A 2007 Duramax with a weird injector knock had me chasing my tail for a full weekend.

I swapped the injectors, checked the balance rates, and even pulled the valve covers before I found a tiny crack in a high-pressure fuel line fitting. How often do you guys see something simple like a bad line cause a noise that sounds exactly like a mechanical failure?

3 comments

3 Comments

troy4493mo ago

Honestly that sounds like a freak thing. A cracked line making that much racket? Seems hard to believe. Maybe the knock was something else and finding the crack was just luck. Those fittings are tough. Would need to see it myself to buy that was the only cause.

lunah863mo ago

Seen it happen before with high pressure lines. A hairline crack can whistle or knock like crazy under load. Trust me, you find the crack, you fix the noise.

angelab622mo ago

Back in '08 I had a 6.0 Powerstroke with a similar issue. Turned out to be a loose injector hold-down bolt. Made a knock that sounded just like a rod bearing. Swapped parts for two days before I found it. So yeah, cracks in lines happen but I'm with Troy on this one. Could be the crack was a coincidence and you just got lucky fixing it.

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