derka245

I just got a 2007 chevy Silverado 1500 with the 5.3L engine in it. I have heard horror stories about the AMF and how it is no good. But I do not know why it is so bad. how does it cause the truck to burn oil and how does it wreck the engine????

tech2

there is an oil pressure relief valve in the oil pan that discharges oil. this can under certain condition throw off too much oil that clogs the oil control rings. oil pulled through the pcv system is another way.


gm has corrected the issue by installing a shield over the relief valve and a revised rocker arm cover. So if your worried, buy the parts and install them.

derka245

Thanks but do you know how the AFM causes the oiling issues???

tech2

the relief valve is part of the afm system...so what I just said

lumberjack123

I am looking at a early 2007 Silverado with 5.3 liter, dealer swears that the early "Classic Style" 2007 models did not have AFM (which I don't want). How can I find out if it has this dreaded feature? I have the vin, but could not find out from sites I researched.

tech2

iirc look at the plate under the valley of the intake manifold. if its flat and smooth it will not have afm. if the plate is contoured, it does have afm.
I could be wrong on this. the best way is to the build shield in the glove box for the afm rpo code.