Hopefully you will share your findings, your knowledge learned and pictures of gdi equinox and terrain GDI engines with us as you do rebuilds.
Answering your original question,
both rings and piston are replaced under GM warrantee, according to gmTechlink. (see below)
Your other question is not known for certainty
But I have read of folks who have had the piston and rings replaced, only to have the oil consumption issue return
I believe Oil consumption still occurs on newer engines that were built with new piston and rings
.... all gdi engines will burn oil eventually unless ....
Gdi engines suffer from carbon build up on intake valves, as explained by Mr. Dickmeyer, in sydnesb's above link.
GDI Design Flaws
it’s almost like the crankcase ventilation system was an afterthought.
“On the EcoTec GM 2.4L engine, the inlet where the plastic intake manifold meets the heads for the crankcase ventilation system
is down in a low spot
that you would normally see an oil drain back passage through,”
“So you get oil that as it works its way through the engine and comes up to the top end and then works its way back down and falls to these low spots.
That’s where .... the vacuum source for the crankcase ventilation system, so they’re sucking in oil.
"“We coated the backsides of the valves,”
“I then added an oil separator to the intake system
we coated the entire skirt of the pistons with PTFE moly coating.
We coated the top and the underside with a heat barrier
and at 40,000 miles we pulled the intake manifold off this vehicle and there was little to no build up.
^^^^^. Mr. Dickmeyer^^^^^
Since the PCV is internal to engine, I don't know how Mr. Dickmeyer added an oil separator (catch can) to the internal PCV orifice ......
Unless he plugged up the internal 80 thousands of an inch diameter internal PCV orifice in the intake manifold
add a new hole in top of crankcase, and a new PCV orifice, with an external hose, a catchcan and then a new hole "somewhere" to return the crankcase gasses to the intake manifold or intake ports .....
( that ^^ is a good idea for you)
while I understand coating of valve stem and top side of intake valve with "teflon" , but pistons
And inside of engine part-of-the-valve with an heat insulator? (What is heat resistant coating flakes off
((same with the teflon coating)), would it trash cat converter, jam in piston rings? Who knows?)
Since a theory is that carbon falling off intake valves, via LSPI, scratches cylinder walls,
during your tear downs and rebuilds, could you carefully examine cylinder walls for scratches, which might allow piston blow by and oil consumption.
Or is it actual grooves in pistons, into which rings attach that is damaged by carbon and then allows piston blowby ?
Also, in the oil control rings, are the tiny holes , are those plugged up with carbon or gunk?
Let's us know your observations
Around here, where we have temperatures around 10 degrees F in winter and colder, these engines suffer from crankshaft rear main seal failures. The plastic nylon orifice of the dirty side PCV inside the engine, plugs up, bonds with the engine oil sludge, (like varnish on metal?) coupled with piston ring blowby,
Pushes crankcase gunk up and out the clean side PCV breather hose, and if cold enough, it freezes solid...
with enough crankcase pressure from piston blowby
a hole is blown thru viton rear main seal at sharp corner where living hinge attaches to overmolded steel ring.
Yes a hole, and then catastrophic failure as engine oil is squirted onto pavement
(Are aftermarket rear main seals a better quality?)
The Mr. Dickmeyer external Dirtyside PCV with catchcan idea, should prevent crankshaft rear main seal failure
Not much is known of the specifics of the 5-25-2013 running change piston ring upgrade
.... Below is from gm techlink.....
2.4L Ecotec Engine Oil Consumption
August 6, 2013
Excessive oil consumption on some 2010-2013 LaCrosse, Equinox, Terrain and 2011-2013 Regal models equipped with the 2.4L engine (RPOs LAF, LEA) does not require engine replacement. If excessive oil consumption is confirmed after an oil consumption test, new pistons and piston rings should be installed.
Piston Ring Coating
The top compression ring in the new kit has a more robust coating on it that is designed not to wear as quickly as the original coating. Tests indicate that it wears about 4-5 times longer than the original coating.
If the top compression ring is worn, it will allow combustion pressure past it, which causes the oil control rings to be less effective and results in excessive oil consumption.
On 2010-2011 vehicles built before March 2011, there is a strong correlation between leaking high pressure fuel pumps diluting the oil and causing the ring wear. Due to this, check the fuel pump, balance chain, balance chain tensioner and timing chain for the proper part numbers. The updated fuel pump has an enhanced seal.
If these updated parts have not been installed during a previous repair, they should be replaced when the pistons and rings are replaced. Use field action #12313 if the balance chain and/or fuel pump is replaced.
The pistons must be replaced because as the rings wear down, it starts to widen the piston ring groves. The worn grooves will not retain the new rings correctly.
The “zebra” stripping on the bore surface (Fig. 1) is not an indication of a cylinder bore abnormality, but rather a transfer of the ring material as it was worn down. The bores are still uniform and the new rings seal. The validation of the new ring pack was done on used blocks that had zebra striping. It’s not necessary to do any surface treatment to the zebra striped bores when installing the new pistons and rings.
^^^^^ techlink_aug_f01. ^^^^^
To be clear,
zebra stripes is different then combustion chamber wall scouring. Combustion wall scouring occurs when carbon from GDI intake valves falls into combustion chambers and scratched cylinder walls.
Zebra stripes is the transfer of piston ring plating to the cylinder walls.
My 2 cents ^^^^^