to see if a leaky hose dripped down onto it, since the entire side is pooled with coolant. the intake manifold got new gaskets, maybe they were installed wrong? But the drivers side is perfectly dry. I'll post pic when I have time. I'm just glad it's not a head problem! It must have pooled up on top and drained down the sides.

 

hey all, sorry for not keeping updated. it turned out to be a cracked heater diverter valve that was dripping coolant onto the top of engine, which then pooled down the sides, making it looks like it was coming from the head. Got a new one, leak fixed. Thanks for the suggestions!