[LT4Greg]

I wonder what Steve V replied that maybe using the new oil in the older LT4 engines contributes to higher oil consumption especially when driving more aggressively with it floored most of the time.

[minn19]

After having two GT350s I’m very sensitive to this issue. I broke mine in according to manual and have done the two break in oil changes in the first 2k miles. All oil has been the Dexos 2 0W-40. After the 1500 mile break in, I’ve had some fun with it and to my amazement I’ve apparently never used any noticeable amount of oil. It now has about 3k on the engine. I’m very happy about this after the bullshit with the Voodoo motors and obviously hope this continues.

[donaldp]

Originally Posted by donaldp

I change my oil every 5,000 miles with 10.5 quarts of Mobil 1. I add 4.5 quarts between each oil change and have been documenting this. I buy three 5 quart jugs every 5,000 miles and use it all. I essentially burn 1 qt every 1,000 miles. This is excessive and i will present this to the dealer before my warranty on my 17 ZL1 is up in March. I've heard others have had engines replaced with this excessive use. Unfortunately, it's not uncommon.

Update: I've taken my ZL1 to the dealer for the first time in my almost three years of ownership. No oil consumption test was performed because they based their decision to investigate further upon my records of adding oil to the engine.

I was told that the likely cause of my excessive oil consumption, which GM defines as more than one quart per 2,000 miles, was either:

1. Bad Valve seals or
2. Piston Rings

They removed the Supercharger and looked for oil on the top of the engine. If found they would be confident that the problem was bad valve seals.

If no oil was found they would be confident that there were bad piston rings.

I heard back this morning that oil was found on the top of the engine thereby all but eliminating the piston rings as the cause and pointing the blame at the valve seals. The valve seals have been ordered from GM and that repair will be completed under warranty. Had their been no oil on top, they were going to tear the engine down and replace all the pistons.

I'm not knowledgable enough so I'm hoping you all can weigh in on this and let me know if it makes sense to you, especially you motor heads.

[Zigg L1]

I drive my car pretty hard IMO. I use the slap shift option vs the paddles for fun. I add about 1qt every oil change 3500miles +/-. One change per season

[Mark R]

Originally Posted by donaldp

Update: I've taken my ZL1 to the dealer for the first time in my almost three years of ownership. No oil consumption test was performed because they based their decision to investigate further upon my records of adding oil to the engine.

I was told that the likely cause of my excessive oil consumption, which GM defines as more than one quart per 2,000 miles, was either:

1. Bad Valve seals or
2. Piston Rings

They removed the Supercharger and looked for oil on the top of the engine. If found they would be confident that the problem was bad valve seals.

If no oil was found they would be confident that there were bad piston rings.

I heard back this morning that oil was found on the top of the engine thereby all but eliminating the piston rings as the cause and pointing the blame at the valve seals. The valve seals have been ordered from GM and that repair will be completed under warranty. Had their been no oil on top, they were going to tear the engine down and replace all the pistons.

I'm not knowledgable enough so I'm hoping you all can weigh in on this and let me know if it makes sense to you, especially you motor heads.

I think the most important thing is that the dealer accepted your own documentation of the problem, ànd started tearinģ into your engine to fix it, rather than denyinģ that you have a problem. It's a good start.