Up to 99, all the Ford single cam 4.6L V8s have plastic intake manifolds that crack and leak coolant (best case scenario). Worst case is it blows the engine through sudden loss of coolant.
Oh, that one.
The PI Vics got the recall, and the granny vics were tuned and limited in a way that made bursting that seam pretty difficult.
But for those who did, well, Ford treated them like dirt. The part is $240 wholesale, and there’s got to be five-six hours labor.
I did mine myself, so it wasn’t too bad.
Oh, and the problem wasn’t actually the plastic intake manifold itself, but the coolant crossover (molded as part of the manifold) which had a long seam in the plastic. It wouldn’t seep or leak as much as BURST.
The replacement model is a plastic intake manifold with an aluminum coolant crossover subassembly.