So I bought a 99 GSR with 116K miles on it. It doesn't smoke and nothing seems noticeably wrong with it. I did do a leak down and cylinder 4 has a slight leak. Pulled the spark plugs and the one in cylinder 4 was covered in white build up. Probably burned up oil residue. Has anybody had this problem with their car before? What, more than likely, is the cause of my car burning a quart of oil a week. Car still gets good gas mileage, and like I said it doesn't smoke until you're holding it at wide open throttle. Then some white smoke comes out the tail pipe. Any ideas would help a lot!

 

stuck oil control rings. or valve guides. most likely rings though.

 

Yea sounds like a stuck ring.

 

White smoke is coolant, blue smoke is oil. Have you checked for leaks on the valvecover and oil pan? Also, the spark plug grommets can cause oil to leak down into the cylinders and burn, although you would typically notice a bit of hesitation as the oil covers the spark plug.

The compression issue coupled with the miles on the car would lead me to think headgasket. A quick refresh of your high mileage engine wouldn't be a bad idea (valvecover, oil pan, and head gasket for starters)

 

As previously stated it sounds like the pistons rings are done.

 

where did the air leak down to when you performed the test? also, check/replace the pcv valve. sometimes it's as simple as that

 

That seems like alot of oil 1/4 a week, miles aren't that high does it use coolant also?
These motors are known to eat valve seals, there cheap but alot of work to change.