Got a 2015 GMC Sierra 1500 4X4 with 6.2L and max trailer package bought new.

Racing shop installed Whipple, cam, & long tubes at 20,000 miles in 07/2015 then BDS lift/35" tires, more boost and meth in 07/2016. Torque convertor failed leading to trans failure so Circle D pro series TC and new stock trans went in 01/2018.


Now engine has obvious valvetrain malfunction...
https://www.dropbox.com/s/26zsqwwwtz...netap.m4v?dl=0

Waiting on oil analysis and oil filter inspection to speculate on extent of damage.
So....if a engine rebuild is required should we keep as is, remove meth, lower boost and get some reliability? Or stroke? Contemplating repairing and selling for a diesel. The truck is fun but it's my DD and unreliability is no bueno.

 

How much boost was it currently at?

 

With what you've already invested I sure wouldn't jump ship because you wont recover your investment. Wait and see what you've got then decide. If it's bad then forge it. Diesels are expensive to buy and mod anyway and it wont be as fast. Good luck.

 

10 psi

 

meh its just a hamster wheel in there wouldn't worry about it.

 

I wouldn't go with a stroker, maybe bigger bore, and all forged goodies; especially if a DD reliable is your plan.

For now just cut open your filter,
drain the oil through a coffee filter (no need for blackstone oil analysis)
drop the oil pan if oil looks ugly and take a look at rods/bearings,
Take off a valve cover inspect,
then if needed maybe take off a cyl head or 2 for more evidence of motor go boom

Curious how much was the trans you just had rebuilt, have same issue with the 6l80 connverter causing all sorts of issues. Had I known would have swapped the circle-d from the start.

 

10 psi? that's it? I was running 11-13psi on my 5.3L without issue except it being a little rich.

Do the 6.2L have higher compression than the 5.3s? Maybe a tune issue that cause internal engine failure? Very curious.

 

Probably just bad luck. Mine showed 10lbs on 5.3 when dyno'd on the stock pulley and it drives fine so far for 24k mi since I did install.

 

GM 8L90E Automatic Transmission
- Requires Core
$2,933.00
Circle D Pro Series Torque Converter $1,200.00

plus labor and tune

 

shop said 10+ psi without meth was unsafe. Originally had only blower, cam, and headers on stock tires and settled on closer to 8 psi making 523hp/568tq with 3.75 pulley. Truck made only 5psi for boost with the 4.000" pulley, and produced 470rwhp/490rwtq. After adding the lift and 35" tires I was concerned that I'd loose alot of the seat of pants feel so went to 3.625" pulley and meth and made 525/543.

I like the idea of forged & larger bore, keeping blower but lowering boost and removing methanol. The truck is a beast and fun to drive it's just aggravating running out of meth once a month and it doesn't drive very smooth. It's either lugging or ***** out. Maybe it's tune.