Update!

[98 Z71 SLT]

GM bulletin just released 8-24-10

 

10-06-01-008

 

GM has finally admitted problems with the aluminum block, AFM equipped 5.3 engines. Reports show some customers burning a quart of oil in 800 miles.

 

For now, the AFM lifters are no longer "over-active"

 

Now, there's a new theory. GM states that there is a new design oil scraper that is to now be used, to shield the pistons from nearby AFM valve oil splash. To install this special part, the oil pan must be dropped and reinstalled.

 

It's their words...not mine

 

At the dealer, we did our 1st one today...following this bulletin...

 

THEN, this new bulletin states...if oil burning DOES continue, the customer is to get new pistons and rings

 

Wow...whatchya think guys???

[oldschool327]

So this is just for the Aluminum 5.3? What is the Solution for old Ironside blocks?

[sc4808]

Good info, thanks for the update.

 

So far I have had no issue, I am at 55K now

[98 Z71 SLT]

So far, after reading thru the TSB, it seems like the aluminum block is the biggest offender...

[Bowtie2Sierra]

It is good that they are acknowledging some sort of problem regardless of how isolated it may be. I have had zero issues with both AFM 5.3 engines that I have owned. I know many people with zero problems also and only have heard of problems on this forum.

[98 Z71 SLT]

At the store, we have a good customer with a ton of patience.

 

900-series Sierra, has always been an oil-burner

 

New valve cover

 

New lifters-all lifters

 

Lots of this...lots of that

 

Nothing ever fixed his oil burning problem

 

Now we'll see if this scraper does any good...

[sc4808]

At the store, we have a good customer with a ton of patience.

 

900-series Sierra, has always been an oil-burner

 

New valve cover

 

New lifters-all lifters

 

Lots of this...lots of that

 

Nothing ever fixed his oil burning problem

 

Now we'll see if this scraper does any good...

 

Keep us updated please

[jro909]

what an eyesore...why not just scrap afm and disable it as a whole on trucks...if people drove with less of a lead foot the goverment woulden't be dogging so hard for better mpgs, hell i get 20 mpg on the highway with 8 cyclinders banging away

[Ryan00TJ]

GM bulletin just released 8-24-10

 

10-06-01-008

 

GM has finally admitted problems with the aluminum block, AFM equipped 5.3 engines. Reports show some customers burning a quart of oil in 800 miles.

 

For now, the AFM lifters are no longer "over-active"

 

Now, there's a new theory. GM states that there is a new design oil scraper that is to now be used, to shield the pistons from nearby AFM valve oil splash. To install this special part, the oil pan must be dropped and reinstalled.

 

It's their words...not mine

 

At the dealer, we did our 1st one today...following this bulletin...

 

THEN, this new bulletin states...if oil burning DOES continue, the customer is to get new pistons and rings

 

Wow...whatchya think guys???

 

 

I find this hard to believe from GM. What differences are there from the iron to alum block engines aside from block material. They would have to be the same to keep parts interchange easily accesible. Could it be greater tolerances on the Alum block engines? I am glad my ext cab has an LY5 iron block 5.3L with no oil burning problems to worry about and AFM works flawlessly. Knocks on wood..... Interesting to see if this works???

 

Interesting that they want dealers to replace the piston and rings if the scraper does not work!! What are new pistons and rings going to do if they are still getting concentrated oil splash? Leads me to kinda believe the whole problem lies in the pistons and rings tolerances to begin with. Kinda a hark back to the LS1 days.

[fraiolib]

can a gm dealer turn off afm?? or only a custom tune?

[stefman722]

How do you know if you got the alum. block?

[RyanbabZ71]

How do you know if you got the alum. block?

 

Engine code, glovebox or window sticker

[4wd]

How do you know if you got the alum. block?

 

RPO code LC9

[gnet158]

So this is just for the Aluminum 5.3? What is the Solution for old Ironside blocks?

 

Didn't know this effected the Iron blocks too? I have an Iron block and haven't had any oil loss with 30K on the clock. Are you loosing oil?

[441G]

put me on the oil burner list - no problems until last sunday, started truck and message said low engine oil. i shut off engine and there is just a drop on the bottom of the stick - it took 1.5 quarts to put her at the top. never used oil until now - 07 nbs ly5 iron block 56,888 miles.btw we have a fleet of 5.3 afm trucks at work and alot of them are using oil. GM says 1qt per 2,000 miles is acceptable.