I know that motor oil gets vaporized or disintegrates after some period of time, even in healthy engines. Generally speaking, how much time or how many miles will pass before you have to add motor oil? And how much oil would be disintegrated in a healthy engine?

I have a 92' Ford Ranger with a 2.9 V6. This engine is nine months old.

 

On a healthy motor you will get to the next oil change interval before the oil level dropped enogh that you needd to add more. If the oil level is dropping considerably before 3k miles from the last oil change then there is a problem somewhere.

 

It depends on the engine.
See what Ford has to say
I worked at a BMW shop once and the story BMW told my boss was that 500 miles was acceptable with a certain engine
A tight engine robs horsepower and fuel economy
And you do want some oil to get to the compression rings.

 

Trucks in the family : 3 , '00 suburban 6.0L 2500HD 4x4, '00 GMC 5.3L 2500 HD , '07 3500 6.6L Diesel 4x4.
How many see an oil level drop before or at halfway computer recommended oil change ? ALL of them.
Whoever tells you oil level should not drop at all between intervals is lying. All of them do , oil just gets " reduced " or " evaporates ". Its just normal.

 

Many makers..depending on the year..consider 1000 mi/qt acceptable consumption. An engine is not a sealed system...rings, valves, seals...all contribute to some loss

 

How many miles are on this new engine.........you might still be in the "Breakin Period" which can burn some oil until the rings are fully seated.
How much oil does it burn in 3,000 miles?

It has been a common mistake to install the rings upside down durning a re-build which will cause oil consumption.

 

Hey, thanks for everyone's responses. In answer to Mackey's question. My remanufactured engine is 9 months old with about 11,000 miles. Its is a Jasper engine, which has the best reputation.

at around the last 2000 mile interval, I added 25% of a 1 quart container of oil to bring it to correct level. I crawled underneath the truck and saw leakage where a wired sensor screws directly into the oil pan, Plus the oil pan gasket is damp, so maybe the gasket didn't set properly. From what I can see the block and valve covers look dry. It is still under the 1 year installation warranty from the mechanic who installed it.

The other thing that concerns me is the intake manifold. The intake manifold has no gasket. The mechanic had to use JB Weld because a gasket would not mate with the worn manifold surface anymore. It had a slow leak, so the mechanic re-installed the intake manifold again with fresh JB Weld at no charge. They no longer make intake manifold for my make/model anywhere.

 

How does JB Weld 'give' in the same way that a gasket can with changes in temperature, I wonder? This sounds crazy. You'd think high temp silicone would have been better than that.