My 04 g35 has been having oil consumption problems, but the compression tests come back fine and no oil is leaking out of the engine. What else can be causing the oil to burn. Is it possible for me to have normal compression and still burn oil? Its consuming almost 1qt every 1k miles....

 

bump anyone????

 

What about the possibility of an oil leak above the exhaust manifold (so the oil is burned off).

 

what's your mileage? I noticed more and more 04's are claiming this problem.

 

The usual problem is the weak tensioned thin upper oil ring which sucks upward during deceleration.

A running compression vs a static cranking compresion test.

Increasing the viscosity to say a 10/5/0w40 synthetic should increase oil mileage.

The ultimate problem is the potential for shorting cat life due to all the oil additives burned. But most sell cars before 150k so the problem gets transfered.

Low thin tensioned rings is a great way for engineers to increase power by lowering friction. NASCAR does it so well they burn a quart every 40 miles and hold 20 quarts.

 

Doubt the OP is paying this thread any attention, but changing the PCV valve is another option to consider. Putting a catch can off of the PCV valve is another good idea that will let you monitor oil vapor collection via that system and prevent reingestion.

 

what kind of oil are you using? some people have listed different types of oil having different oil consumption rates. Like the everyone else said. Try using a different 5W30 or a differernt "weight"/grade of oil. Then post back and see if that helps.

 

Using a higher viscosity hot number 30>40>50 will of course decrease oil consumption at a minor increase in fuel consumption.

Remember you can blend same brand viscosities to create 35 or 45 top numbers.

Just as so called High Mileage oils run at the very top of viscosity specification, where a High Mileage 30 may be a 34.99 instead of a 28.

 

Sorry to bring back this thread from the dead, but my 05 revup is seeming to have the same issue. 156K on the clock, usually burnt around 1 quart every oil change 15000 miles ago, (normal) until progressively getting worse around 15,000 miles ago, and now its burning more, around 1.5 quarts per 1000 miles with baby driving. 95% my miles on the car have been at cruise control at 58 mph. (no reason to lie to you all here) That said, for S and G's, I drove the car moderately harder, with a few pulls and average highway speed cruising around 70-80 for 1000 miles to test consumption... My oil consumption was the same. Havent done compression check but my car runs tip top, starts perfectly fine, no smoke, and when crusing 60 mph, Im getting over 30 mpg's. (31 to be exact) I'm praying its just a bad PCV valve; I bought one over the weekend and install it next weekend. I am convinced it is that, because I cant get myself to think it's the rings. Not only that, this may sound odd, but I swear my PCV valve makes a weird "TSSSSSSSSSSS" hissing noise after driving. I'm thinking the ball valve in the PCV valve is sticking or something. I always check oil levels, and the car has had nothing but SynPower 5W-30 at 3,000 miles or less for over 60K miles. (Since I began owning it 7 years ago.) I've looked up symptoms of bad PCV valves, and usually they'll start causing vacuum issues or fouled plugs, but I haven't had that. I'm praying it's just half failing and my rings aren't shot. Any idea about my theory?

 

PCV, could also be an intake manifold leak allowing oil to be drawn into the intake.