Old timer told me to stop using impact guns on injector hold-down bolts

I was at a shop in Tulsa last month and this retired guy watched me swap injectors on a 6.7 Powerstroke. He said I was going to crack a bore if I kept zapping those bolts with my impact. I argued back at first but then tried his way using a torque wrench set to 28 ft-lbs. The truck came back quieter and no more stiction issues. Has anyone else made that switch and seen better reliability?

2 comments

2 Comments

williams9019d ago

My buddy runs a diesel shop in Oklahoma and he swore by impacts until he cracked a bore on a 6.4. Switched to a torque wrench at 28 ft-lbs like your old timer said and never went back. The injectors seat better without that shock load and idle smooth as butter now. Totally worth the extra few seconds per bolt.

wendy7219d ago

That old timer probably learned that trick the hard way after paying for someone else's mistake. Read a write-up from a Ford master tech who said those 6.7 hold-down bolts stretch real easy if you hammer them with an impact, and the torque spec is way lower than people think. He said the bore can get hairline cracks from the shock load and you'd never see it until the injector starts leaking or the engine sounds off. The stiction issue makes total sense too because a slightly loose hold-down lets the injector move around and messes up the seal. Honestly, that extra minute per bolt with a torque wrench beats having to pull the head to repair a cracked injector bore. People treat diesels like they need ugga dugga torque on everything but these newer engines are not that tough.