Increased Oil Consumption with Extended OCI? HELP!

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RallyMachine

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Let me preface this thread by saying this is my first experience with extended oil change intervals.

I changed the oil in my modified 05 Legacy GT turbo about 4600 miles ago (recommended 3750) based on a UOA from Blackstone. The analysis was of RP 5w-30 but I have switched to Amsoil Euro Full SAPS 5w-40 (also okayed by Blackstone).

These cars are known to have oil consumption issues but within the past 1000 miles I have added about 2 quarts worth of oil. I checked my dipstick this morning and had about half on the stick...just checked it and it was below the low line. I have about a 70 mile commute round trip and do like to get on it every once in a while. I also just got back from a 300 mile round trip this past weekend.

Is this amount of oil usage normal for an extended oil change? Is the oil breaking down or what? The car was compression tested about 4 months ago and had numbers that were a bit low but still in the acceptable OEM tolerances. There is NO oil on the ground and the block and heads are dry as can be. Please help!!!
 
I will be doing a change and UOA ASAP but I am concerned that there might be an underlying problem with the oil or the engine.
 
So you changed 2 variables, the oil brand and switched to extended OCI's?

Did the oil consumption start immediately after changing oil brand or later on?
 
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Three thoughts. First is happy: pcv.

Second and third not so much. Ringland or turbo. Pull the down pipe and check turbine for play and for signs of oil. It's better to catch the turbo before it takes out the block...
 
Originally Posted By: LeakySeals
So you changed 2 variables, the oil brand and switched to extended OCI's?

Did the oil consumption start immediately after changing oil brand or later on?


Oil consumption started after about 3000-3300 miles into the oil change. I know this oil is meant for cars with minimal emission systems, but since my car is completely catless I figured I wouldn't have a problem.

Originally Posted By: 05LGTLtd
Three thoughts. First is happy: pcv.

Second and third not so much. Ringland or turbo. Pull the down pipe and check turbine for play and for signs of oil. It's better to catch the turbo before it takes out the block...


How would I go about checking this pcv valve? The car does have 75k miles but I haven't really noticed a significant decrease in power... Turbo is a VF52 with
Thanks for the thoughts guys!
 
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Follow the vent lines off the passenger side valve cover up toward the intercooler. The pcv valve is on the back passenger side of the block near the tgv stacks if I remember right. At 75k I'd just replace it as regular service. The angle and pressure fit is kinda weird for a pcv valve.

If you start to hear a noise that sounds like marbles in a blender, turn the car off immediately. Don't restart it for anything until the turbo is pulled. There have been vf-52's that have had early failures. Hopefully it's not the case here, but that much oil from a bad pcv seems out of line. Turbo is better than ring land failure.

Can you pull codes? If your seeing knock sensor repeatedly, then ring is more suspect.
 
Awesome, thank you! So I'm guessing the larger hose plugs into the inlet pipe?

Edit: I do have a scan tool, but I currently don't have a CEL. Should I check them anyway?
 
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If you have any options, I wouldn't drive the car until you can figure this out. You very well may be on the verge of something nasty here. Perhaps being dilligent in checking oil has given you the chance to avoid starting a rebuild thread on LGT.com...

If your careful you can pull the inlet tube to the turbo and check for play on the intake side. The inlet tears easy, unless you have upgraded to silicone.

Curious, mod list? Tuner?
 
Originally Posted By: RallyMachine
Awesome, thank you! So I'm guessing the larger hose plugs into the inlet pipe?

Edit: I do have a scan tool, but I currently don't have a CEL. Should I check them anyway?


Not all codes trigger a light. Sometimes they just get tucked away in the stored area.
 
No codes stored in ECU.

I'm thinking it might be the PCV valve after doing some research. I have recently began to notice a slight fluctuation/roughness at idle when cold. Possibly a combination of using a coarser oil and letting contaminates build up during the extended interval.

The car has VF52, full exhaust, K&N Typhoon, Perrin TMIC, DW 740cc injectors etc. The car was tuned by IPS motorsports by the previous owner. It's tuned very rich to prevent any knock event but I'm afraid some of it might be blowing by into the crank case. I definitely need a retune in the near future
tired.gif


I'm gonna change the oil and possibly the pcv (if I can find it at a dealership) tomorrow and hope for the best.
 
Well I got the change done and it seems like any major consumption has slowed down as I am no longer adding additional oil.

Here's the less than stellar UOA
frown.gif
I did noticed my coolant was a bit cloudy but I also saw that the RP 5w-30 that I rand before this had a decent amount of sodium in it. Thoughts on the sodium and steel levels?

05LEGACYGT-032013_zps05847c29.jpg
 
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Yeah that's what I'm concerned about...

Could the oil be shearing down since it is barely in the viscosity spec after adding 3.5 quarts in 4700miles? (Added about 2.5 quarts after 3000 miles)
 
What oil filter are you using? You may want to use OEM if not already. You can also check if your spark plugs are spec.
 
If its the first time using this oil it is common that an engine consumes some for a while. We see it very often here especially when going from conventional to synthetic.
I suggest running out the interval,the consumption should subside once the oil lays down its anti-wear layer and the engine gets accustomed to the new brand of oil.
If you look at some of our members threads you will see that when changing brands and/or grades some engines consume some oil but it does stabilize.
Keep us informed of your observations please. I'm curious to see how long before it tapers off.
 
I'm no Subie expert,
but if I were running a modified high performance engine that's also set up rich I would forget about extended OCIs.
On top of that there's more contamination from increased blow-by.
I would put in an inexpensive synthetic oil and change every 3000 miles.
 
Originally Posted By: gregoron
What oil filter are you using? You may want to use OEM if not already. You can also check if your spark plugs are spec.


I'm using an Amsoil filter, which as I understand, is better than most you can buy at an auto parts store. Plugs were replaced
Originally Posted By: Clevy
If its the first time using this oil it is common that an engine consumes some for a while. We see it very often here especially when going from conventional to synthetic.
I suggest running out the interval,the consumption should subside once the oil lays down its anti-wear layer and the engine gets accustomed to the new brand of oil.
If you look at some of our members threads you will see that when changing brands and/or grades some engines consume some oil but it does stabilize.
Keep us informed of your observations please. I'm curious to see how long before it tapers off.


Interesting, that does make sense. I guess it could also be cleaning up some sludge/gunk build-up since it's formulated to reduce soot/carbon in the engine?

Originally Posted By: circuitsmith
I'm no Subie expert,
but if I were running a modified high performance engine that's also set up rich I would forget about extended OCIs.
On top of that there's more contamination from increased blow-by.
I would put in an inexpensive synthetic oil and change every 3000 miles.


That's what I've been thinking while going through all this. Might as well just put some T6 in every 3k and know I have clean, fresh oil all the time than trying to save a few bucks with extended OCIs.
 
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Just checked my oil level and it's below the low marker with less than 600 miles on the oil! Is this oil just too thin for my application or what?!
 
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