Oil consumption and running rich?

[sprbxr]

My Subarus are officially driving me nuts. Finally got the LGT running right then the Outback starts giving me trouble. Anyway, my 98 Outback is using alot of oil. It doesn't smoke. The exhaust has a tremendous amount of soot in it. I am not getting any CEL or other warning lights. It kind of smells funny while running. Not a burning oil smell but more of a running rich smell. My mileage hasn't varied at all. BTW, it is not leaking oil and it isn't throwing any codes.

Any ideas?
Justin

[nipper]

So how ancient is your PCV Valve?

nipper

[99gtlimited]

doesn't make sense that the car would run rich and there would be no change in mileage, you should be getting worse mileage if your car has a rich a/f ratio

[nipper]

doesn't make sense that the car would run rich and there would be no change in mileage, you should be getting worse mileage if your car has a rich a/f ratio


Could be hes confusing runing rich with burning oil?

How many miles on this ?

[sprbxr]

135k on it. I guess it could be burning it although there is zero smoke. The exhaust is showing alot of black soot. I am getting 350miles+per tank. This is alto better than my LGT.

Justin

[nipper]

Change the PCV valve. Also look under the engine to see if you have any leaks.

nipper

[99gtlimited]

so the car is getting pretty good mileage, and your only problem is that your using oil?

How fast are you losing it? how many quarts to a tank do you lose?

Soot in the exhaust is not really a big deal, since burning gas/diesel creates soot naturally. After 135k your stock exhaust would be pretty full of it, especially your catyltic converters.

Are you the original owner? any previous issues with this motor?

ideas:
-Check for leaks (valve covers, front and rear seals, oil pan, etc.)
-Change the PCV valve (pretty easy and only like $5)

[sprbxr]

The oil is definately not leaking out. Do you think the PCV valve is alowing too much crankcase pressure to build up? I pulled the PCV valve and the valve and mounting are was pretty gunked up. I bench tested the valve after cleaning it and it seems to open an close w/ vacuum. Where can I get a PCV valve for $5?

Justin

[nipper]

Any autoparts store will have the PCV valve, they really should be changed once a year.

Also check the hoses attached to the PCV valve, as they can get gunked up too.

http://en.wikipedia.org/wiki/PCV_valve

nipper