AFM

[RivGuy]

Excuse my ignorance to this topic, but I am a new owner of a used 2005 Silverado Z71 with a 5.3L engine.

I have been spending a lot of time on the forum just reading about stuff. The one thing I don't know is what the abbreviation of AFM means as related to the engine.

Please help me as I read about these engines consuming more oil than is expected. I only have about 300 miles since buying the truck and having the oil changed to what the factory recommends.

I figured with only 119,000 miles I shouldn't be worried about oil consumption but now I'm not so sure anymore.

Any input would be appreciated.

Thanks,

Rick

Edited July 11, 2019 by RivGuy

[RivGuy]

Excuse me, I just found it. Active Fuel Management.

Now, is there an explanation of this system (AFM) somewhere on the forum that I can read about and know if I have that or not.???

Thanks for any help Y'all can provide.

Rick

[swathdiver]

2 hours ago, RivGuy said:

Excuse me, I just found it. Active Fuel Management.

Now, is there an explanation of this system (AFM) somewhere on the forum that I can read about and know if I have that or not.???

Thanks for any help Y'all can provide.

Rick

Your engine does not have Active Fuel Management Rick.

 

AFM was introduced in 2005 for use with the Gen IV engines first used I believe on the GMT900 platform.  Your engine is Gen III and your truck is on the GMT800 platform.

 

Under low load conditions, oil is released through 4 solenoids to collapse the 8 lifters on four cylinders (1,4,6,7) which closes the valves and also shuts off the injectors and coils.  

Edited July 11, 2019 by swathdiver

[dsr611]

GM started putting the AFM crap in the Silverado/Sierra/Yukon/Tahoe 5.3 engines in 07...you do not have any AFM components in the 05.  In fact, when doing an AFM-DOD delete, you can replace all lifters and the cam in AFM engines with the lifters and cam from the GMT800 5.3 engines.

[Colossus]

And for your reference-  for the pre-2007 5.3L years, I suggest you use 5W30 FULL Synthetic oil (brand is not as important if you stick to the major brands like Valvoline, Quacker State, Pennsoil, and such, no need for the rip off stuff like Amsoil and Royal Purple unless you like throwing away money) being changed every 4000-5000 miles with a good premium filter (NAPA/WIX Gold or Platinum for example) should be an ideal oil change interval for your engine.  Check your oil levels once every few weeks or so just like we did back in the good old days.  You'll be set. 

[RivGuy]

Thanks for that info Ryan, I really appreciate it. I'll assume there is a good reason for using the 5W30 Synthetic over regular oil.?

I just replaced oil and filter after getting the truck, only about 3oo miles on it so far (119,700 total miles), but will definitely take your advice about using full synthetic oil during the next oil change and checking the oil level frequently.

As you can tell I'm new to this truck and these engines.

Edited July 12, 2019 by RivGuy

[dsr611]

On 7/12/2019 at 5:34 AM, RivGuy said:

Thanks for that info Ryan, I really appreciate it. I'll assume there is a good reason for using the 5W30 Synthetic over regular oil.?

I just replaced oil and filter after getting the truck, only about 3oo miles on it so far (119,700 total miles), but will definitely take your advice about using full synthetic oil during the next oil change and checking the oil level frequently.

As you can tell I'm new to this truck and these engines.

IMO, the 5.3 engines in the GMT800 line of trucks/SUVs is the best engines GM ever put out (not counting the carburated engines of the 80s...personally, I'd rather have a truck from the mid-80s than any of today's trucks).  My wife's 05 Tahoe has 290000 miles on it and the only "major" work I've done on it is changed that water pump a couple of years ago.  I'm getting ready to get her something else, and when I do, I'm thinking of doing some engine work on it and driving it myself.

[Gagliano7]

On 7/13/2019 at 12:53 PM, dsr611 said:

IMO, the 5.3 engines in the GMT800 line of trucks/SUVs is the best engines GM ever put out (not counting the carburated engines of the 80s...personally, I'd rather have a truck from the mid-80s than any of today's trucks).  My wife's 05 Tahoe has 290000 miles on it and the only "major" work I've done on it is changed that water pump a couple of years ago.  I'm getting ready to get her something else, and when I do, I'm thinking of doing some engine work on it and driving it myself.

I agree and the 4.8 and 6.0 of those years also run forever.