Hi everyone,

 

my '98 subie outback has been 1 quart low on oil but with no apparent leak - no oil spots in the parking space or oil drops hangning from key areas...

 

after the last two oil changes the mechanic is reporting that it has been a quart low each time.

 

i have the oil changed around 3000-3500k. this last period i had also done a road trip of about 2000 miles, plus around town after i got back to rack up over 3000k miles between changes.

 

there's no indication of a major leak or belching blue smoke on start up.

 

what other ways could my car be using/burning oil and is this a big deal for a subie with 128k miles on it?

 

thanks!

 

gringorio

Two sources of oil consumption are valve guide seals in the heads, and oil rings on the pistons. A quart of oil every 3000 miles is very good for a 8+ year old vehicle with over 100000 miles. Have a few customers that use a quart every 1000 miles, and though it is not optimal, it is nothing to tear an engine apart over.

 

Whenever the oil is dirty, it burns. check your oil every 1000 miles (at least) and see when it is dirty (discolored), and that point it might be good to change it, old oil not only burns faster it also sticks to the wall and the valves. You may want to add some mystery marvel oil or seafoam to the vehicle, or have a throttle body cleaning, also check the PCV valve as that will cause oil consumsion and lead to a baffle plate leak if it completely goes bad.

 

Hi everyone,

 

my '98 subie outback has been 1 quart low on oil but with no apparent leak - no oil spots in the parking space or oil drops hangning from key areas...

 

after the last two oil changes the mechanic is reporting that it has been a quart low each time.

 

i have the oil changed around 3000-3500k. this last period i had also done a road trip of about 2000 miles, plus around town after i got back to rack up over 3000k miles between changes.

 

there's no indication of a major leak or belching blue smoke on start up.

 

what other ways could my car be using/burning oil and is this a big deal for a subie with 128k miles on it?

 

thanks!

 

gringorio

How old is your pcv valve?

 

nipper

Whenever the oil is dirty, it burns. check your oil every 1000 miles (at least) and see when it is dirty (discolored), and that point it might be good to change it, old oil not only burns faster it also sticks to the wall and the valves.

Modern oil contains detergents and can get "dirty" or "discolored" pretty quickly. And its no reason to change it.

I agree on PCV valve - make sure its new and genuine part. If it was bad - make sure you clean PCV hoses cause they might be clogged as well.

Hi everyone,

 

my '98 subie outback has been 1 quart low on oil but with no apparent leak - no oil spots in the parking space or oil drops hangning from key areas...

 

after the last two oil changes the mechanic is reporting that it has been a quart low each time.

 

i have the oil changed around 3000-3500k. this last period i had also done a road trip of about 2000 miles, plus around town after i got back to rack up over 3000k miles between changes.

 

there's no indication of a major leak or belching blue smoke on start up.

 

what other ways could my car be using/burning oil and is this a big deal for a subie with 128k miles on it?

 

thanks!

 

gringorio

 

I'm not sure I understand the question. You have 128K miles and use a quart evey 3000 miles or so. Have you ever had a car that did better? All car burn oil, most more then that. There's lots of ways for oil to seep past rings and valves in tiny amounts on even the best engine.

 

A good rule of thumb is ...if you can go from one oil change to the next without adding a quart, then your motor is in great shape.

at over 100,000 miles a quart every 1000 is still considered acceptable (but i wouldnt). In the winter i use a quart between oilchanges due to a problem with valve stem seals. In the warm weather i cant even track it.

ALso you may have leaks you dont know about (yet).

 

nipper