My 2003 Nissan Maxima seems to use oil. There is no leak that can be found. It does this especially on 70 MPH Interstate, etc.
A few more details, please.
Can you define “uses oil”?
Do you add 1 qt every 3k miles?
Every 1k miles?
Every 500 miles?
Every 100 miles?
How many miles are on the odometer?
How often is the oil changed–in terms of both odometer mileage and elapsed time?
When was the last time that you replaced the PCV valve?
It is normal for an engine to consume some oil.
The question is the rate being consumed or leaking out.
If you cannot find an external leak, the engine is burning it. A plugged PCV valve would cause an increase in oil burning at high speed. A worn out engine will, too. Please provide more info.
If you use the car mainly for short trip driving, that may mask the oil you are using between changes because you are getting unburnt gasoline and a little water in the crankcase so the dipstick still shows full.
Then when you go on a trip the engine gets nice and hot and evaporates off the water and gasoline and your dipstick level falls.
Yes, the case of the “mysterious disappearing oil”. This is a well documented situation, and very common when cars had carburetors; the choke-on cold operation would put a lot of raw gas into the oil.
I get oil change every 3000 miles. I usually end up adding oil at about 2000 miles later…not much…1/2 quart. SHould it always stay at the fullest level on the stick?
Odometer is at 127,000 plus. Have not replaced pcv valve in about 2 years.
In other words, the engine is consuming ~1/2 qt every 2k miles?
While this may be higher oil consumption than you used to experience, it is completely within normal consumption limits even for a brand new car.
In fact, most car manufacturers will tell concerned owners that adding 1 qt every 1,000 miles is “normal” for their newish car. Just be glad that you don’t own an Audi. Many Audi owners report that their engines consume 1 qt of oil ~every 600 miles, and they have been told that this is “normal”!
Continue to monitor the dipstick level every couple of weeks, just in case the rate of consumption increases suddenly. Right now, your rate of consumption is nothing to worry about for even a milisecond. If I were you, I would add oil as soon as it is down by 1/2 qt. Since that is what you are apparently doing, you are doing the right thing.
At 8 years and 125K miles, anything less than a quart per oil change is a blessing from the car gods.
Thanks for all who responding. This is reassuring, and a huge help!