Did you find a blown boot? It could be the intercooler, turbo, manifold gasket, loose intake horn... I'd check everything first before ordering a set of boots. Mine are original with over 200K miles on all 3 of my trucks. the 12V's both have closer to 300K miles on original boots, they aren't junk, they just won't hold 50psi all day long like a good set of silicone boots will.

 

If you decide to replace your boots this link will take you to another thread of mine where I have a link to the boots I just installed on mine. There are plenty of sorces for them this was just the best deal I found at the time. https://www.dieselbombers.com/5-9l-2...l-springs.html