Motor burns oil only at low rpms....

[GreenBird]

like, below 1000rpms. I've adjusted my driving style, but obviously something isn't right. I think it may be due to low oil pressure, caused by a very old oil pump? bearings with too much clearence?

I run 10w-30 Castrol GTX. I am using the FL-1A filter. Motor has 170K miles on it.

 

[Machspeed]

How do you knw its only at low rpms? Oil pumps rarley fail. Do you see smoke coming out of the engine? I remeber when my car burned oil from the front and rear seals you could only tell while the car was stopped.

 

[GreenBird]

When I bought the car both front and rear main seal were leaking. I replaced both.

Yes, despite having stock cats, you can see smoke, and lots of it.

It's not because I'm leaving from idle either, I can lug the engine down from speed and it'll puff blue smoke.

I think it only happens at low rpm because since I've adjusted my driving style, I burned about 1/2 a qt in 3000 miles compared to a quart every 500 miles.

 

[JaySHOguy]

Valve seals maybe? I know my car burns a little oil too. Mostly on cold start-up after its been sitting for a couple of days.

I also switched to a thicker oil. Right now, I am using Pennzoil 10W-30 for HIGH-MILEAGE vehicles.
When I was using Castrol GTX 10W-30, my oil consumption was much greater.
Of course, now that I have changed the front main seal, my oil loss has gone down a little.
Now I am using about 1 quart to every 1,000 miles it seems, rather than the 1 quart to 500-600 I was getting.