2005 Impreza, Oil consumption?... 4000rpm Engine Knock?

What is your mileage between oil changes? If 7,500 then 1.0 L is not too bad. My 2.5L uses less than a measured 6 oz. per 5,000 mile oil change. I am a fairly easy driver and do not down shift to use engine braking which will increase consumption. I also broke my engine in over a few thousand miles by not jaming or babying the car.

Mine (05 OBS) but normally does not require much oil (I broke it in the way Subaru wanted: varied rpms and did not floor it for 1000 miles). When I'm beating the heck out of the engine (keeping the rpms high blasting thru a mountain range) it tends to use some oil. Yours though does not seem abnormal either. IMHO you should not need to do a warranty claim.

One thing to do is to play with oil brands and viscosity and keep oil change intervals short (under 5000 km) until you figure out how to deal with this. Adding a little bit of synthetic into the mix seems to help, but I'm not beating the engine often enough to have any statistics on this.

I do the recommended 6000km between services. Since the first oil change i've been using synthetic 5W30 or 10W30 depending whats around.

Right now i am 2000km after an oil change, and have had to add 3/4 of a Litre. At this rate i will need to add 2.25L between oil changes. I could live with being down a Litre between oil changes, but more than that seems obscene.

Hard to beleive its a Low emission vehicle when it uses so much oil.

Wish i had my '00 legacy GT, it never used a drop, and seemed alot more carefree than the impreza.

Body Roll wrote:

In my experience oil consumption is not linear. Don't assume it will be 2.25L. Measure it periodically.

I find it hard to believe that oil consumption has much to do with emissions.

RX-8 is a notorious oil eater and yet people happily add a quart every

I have 2004 Legacy with 2.5L engine, unfortunately non-turbo... It consumed 1L oil per 3000 km right from the beginning. It means that I had to add oil 4-5 times during one 15000 km service interval. Of course I wasn't too happy because I didn't want to pay that much for an oil burner.

First the dealer said that just drive few thousand kilometers and it will be ok after that. Nope, it wasn't. Then they said that FHI had informed that there are some problems with 2.5L engines, but the oil consumption should stop after 15000 km. Nope, it didn't.

After 20000 km they believed that it won't stop and they opened the engine. The cylinders were measured to be fine, so they only changed pistons and piston rings. That didn't do any good either, still steady 1L/3000 km.

After 30000 km they changed almost whole engine. Only head, valves and oil pan are still original. After that the oil consumption was reduced to a bit less that 1L per 15000 km, meaning that I can just do one service interval without adding any oil.

I'm reasonably happy now, since all this caused me only some troubles but I didn't cost me anything. They even paid for all the oil I needed to add at the beginning. Otherwise I'm very happy with my Subary.

All this happened in Helsinki, Finland.

- Jukka

Thanks Jukka, That seems to be the amount i am using after 28000km on my motor. Just over 1L per 3000km. I'm doing my best to drive the dealership crazy by stopping in and having them check the oil everytime i go by. I'd be really happy with

Now if i can only figure out why it's knocking at 4000rpm.

JF wrote:

The dealer here in Finland didn't take any responsibility about the oil consumption. They only reported my situation to the company which imports Subarus to Finland. That company then made detailed decisions what will be done. I don't know if the bill finally went to FHI in Japan or if the importer paid it. Subaru isn't too popular here and they are trying to get more market share. Maybe the importer wanted to pay the bill to maintain good reputation for Subaru. I have to admid that at one point I promised to do my best in ruining Subaru reputation if they don't fix the oil consumption... Anyway now I'm very happy both with the importer and with FHI.

I haven't noticed any knocking at any rpm.

- Jukka