excessive oil consumption

katnip

the car is black. I swear
04 sti 94K on the clock. using only synthetic oil. 0-30 Amsoil or 5-30 Valvoline. no smoke, not leaking or my pink skid plate wouldn't still be pink. recently changed the PCV. didn't help. up to 4 quarts a month depending on the mileage I put on. thoughts?!

 
Could be rings, could be turbo. Are you sure you aren't seeing any smoke on decel or acceleration? What about on start up?

Compression test ASAP. I would pull the DP off too and check for oil.

 
car runs great. it does have a surging issue, the PVC cured it for about 48 hours, then back to surging again.

 
many many turbo cars come by my way with stuck rings, busted ring lands, oil being shot out the turbo. Also might have to do a thorough search for a small vacuum leak causing the surging and disrupting your PCV system. DO you have codes like P0171? Fuel System lean bank 1?

 
ryan, you had busted ringlands on 4 like me right? what she has doesn't really seem like what I had anyways, and I had about 30-40 psi compression in that cylinder.

no loss of power but huge loss of oil make me think it isn't a broken or cracked ringland...

 
Nope. After everything was said and done, what killed my last motor ended up being worn cylinder walls. The machine shop found some dirt/grit in the oil passages and it basically destroyed the walls. It was not a ringland issue. I also think the way it was broken in had something to do with it's downfall.

 
many many turbo cars come by my way with stuck rings, busted ring lands, oil being shot out the turbo. Also might have to do a thorough search for a small vacuum leak causing the surging and disrupting your PCV system. DO you have codes like P0171? Fuel System lean bank 1?
no codes. I had the intercooler and all lines off while replacing the blasted PCV because it is a friken basterd to get at so I hope I would have noticed a line not attached during reassembly. it stopped the surge for a day or two once the new one was on, but went right back to low idle and surging. could a ram air cause the surge? suspect the turbo is the culprit on the oil consumption, just wanted some other opinions

oh. and whats the recommended time belt replacement mileage? I gots almost 95k on the clock, must be getting close

 
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my dads wrx is doing the exact same thing, replaced the PCV valve and it fixed it for a day or two, then it went right back into smoking and using oil! id be interested to see what you issue is because we have not had time to look into his

 
Pretty sure the Owners manual to my 2009 WRX says to replace the timing belt every 60,000 miles.
The 04 STI timing belt change interval is 105k miles, but I would do it far before then just for safety's sake.

Kat - definitely pop the intercooler off and see if oil dumps out of it. Also pull your spark plugs and see if they look ashy or if one in particular does. If none of the above, the turbo could be dumping it out the exhaust side.

How much oil (qts) would you say you loose in 100miles?

Being an internet mechanic is fun
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The 04 STI timing belt change interval is 105k miles, but I would do it far before then just for safety's sake.

Kat - definitely pop the intercooler off and see if oil dumps out of it. Also pull your spark plugs and see if they look ashy or if one in particular does. If none of the above, the turbo could be dumping it out the exhaust side.

How much oil (qts) would you say you loose in 100miles?

Being an internet mechanic is fun
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a quart atleast every 1000 miles or so. pretty much once a month or more!

 
Kat, just feed the habit until the price of oil outweighs the price of a subie motor job.

My old 911 drank a quart every 500 or so (or more accurately, smoked a quart), and the universal advice was, "oil is waaay cheaper than Porsche parts!"

 
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My '03 WRX goes through about a quart every thousand miles. Doesn't leak a drop, and the inter cooler and turbo are clean. I read some where online a while ago that Subaru considers up to a quart every thousand miles to be on the high end of normal, although it sounds like BS to me. Any way, mike and I pulled the plugs and did a leak down test, #4 looses pressure, and the plug was COVERED in ash.....I would bet that is what you are going to find....

 
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