GM Injectors

Charlie D. wrote:
Anyone else receive their letter extending the warranty on indirect fuel injectors to 10 years or 120,000 miles?

I have done a little Googling but fail to understand what the indirect inject is. I assume they are not talking about a single injector that is separate from the other 8. This would be the 8 used to fuel the engine?This is not a recall.

Duramax is a direct injection engine for the 8 cylinders. On later units with DPF and DEF and the LML engine they added a "9th" injector in the exhaust line to inject fuel to get the exhaust hot enough to do the DPF regeneration.

Earlier units with DPF and DEF did it somewhat different IIRC and didn't use the 9th injector. I think they did an injection squirt during the engine exhaust stroke to heat up the exhaust.

I was not sure what it was but I looked up indirect injection and there is a good article on Wikipedia on indirect injection. Might be worth reading. JMO

Got mine, put it in the truck for future reference. Don't know what the symptons are or will be, but the letter will be there if it happens.

Haven't seen the letter, but I assume it is the 9th injector in the exhaust used when it burns clean the DPF.