So Ive been burning a good amount of oil now. It happens mostly after the engine is hot and the RPMS go below 2000 rpm (taking off from stop lights, slowing and reaccelerating around corners, etc). When the engine gets really hot it will smoke on ignition as well. So I got a compression test.

If youre looking from the front of the car (in psi)

190 175
180 165
170 175

There didnt seem to be much oil on the plugs, though they were corroded pretty bad. My coolant needs to be topped off occasionally so Im not sure if the numbers are from the driver headgasket. Apart from the annoying valve tick, thats pretty much the story. 04 350z, 118k miles

Any suggestions? Im hoping its not the bottom end but Im preparing for the worst :/

 

You have a 14% difference between two cylinders, which is not ideal. The generally accepted rule of thumb is less than 10% difference between any two cylinders. Some people may say more is acceptable, others may say less. Regardless, your compression is not perfect and could definitely be the source of burning oil. Before jumping to conclusions, a leak down test is the next step so you can figure out if it's valve seals, piston rings, or head gasket. Losing coolant is a clue, but is there any oil in it?

 

Ill check again in the morning. Ive checked in the past and havent noticed any rainbows. Ill make a call about a leakdown test on Monday. It seems to be running fine otherwise. And it doesnt noticeably burn oil until I need to slow down enough for the RPMs to drop. Im awaiting the arrival of my oil cooler, definitely trying to get the most out of this engine