big external coolant leek

[Eddiy]

I have an 03 F350 crew cab with the 6l Powerstroke. It is pouring anti-freeze down the back of the block on the passenger side. i have just had the intake off but it does not appear to be coming from anything i removed there is a slow drip from the blue hose off the egr cooler but nothing like the amount it is leeking. Wondering if maybe the head gasket has got a bad external leek? It only leeks when its hot if its cold an sitting it will leak untill it cools down. I also have no heat wondering if this has something to do with it.