05 LGT lim. burning excessive oil?!?

[JazzAvi8r]

hi all.

 

after searching, I've come to find that these motors definitely 'use' oil, but how much is normal, and how much is too much?

 

I did an oil change less than a month ago. Mobil 1 5-30, new mobil 1 filter (not typically my preference, but it came with the oil). My wife drove it to Texas and back. yesterday, I noticed the red oil light come on for low pressure. it just flashed, it didn't stay on, but it was enough for me to want to check the oil level. not puffing blue smoke at all (or any smoke at all for that matter); no leaks to speak of, no oil puddle on my driveway. the oil was 3 quarts low!!! yeah, like moments away from being seized low.

 

any thoughts as to what might be causing this? no reduced power from what I can tell. still sounds like pretty strong compression (no I haven't ventured to run a check yet), no smoke, no leaks.

 

edit: 3250 miles since last oil change.

[SCASEYS]

really?

[JustCallMeNick]

You burned through 3 quarts in a month? That's a lot. How many miles since the oil change? Also people tend to shy away from Mobil 1 synthetic in these cars. You can find threads about it with some more googling.

[bluesuby]

I have used Mobil 1 (Extended Performance) since day1 and have 160,000 miles on the clock. No measurable consumption with around 2500 miles between changes. I wonder if a bad break-in was responsible.

[MilesA]

It's a good idea to check the oil level at least every other time you fill the gas tank. You can't go by the oil pressure light, it won't alert you until you are in the danger zone.

 

If your turbo has high miles, you can be losing oil past the seals. Going high speeds for long distances, frequent engine braking, full throttle acceleration, bad PCV are some things that can bring about higher oil consumption. Bad rings, too, of course, but it doesn't sound like your car has that issue.

[GTEASER]

Stay away from Mobil Juan. The van rides are sketchy and can lead to butthurt.

[FJuan]

Mobile Juan reporting.

[JazzAvi8r]

good to know. what is the preffered oil?

 

no engine braking, I have the 5EAT. I don't abuse the car and neither does my wife (she claims it's her car). I doubt it's the turbo seals since there's no smoke to speak of -- no catch can either so any blow by coming from the turbo is either getting stuck in the mishimoto TMIC, or getting consumed by the engine. same for the rings. seriously doubt that's the cause. I'll check in to the PCV though. that's one I hadn't considered. yet

 

thanks

[FJuan]

A lot of us use Rotella T6 or Castrol Syn, both these oils have been proven to have the right amount of minerals in the oil that our turbo needs to stay healthy.

[SCASEYS]

Rotella and Motul will be the hypetrain leaders

I like Pennzoil myself

[GTEASER]

I use strictly Castol Edge 5W-30 in my Subaru turbos. Never had any oil consumption and always fantastic UOAs.

[JazzAvi8r]

thanks for the insight. I wont make that mistake again. I'll roll with Castrol Syn next. Should I stick with the 5-30? or go with something a bit more viscous? I'm in Colorado and winter is coming (pun intended), so not too sure if I want to venture in to the 10-40 range.

[GTEASER]

How many miles are currently on the motor?

[JazzAvi8r]

good question.

195k on the chassis.

 

block was rebuilt by Subaru under warranty at ~35k. head gaskets, water pump, timing belt, etc. redone about 140k.

[MilesA]

If you have the original turbo at 195K, it is past time for a rebuild or a new one. You can have oil getting past the seals without leaving visible smoke trails. Your catalytic converter(s) can prevent it.

[JazzAvi8r]

oh goody!! perfect excuse to go to the vf52.

 

doing a bit more research, I'm going to buy a few oil filters.

 

Mazda N3R1-14-302 RX8 Oil filter 09-12. $6.75/ea. these are the preferred ones, correct?

[JazzAvi8r]

Also, I plan on putting in an aftermarket up-pipe to replace the stocker with the cat in it. If the turbo truly is on its way out, this should help reveal that issue. also debating if I want to replace the downpipe and go catless to mate up to the Borla. i'll need a tune after that, though.

[sigmafour]

Uppipe not known for great revelations... downpipe off at least gives you access to check for some shaft play.

[JazzAvi8r]

I was under the impression that the stock UP is problematic for the turbos. something like baffle material or fragments from the cat get sucked up into the turbo and destroy it. that's why I want to swap it out for either an aftermarket version or the STi one. as a previous poster mentioned, if the cat is hiding the smoke from the blow-by, deleting that cat may yield some smoke out of the exhaust. that's what I was referring to.

[MilesA]

I was under the impression that the stock UP is problematic for the turbos. something like baffle material or fragments from the cat get sucked up into the turbo and destroy it. that's why I want to swap it out for either an aftermarket version or the STi one. as a previous poster mentioned, if the cat is hiding the smoke from the blow-by, deleting that cat may yield some smoke out of the exhaust. that's what I was referring to.

You have to remove the downpipe anyway to do the uppipe replacement. It's like a jigsaw puzzle in there.

[JazzAvi8r]

good to know. thanks. I'm seriously debating doing both the UP and DP at the same time, then doing a stage 2 flash or custom dyno tune. haven't quite decided yet.