Another AFM/DOD thread

[KRT]

Looks like GM’s AFM/DOD woes carried over into the GEN V LT/LS platform as well. 2017 Camaro SS with a 6.2





Notice the clearance between the rocker arm and valve stem compared to the others.



Collapsed AFM lifter

[Biggie1976]

Out of warranty?

[KRT]

Warranty ends at 60k

This one is out

[Biggie1976]

Damn that sucks

[Chessbay]

How exactly does that collapse? Is it seized inside causing the spring to collapse (or not rebound)?

[KRT]

How exactly does that collapse? Is it seized inside causing the spring to collapse (or not rebound)?

Yeah. GM kills oil to it to make it collapse then fires the oil to it to make it go to full extension. Sometimes it’s starved just right and it’s metal on metal and it seizes. The guy that continues to drive with lifter noise or a misfire ends up wiping out the cam.

I’ve read on here and other places that the GEN V DOD issues were resolved. Obviously not...

[Simple Man]

Engineers out-thinking themselves. Again.

[Foxtrot Uniform]

KRT have you done a AFM delete on an LT4?

[Gone South]

Yeah. GM kills oil to it to make it collapse then fires the oil to it to make it go to full extension. Sometimes it’s starved just right and it’s metal on metal and it seizes. The guy that continues to drive with lifter noise or a misfire ends up wiping out the cam.

I’ve read on here and other places that the GEN V DOD issues were resolved. Obviously not...

Good news though model year 20 and up 6.2L do not have AFM

[SaltMuck]

Only way I'd buy a Chevrolet at this point is if I needed another A2Z visor...

[Saltydog235]

Only way I'd buy a Chevrolet at this point is if I needed another A2Z visor...

No shit. Bought mine 3/14/20, I’ve been in it 14 days total. So far they’ve replaced the fuel pump, right fuel rail, left rail sensors, batteries, checked the entire wiring harness and connections and probably some other shit. Truck is to be replaced but no one knows when. I’m now in a 2020 AT4 2500 because evidently every two weeks they have to switch loaners.

It’s a shit show but I don’t have time to meet with the lawyer right now. So, I just take it day by day and laugh at the CS reps. Apparently they get quite offended when you tell them they’re being recorded too. They respond by email now which is what I wanted anyway.

Great riding/driving trucks too bad their engines are POS.

[KRT]

KRT have you done a AFM delete on an LT4?

I have.

[peedeeman]

I have 15 GMC with a 6.2 56000 miles. Has an intemit tick on the drivers side. Was told it was normal. Mechanic said it had something to do with the fuel system. Is this normal?

[KRT]

I have 15 GMC with a 6.2 56000 miles. Has an intemit tick on the drivers side. Was told it was normal. Mechanic said it had something to do with the fuel system. Is this normal?

So in 2014 GM went direct injection which requires a high pressure fuel pump. That pump has a noticeable tick at idle but it’s no lifter tick.

A lifter tick will change upon acceleration. The high pressure pump noise will stay consistent.