Collapsed Lifter - After 3000 miles!

[09Magic]

Can you tell us what your cold/hot idle oil pressure is? If it's not 40'ish cold or 25-30'ish hot, there's a chance that you've got a rotting/cracked o-ring at your oil pickup tube and you're sucking air. If your oil pressure is good, etc. then I'd look at replacing the VLOM. That's what sends high pressure oil to the AFM lifters to collapse them. The AFM lifters are durable and are sort of fail-safe (e.g. they use oil pressure to collapse them - not keep them extended), but they do not react well to a lack of oil or really dirty oil.

Anyone with an AFM motor such as the 5.3L LC9, etc. needs to be changing their oil every 3,000 miles without fail. Non AFM motors can handle longer intervals.

If you're pulling your heads off already, look into a bronze bushing trunnion upgrade as well. It's cheap insurance on high-mileage engines against loosing a needle bearing on your rocker arms. Any DIY person can do them.

 

[ezstriper]

agreed with above, need to replace the oil pump and O ring(very important) and my GM guy will never do this with out replacing the VLOM as well..

 

[harbison]

Skatejosh, I have had to replace one of my replacement AFM lifters that stuck just like the originals. This last time I had an engine shop do the AFM delete on the ECM using Diablosport. Cost somewhere between $100-150. That was 24,000 miles ago. Much less cost and labor than completely changing to non-AFM lifters. While you're at it, replace the left valve cover with the newer GM design. The PCV valve is built into the valve cover and when it becomes clogged it causes a lot of oil consumption and sludge.

 

[swathdiver]

So, I am stuck trying to figure out what has caused a lifter to collapse once again on me.

What did you end up doing Josh? I read recently that it is imperative that the latest VLOM be installed as the new lifters are only likely to fail due to incorrect VLOM timing or if they spin because of a broken lifter tray.