Anyting I can do to prevent AFM issues?

[swathdiver]

Looks good and that is the old valve cover, not the new and improved one which is 12570427 for 2007-2008.

Keep the oil clean. Take a picture of the underside of the intake where the VLOM is, maybe we can tell if you have the new one or the old one.

 

[Roger08LTZ]

What's the new and improved valve cover do? Seems to me as long as it's keeping the oil inside the engine, it's good.

Here is a shot of my valley. It sure looks original.

 

[swathdiver]

What's the new and improved valve cover do? Seems to me as long as it's keeping the oil inside the engine, it's good.

Here is a shot of my valley. It sure looks original.

It helps to reduce oil consumption. If you're not consuming oil, don't bother.

That is the new VLOM. It was introduced in 2011. My motor got a new one in 2016 at about 100K miles and AFM was turned off in the tune 18K miles afterwards.

Most AFM failures occur because the VLOM solenoids get out of time, usually because of dirty oil, which causes the lifters to jam and fail and maybe bend a pushrod or more as well.

 

[Roger08LTZ]

It helps to reduce oil consumption. If you're not consuming oil, don't bother.

That is the new VLOM. It was introduced in 2011. My motor got a new one in 2016 at about 100K miles and AFM was turned off in the tune 18K miles afterwards.

Most AFM failures occur because the VLOM solenoids get out of time, usually because of dirty oil, which causes the lifters to jam and fail and maybe bend a pushrod or more as well.

Two questions, as shown on one of the pictures one of my rockers looks black. Anything to worry about? The other thing I've been told these LS type engines have needle bearings in the rockers that are prone to failure and that it's common to convert to a bushing instead. Is that something relevant to the 5.3 or just the real LS engines like the LS1 etc.?

Thanks!

 

[iamdub]

The new PCM is in and I did the Crank relearn, no problem. No other errors.

I also took off the valve cover. It looks good especially for 190+K miles

View attachment 381161View attachment 381162View attachment 381163View attachment 381164

Awesome! Yeah, it looks pretty good in there, especially for the mileage.

Two questions, as shown on one of the pictures one of my rockers looks black. Anything to worry about? The other thing I've been told these LS type engines have needle bearings in the rockers that are prone to failure and that it's common to convert to a bushing instead. Is that something relevant to the 5.3 or just the real LS engines like the LS1 etc.?

Thanks!

I'm wondering if that rocker is in line with the hole in the PCV baffle and it's just from years of oil dripping back onto it and cooling when parked. It's great that you don't have any or much oil consumption, but I'd still get that updated cover.

I wouldn't say the stock rocker bearings are "prone to failure". At least, not in a stock setup. They're the same rocker design used across all LS engines including the high-performance car variants spinning 7,000 RPM and with more cam action happening. To me, the reports of their failure has become more of a Hegelian dialectic. I'd trust the stock ones over the bushing style. I researched stock and aftermarket needle bearings versus the various bushing styles to exhaustion a few months ago. My TSP cam is decently comparable to a stock LS6 cam and I have the "heavier duty" LS6 valve springs and my redline is about 600 RPM less than that of the LS6. I decided that if stock rockers do fine in an LS6, they'd be fine in my warmed over LMG. Problems arise with stock bearings (and still with the aftermarket bushings) on more heavily modded engines with big cams, high spring pressures, higher RPM, etc. I did my engine refresh at 200K and put the original rockers back in with the intent to swap them later once I had settled on some aftermarket ones. They did just fine with all the "abuse" following the refresh with upgrades, but I wanted the peace of mind of at least having something new. Back in May, I bought 16 new GM OEM rockers off eBay for $9.99 each and haven't given it a second thought. If I were to go aftermarket, these are what I'd get: http://www.ws6project.com/user_stor...cts_id=9356&osCsid=med8ej8uujfipsmotus6cus9s1

 

[Geotrash]

+1 on the stock rockers being good to go. The reports of failures were from very early LS engines and I've seen zero reported failures in the last 15 years in any of the forums. I researched before I did my cam swap. I did end up going with the Brian Tooley Trunnion upgrade kit but if I had it to do over again, I wouldn't bother. I would worry more about the valve springs.

 

[Roger08LTZ]

Awesome! Yeah, it looks pretty good in there, especially for the mileage.




I'm wondering if that rocker is in line with the hole in the PCV baffle and it's just from years of oil dripping back onto it and cooling when parked. It's great that you don't have any or much oil consumption, but I'd still get that updated cover.

I wouldn't say the stock rocker bearings are "prone to failure". At least, not in a stock setup. They're the same rocker design used across all LS engines including the high-performance car variants spinning 7,000 RPM and with more cam action happening. To me, the reports of their failure has become more of a Hegelian dialectic. I'd trust the stock ones over the bushing style. I researched stock and aftermarket needle bearings versus the various bushing styles to exhaustion a few months ago. My TSP cam is decently comparable to a stock LS6 cam and I have the "heavier duty" LS6 valve springs and my redline is about 600 RPM less than that of the LS6. I decided that if stock rockers do fine in an LS6, they'd be fine in my warmed over LMG. Problems arise with stock bearings (and still with the aftermarket bushings) on more heavily modded engines with big cams, high spring pressures, higher RPM, etc. I did my engine refresh at 200K and put the original rockers back in with the intent to swap them later once I had settled on some aftermarket ones. They did just fine with all the "abuse" following the refresh with upgrades, but I wanted the peace of mind of at least having something new. Back in May, I bought 16 new GM OEM rockers off eBay for $9.99 each and haven't given it a second thought. If I were to go aftermarket, these are what I'd get: http://www.ws6project.com/user_stor...cts_id=9356&osCsid=med8ej8uujfipsmotus6cus9s1

I'm going to leave the rockers alone. The people telling me this are track racers with tube chassis dedicated race cars running LS3's. They might be pushing their motors a tad bit harder than my wife and I are in the Tahoe.

 

[Foggy]

The OE rockers fail mostly due to high lift camshafts...
They can only rotate a limited amount of degrees... So with stock lift numbers,
generally under .540 ish, there is no reason to change.. But once you get more lift
and of course then you need more spring pressure, they can fail.
I did the bushing upgrade on mine since my new cam is .560 ish lift and for
cheap insurance against a breakdown.

 

[swathdiver]

Two questions, as shown on one of the pictures one of my rockers looks black. Anything to worry about?

I did see that and thought to myself that if it had gotten hot, it would be kinda blue. A lot of these motors had AFM failures by around 100K and if caught early were easily repaired with the latest parts with no damage to the engines.

When these engines first came out, the Avalanche guys were tweaking the computers to get even better gas mileage out of them, up to 26 mpgs on four cylinders if memory serves.

 

[fozzi58]

these engines first came out, the Avalanche guys were tweaking the computers to get even better gas mileage out of them, up to 26

That was me. Had an '08 Avy with 160k+ on the clock when I sold it. I had a hand held tuner that I set engine management to economy. Was easily getting 30+ mpg on highway. Bought the truck in 2008 used with 8500 miles on it (basically new), and had it until I bought my 17 burb. I did oil changes early and often. I think I went 5000 miles on the oil once in all the years I owned it, otherwise oil change every 3k miles. Never had a lifter failure. She ran perfect the whole time I owned her. Wish I could say the same for the transmission!