Very tight exhaust valve lash

Hey y'all,

Just measured my valve clearances.

Exhaust valve clearances are VERY tight, all of them around 0.003 to 0.005 in. They're supposed to be 0.010 to 0.014 in.

Intake valve clearances are only slightly out of range. Around 0.005 to 0.006 in.

I ordered shim and bucket tools to take out the shims and measure them... they're in the mail.

Questions:

1. Could the tight valves be from a cracked header? I just replaced the cracked cast iron header with a newer header. I should note I bought the truck only four months ago ('98 2.7 4x4 185k)

2. Also, could the valves be burnt from such a tight clearance?

Thanks!

 

as to the valve clearance issue being caused by the cracked exhaust, no and yes, eventually the valves will burn. The .003 you measured was at optimal conditions... image how hot the exhaust valves get and expand when you are running the motor hard like pulling a long hill.