[Durandal]

So I've been trying to troubleshoot why my car sometimes has problems starting even though it turns over fine. I was going to check plugs, coil packs, igniter and possibly fuel filter. When I popped the protective cover off of the engine I noticed that one of the hoses running from valve cover to valve cover was cracked and showed signs of leaking a liquid substance. I have a general idea of what those hoses are for but what sort of problems would something like that cause. I am going to replace it asap.

Thx