It's AFM week.

4WD

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Update on the 2011 Denali Yukon XL, The #7 Intake Lifter was spinning in it's bore from a broken Lifter Guide Tray. Thankfully....The Camshaft is no worse for wear & was able to swap the 8 Lifters & the 2 Trays on that bank out for low mileage used ones.

Actually.....I had my "new hire" 2 year apprentice mechanic do the work on this one. Very proud of him for taking instruction & NOT complaining about working on a Saturday. He doesn't know he made $300 today.
Congrats on having an apprentice Chris - world needs to get back to those relationships 👍🏼
 

clinebarger

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Upon inspection of the Rockers & Pushrods.....3 had wear where Rocker pivots at the Pushrod, Not unusual on high mileage LSx engines. Melling was used for replacements.

Plugged the AFM oil pressure relief valve in the oil pan, It's technically Metric straight thread.....But, A 1/4" Pipe plug works great. Unfortunately not all 1/4" Pipe Plugs are created equal & the ones I sourced online just for this do not work well as they're on the small side. I had a 1/4"-1/8" NPT Bushing that worked well....Just had to plug it with a 1/8" Pipe plug.
*This is plugged because......
1. I'm using a HV Oil Pump.
2. It sprays down #7 piston when it pops off causing oil consumption.
3. It can stick open causing low oil pressure.
3. It's no longer needed because their are no AFM Solenoids to over pressurize.

Of coarse the Oil Pick Up Tube O-ring got changed, Likely needed one 50,000 miles ago!

I recommend ARP Exhaust Manifold Bolts anytime the Heads or the Engine is out on all LSx engines. I had to extract 5 broken manifold bolts using the Weld a Nut trick.

Recommended new Drive Belts, The A/C belt is pretty bad. Customer declined when I called this mourning even though I was going to sell them at cost & no additional labor is attached.....He called back at the end of the day giving the green light. I can kinda understand the "When is this going to stop feeling" though. This one wasn't too bad as I included most of the usual suspects in my original quote.

I seal off the VOLM (AFM Solenoid) connecter with RTV, While I doubt it would ever short against something.....I don't want to find out with a comeback.

Got to clean the Throttle Body, Install the Radiator & Fans, Air Intake, Connect the Exhaust Y-Pipe to the Manifolds, Install the front Crossmember, Antifreeze, Oil, Engine Sight Cover & the Tuning.

I offered to install a new Oil Drain Plug.....The customer stated that the socket (9/16") driven onto the plug is intentional as he could never find the right socket :)

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clinebarger

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Congrats on having an apprentice Chris - world needs to get back to those relationships 👍🏼

I agree 110%, That's how I got started in the industry instead of attending a Vocational/Trade school.....Not that there's anything wrong with trade school as it does lay some ground work that has to be learned the hard way in the field.

The issue lies with these kids thinking they'll be top dog in any shop just because they dropped $50-80,000 at a big name trade school. How much of the curriculum is actually absorbed by kids that probably didn't do that well in High School? Why are only the lowest achievers pushed toward Trades?
 
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I agree 110%, That's how I got started in the industry instead of attending a Vocational/Trade school.....Not that there's anything wrong with trade school as it does lay some ground work that has to be learned the hard way in the field.

The issue lies with these kids thinking they'll be top dog in any shop just because they dropped $50-80,000 at a big name trade school. How much of the curriculum is actually absorbed by kids that probably didn't do that well in High School? Why are only the lowest achievers pushed toward Trades?
I can't tell you how many guys came to our diesel generator shop over the years saying they went to Colorado Diesel. I'm sure it's a fine school. I never had one person come from there that worked out.
One guy came to work for me after getting broken in on engines in the Coast Guard. Now he starts up brand new gensets for Cummins. I'm like a proud poppa.
 
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love these posts - and great to hear about guys paying it forward to the next generation.

not to go off topic - are trade schools really $50-80k? I had no idea - do they leave with tools?
 
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Interesting thread! A few questions if you don't mind:
- what's the mileage on these two engines?
- how much does a repair of this sort cost?
- performance improvement from the replacement/upgrade parts?

jeff
 
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I second the interesting thread! Photos are great! Amazing resolution!

From what I have read, the dreaded lifter/bent pushrod issue still hounds GM to this day. I've read forums when even the new DFM (dynamic fuel management) has had issues. Possibly linked to batches of sub par lifters in conjunction with DFM. When I bought my '21 5.3 Silverado I made sure it's mfg date was later than what GM published as the suspect date range for the defective lifters. Also due to the chip shortage issue, mine has the DFM system disabled. Some have told me this makes my tuck more sellable in the future? Who knows?
 

clinebarger

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Interesting thread! A few questions if you don't mind:
- what's the mileage on these two engines?
- how much does a repair of this sort cost?
- performance improvement from the replacement/upgrade parts?

jeff

The 2008 Silverado 1500 has almost 250,000 & the 2011 Yukon Denali XL has almost 220,000.

The '08 final bill was $3,400 including Belts & replacing the worn Rockers & Pushrods, The 2011 Yukon final bill was $1020.

No performance improvements, The LQ9 cam is just the closest Non-AFM specification camshaft to a stock LMG camshaft. The "Bowtie" Lifters, LS2 Timing Chain, & LS2 Timing Damper are used for Durability reasons.

The HV Melling Oil Pump was used because the Low Hot Idle Oil Pressure it had when the '08 came in, I imagine it was even lower than 15 PSI on a hot summer day.
Admittedly.....I could've likely got by with a new GM Standard Volume Pump as the Oil Pressure is now 45 PSI at hot idle with the High Volume Pump. 30-35 PSI is ideal on a New LSx engine.
While I didn't hear any lower end noises....It's impossible for me to know all the Bearing Clearances without a complete teardown.
Unfortunately....Oil Pump replacement requires removal of the Timing Cover & Oil Pan, A little too much pressure is better than still having low hot oil pressure!
 
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love these posts - and great to hear about guys paying it forward to the next generation.

not to go off topic - are trade schools really $50-80k? I had no idea - do they leave with tools?
Yes they are that expensive. You get a good deal on SnapOn, but you don't leave with tools for the most part. I went to Santa Barbara City College and took the automotive program there instead of going to UTI. It was cheaper than high school (went to Catholic school) and I have done well since even though I work in parts.
 

clinebarger

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I second the interesting thread! Photos are great! Amazing resolution!

From what I have read, the dreaded lifter/bent pushrod issue still hounds GM to this day. I've read forums when even the new DFM (dynamic fuel management) has had issues. Possibly linked to batches of sub par lifters in conjunction with DFM. When I bought my '21 5.3 Silverado I made sure it's mfg date was later than what GM published as the suspect date range for the defective lifters. Also due to the chip shortage issue, mine has the DFM system disabled. Some have told me this makes my tuck more sellable in the future? Who knows?

Bent pushrods were never really an issue with Gen IV AFM engines, While it's much more prevalent on Gen V AFM engines. I haven't personally repaired a DFM engine yet.

Your truck will only be special as it remains in warranty as AFM & DFM is easily turned off via Tuning Software.

AFM/DFM Lifters will always have more issues than a standard hydraulic roller lifter which GM has been using the same basic one since 1986.
 
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Just a tip for anyone that doesn't know, in the photo without the exhaust manifold in place where you can see the engine mount, those stock mounts are huge and when they fail, I had to take mine apart to sneak it out past the manifold. I would have never been able to put another one back in. I somehow learned that police Tahoes use H3 engine mounts. They're considerably smaller and supposedly stronger. It falls right in.
It isn't as fancy as the bigger liquid filled mount and it's SLIGHTLY more harsh but after a couple of rides you don't even notice it.
 
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as always great post + pics!! glad i have RELIABLE VAG stuff!! traded my 2001 1.8T with 200 thou running great for a low mile 2001 TT 1.8T. two full timing belt jobs on the jetta one at 50 thou on the TT because car fax just said replaced belt + DIY jobs for me, much simpler than todays hi tech high dollar stuff!! 2011 fronty V-6 pickup is under 50 thou + would prolly get farmed out as the timing system looks to be a PITA especially at 73 YO
 
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