2013 LT - PCV change (i.e. valve cover change) engine code LMG

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

DrNick

TYF Newbie
Joined
Jun 25, 2020
Posts
13
Reaction score
4
Hi All. (Accidentally posted in wrong model year forum) 00-06

115k on my 13 LT z71 Tahoe. At the 100k noticed a bit of oil leak around valve cover and driver side plugs were black. Getting a bit worse on oil presence and some oil consumption, concerns in last oil change, although “within GM specs.” Truck still runs great.

The PCV might be misbehaving causing this leak and is part of the valve cover leaking :). Can this (the pcv) be cleaned while the valve cover is off or should the valve cover just be completely replaced to get the fresh pcv and new gaskets/grommets on both? I will do hose too. Note, as far as I can tell in TSB, this truck should have the new ports. I think it said cutoff was 2011 build for the old valve cover PCV port ones.

will attempt both sides.
 

rdhogg

Full Access Member
Joined
Oct 28, 2011
Posts
491
Reaction score
1,246
Location
Houston
My 2013 HOE has the old style Valve cover (on the drivers side), I am waiting on the new style to arrive, do the modifications on it and install it. Did research on the "Oil consumption on 07-14 GM 5.3 trucks" issues on YouTube , found several videos, DYI'ers were modifying the old cover and reinstalling. The new style (GM OEM) from RockAuto is only $64 + tax and freight , the only mod needed is to enlarge the PVC drain hole in the baffle , clean the shavings WELL and install. New cover comes with new gasket and all. I will update this reply when I get some miles on the new cover. BTW I also put a 'tune' on to turn off the AFM , that was a another factor that was adding to the oil consumption.
 

PG01

Supporting Member
Joined
Nov 6, 2016
Posts
14,899
Reaction score
18,299
Location
Up here to the right
My 2013 HOE has the old style Valve cover (on the drivers side), I am waiting on the new style to arrive, do the modifications on it and install it. Did research on the "Oil consumption on 07-14 GM 5.3 trucks" issues on YouTube , found several videos, DYI'ers were modifying the old cover and reinstalling. The new style (GM OEM) from RockAuto is only $64 + tax and freight , the only mod needed is to enlarge the PVC drain hole in the baffle , clean the shavings WELL and install. New cover comes with new gasket and all. I will update this reply when I get some miles on the new cover. BTW I also put a 'tune' on to turn off the AFM , that was a another factor that was adding to the oil consumption.
You sure about that updated valve cover bud? I’d take another look if I were you.
 

PG01

Supporting Member
Joined
Nov 6, 2016
Posts
14,899
Reaction score
18,299
Location
Up here to the right
No, the one in your 13 now. As far as I know, which ain’t much tbh, they started using them in 11-12 to combat the known issue. Maybe some swapped yours with and older one?
 

rdhogg

Full Access Member
Joined
Oct 28, 2011
Posts
491
Reaction score
1,246
Location
Houston
I was going on what my Mechanic said, I have not taken it off yet, but have ordered the new one. I will let you know when I take the old one off. Thanks for the heads up.
 

donjetman

Full Access Member
Joined
Oct 22, 2018
Posts
1,531
Reaction score
2,714
I believe your 2013 HOE came from the factory with the new improved valve cover. Below is a pic of my dirty old vc(top) off my 07 6.2L, and my new improved vc(bottom). Look at the upper right of each. The new improved vc has a square pvc port with flaps, the old has a round port. You'll know when you get yours off.DSCN0080.JPG
 

rdhogg

Full Access Member
Joined
Oct 28, 2011
Posts
491
Reaction score
1,246
Location
Houston
You sure about that updated valve cover bud? I’d take another look if I were you.
2013 Tahoe new valve cover PVC drain enlarged to five thirty seconds_LI.jpg 2013 Tahoe clean valve lifters.jpg 2013 Tahoe old valve cover.jpg 2013 Tahoe new valve cover std PVC drain  size seven sixty fourths.jpg You were 100% correct, the 2013 has the new style valve cover , but the drain hole in the PVC drain was patricianly clogged. I have a 2013 Tahoe with 130,000 miles and noticed having to add 1-3 qt oil between changes. Researched WWW and found one issue was the drivers side valve cover design and GM finally changed the design. I found out that about 2011-2012 the new design started being put on. All my process of elimination still pointed to the cover with PVC drain hole getting clogged. I ordered a new GM OEM part # 12642655 from RockAuto , all gaskets and bolts ( about $70.00). I enlarged the std 7/64 drain hole in the PVC baffle to a 5/32 hole, I also put additional drain below the baffle plate. I removed my original valve cover and found that the PVC drain hole was slightly clogged and most likely causing oil to be sucked back into the intake. I could have put in a catch can but wanted to try this first. The top end looks real clean, due to scheduled oil changes and all lifers are tight without any play. I have included some pictures of the old cover ( the clog is hard to see) and the new cover with the modified drain hole. I will monitor the oil consumption.
 
Last edited:

donjetman

Full Access Member
Joined
Oct 22, 2018
Posts
1,531
Reaction score
2,714
yes you do have the new improved valve cover.

You shouldn't be consuming that amount of oil between changes. If you had a catch can, you would know if it was being sucked to the intake. It could be getting by the rings and/or valve seals. If it's the rings, they may be stuck, in which case you need to do the cylinder soak like I did with a solvent like Gunk brand Motor Medic.
 
Last edited:

rdhogg

Full Access Member
Joined
Oct 28, 2011
Posts
491
Reaction score
1,246
Location
Houston
yes you do have the new improved valve cover.

You shouldn't be consuming that amount of oil between changes. If you had a catch can, you would know if it being sucked to the intake. It could be getting by the rings and/or valve seals. If it's the rings, they may be stuck, in which case you need to do the cylinder soak like I did with a solvent like Gunk brand Motor Medic.
The next project for me is the catch can, can't hurt.
 

Forum statistics

Threads
132,321
Posts
1,865,954
Members
96,912
Latest member
Papaskip
Top