Need to add quart of two of oil every 1000 or so miles

[jdswather]

I recently purchased a 2007 Pontiac Grand Prix 5.3L MFI OHV 8cyl with 150k miles on it and it is burning a quart or two of oil every 1000 miles. The previous owner told me this was the case, but said he had it into the dealer many times and they could never find the leak and there is never any oil on the ground. The oil is obviously going somewhere but would love to figure out where. Any thoughts?

 

[Hurricane87]

I recently purchased a 2007 Pontiac Grand Prix 5.3L MFI OHV 8cyl with 150k miles on it and it is burning a quart or two of oil every 1000 miles. The previous owner told me this was the case, but said he had it into the dealer many times and they could never find the leak and there is never any oil on the ground. The oil is obviously going somewhere but would love to figure out where. Any thoughts?

The oil goes out the tailpipe every so often when you stop and shift down to first. Watch carefully the next time you're stopped, and you'll see a cloud of white smoke go out the back. You'll also find black residue in the exits of the tailpipes.

 

[Scottydoggs]

could have bad valve seals. if it smokes on start up after sitting over night thats generally the valve seals.

 

[Impala131]

I've read that 'Displacement on Demand' feature can accelerate oil loss on these cars. Also that the PCV system design can contribute as well. You might look up 'DoD disable' and 'catch can' for your model for more information on possible solutions.

 

[Jimsgxp]

Disable the dod system. The oil burning will stop.