Why does nobody talk about the torque spec for injector hold-down bolts?

I had a 6.7 Powerstroke in the shop last month with a bad injector seal. The customer said he'd just done the job himself. I pulled the valve cover and found three of the four hold-down bolts were barely finger tight. He told me he 'snugged them up good' but didn't use a torque wrench. That extra 15 foot-pounds matters a lot to keep the injector seated right against the high pressure. How many of you have seen this cause a comeback?

3 comments

3 Comments

harris.andrew29d ago

Honestly that "snugged them up good" line is the whole problem right there. People think they know what tight feels like but they're always way off, especially on small bolts. I've seen this exact thing cause a comeback on a Duramax where the injector was basically floating in the bore. Tbh it's not just about the seal, that uneven clamping force can crack the hold down itself over time.

rowanw1129d ago

My old torque wrench habits changed after a cracked hold-down cost me a weekend.

dereks1129d ago

Yeah that's a perfect example of what @harris.andrew is saying. It's this whole thing where people guess at stuff that needs to be exact. I mean you see it everywhere, not just with cars. People eyeball measurements, skip steps, think "close enough" is good enough. But with something like injector pressure, close enough is a leak and a comeback. That specific torque keeps everything square and sealed. Just cranking it till it feels tight almost always means it's either way too loose or you're about to strip something.