Bought the truck with a broke pyrometer so i bought a brand new stewart warner gauge, got it all put in and it only goes up to about 600deg. with me getting after it to about 100mph, and it takes a while for it to even get to that temp. the prob is in the manifold. my last cummins would have been around 1200deg. at that speed, could the prob possibly be bad?

 

yes

 

x2 yes

 

Prob or Gauge is Bad

Luke