8.1 L Excessive Oil Consumption

sutak · August 29, 2003

My 8.1 engine seems to use oil when it is working harder. It happens at higher speeds (65-70mph), or when loaded. At 60 mph or less there is virtually no oil consumption. I can use up to 1/2 qt over as low as 500 miles, providing I work it hard.

The truck is still under warranty, but I can't decide whether I should insist on having it repaired or not. I hate to see anyone taking the engine apart.

Any suggestions where I could be losing that oil?

There are no sign of leaks on the driveway.

Larry.

2001 Chev K3500 CC LT 8.1L Ally 1000, 20000 miles

Hacksaw Hilliard · August 29, 2003

I read on another post about a TSB for these engines. If I recall correctly, the dealer had to confirm that oil consumption was more than 1 quart every 1,000 miles. My 8.1 uses oil too but at the rate of "only" 1 quart every 3,000 miles. Actually, that not too bad for me since I let the engine monitor my oil changes. I change out the filter every 3,000 miles and add 1.5 quarts to top it off. Since that equates to about 23% of oil capacity. I'm quite comfortable with the extended oil changes.

422 SS · August 30, 2003

Good luck getting them to fix it.I had to file suit and won a judgement for my 500 mile to the Qt 8.1.They will tell you thats normal for a 8.1.I have 58,000 miles on mine and while it's annoying to add a qt every 500 miles the engine still runs just fine.I will just change the plugs more frequently and drive it.I'm planning on trading it for a new GTO or Z06.

Shaners · August 30, 2003

It stinks that these bigblock engines use oil, and that GM hasn't found a cure for it yet... but that is the nature of the "beast" and that is the way it has always been...

HendyPhoto · August 30, 2003

I have had other trucks that burn way more oil than my 8.1 and they arent even big blocks. So I expected it from the beginning. All hard working trucks burn and will burn. I just dont understand why SO MANY trucks burn more than others, but it's all in how you use them I guess!!

04GMC8100HD · September 1, 2003

My 04 has 2400 miles on it and it's dropped about a 1/4 of a qt. Now this is not hauling anything, but there have been several 500 mile trips on the interstate, so I'm fairly pleased and anyway I'll be changing my oil every 3000 miles.

Randy

GMC8.1 · September 2, 2003

Mine has just over 14,000 now and I'm happy with it's oil consumption. We pulled our 5th wheel to Cananda and back, about 4,000 miles total, and it only burned a quart. Compare this to when it was "new" with less than 5,000 miles, it burned half a quart in less than 300 miles, towing. It doesn't burn much empty.