6.0 oil consumption

[03chebby]

Looking for a little input on my 2003 1500hd with the 6.0 vortec. Over the last 4000 miles I have added 2 quarts of oil to the truck. I use Valvoline 5w30 full synthetic I have replaced the pcv valve and it hasn’t helped any  the truck has 171,000 miles on it. It used to only be down one hole on the stick between a 5000 mile change I noticed a few oil leaks but nothing major enough to where I should be putting a quart in it about every 2000 miles anyone ever have this issue?

[Black02Silverado]

Can't say this is the answer but on my 2002 with the 5.3, it developed an oil leak.  In the process of fixing that it also fixed my oil consumption.  I was using a qt in 6k miles.  Turns out what seemed to fix it was when I changed out the intake, valley cover and valve cover gaskets.  All that to stop the oil leak.  In the end my leak was the rear main seal, which was the last thing I did.

[CamGTP]

I would switch to a non full synthetic oil to see if the oil consumption drops.

[03chebby]

1 hour ago, Black02Silverado said:

Can't say this is the answer but on my 2002 with the 5.3, it developed an oil leak.  In the process of fixing that it also fixed my oil consumption.  I was using a qt in 6k miles.  Turns out what seemed to fix it was when I changed out the intake, valley cover and valve cover gaskets.  All that to stop the oil leak.  In the end my leak was the rear main seal, which was the last thing I did.

I did notice my valley is pretty soaked and I’m sure it’s time for intake gaskets on mine any way the rear main seeps a little I Just changed the valve cover gaskets I noticed some residue in the pvc ports on the valve cover I almost wonder if mine is clogged a little bit and letting a little bypass the rings only thing is I never see any blue smoke out the exhaust 

[Formulabruce]

Chances are the oil cooler lines to radiator are leaking as well. very common ..

[Black02Silverado]

2 hours ago, 03chebby said:

I did notice my valley is pretty soaked and I’m sure it’s time for intake gaskets on mine any way the rear main seeps a little I Just changed the valve cover gaskets I noticed some residue in the pvc ports on the valve cover I almost wonder if mine is clogged a little bit and letting a little bypass the rings only thing is I never see any blue smoke out the exhaust 

Mine would smoke out the exhaust on a cold start up after I did a long run up the interstate like 8hrs to my moms, or when I towed our 4k trailer.  After the intake gasket replacement that all cleared up.  I was surprised and pleased. 

[03chebby]

10 minutes ago, Formulabruce said:

Chances are the oil cooler lines to radiator are leaking as well. very common ..

Yeah their a little wet but not enough for 2 quarts between changes

[03chebby]

3 minutes ago, Black02Silverado said:

Mine would smoke out the exhaust on a cold start up after I did a long run up the interstate like 8hrs to my moms, or when I towed our 4k trailer.  After the intake gasket replacement that all cleared up.  I was surprised and pleased. 

I’m glad that worked out for you my next step is to do the knock sensors, plenum gasket, intake gaskets and the driver side valve cover hopefully that will bring it back to normal  oil just started disappearing all at once haha!

[Black02Silverado]

1 minute ago, 03chebby said:

I’m glad that worked out for you my next step is to do the knock sensors, plenum gasket, intake gaskets and the driver side valve cover hopefully that will bring it back to normal  oil just started disappearing all at once haha!

While your are there you can also make sure the oil pressure sensor is not leaking.  Mine had a little seepage.

[03chebby]

Just now, Black02Silverado said:

While your are there you can also make sure the oil pressure sensor is not leaking.  Mine had a little seepage.

Oh yeah I forgot about it!

[tigers2007]

If you have no leaks, consider using high-mileage oil. I switched to Supertech Synthetic High Mileage 5W-30 and my “missing oil” problem went away with my ‘02 2500HD.