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Turbo blowing oil through intercooler?

29K views 105 replies 9 participants last post by  ic3b3rg 
#1 · (Edited)
I just traded in my beater '06 Honda Accord for a '12 WRX with about 75,000 miles on it. Luckily I bought the biggest, baddest warranty I could from the Toyota dealership that had it for sale because my local Subaru dealer found some problems...

The Toyota dealer claimed that the car had "undergone a 140 point inspection" and was caught up on maintenance and "100% stock". On the test drive I noticed the exhaust didn't sound stock. When I mentioned it the salesman assured me that it was and that's just "how the WRX sounds". The only reference I had was my buddies STI with an after-market exhaust so I believed him. I had my uncle (a mechanic that works on buses) look over it with me and everything seemed to be in good shape. Brand new tires and breaks; nearly complete service history; new clutch; hoses weren't brittle; etc.

After driving it around conservatively for about 200 miles I decided to really get on it on a highway ramp and heard a hissing or "whooshing" sound that I've never heard in any car, turbo or otherwise before (buddy has an STI, brother drives a SAAB 900 turbo).

So when I got home I took a look at the air filter. It looked like it had been gummed up with tree sap and road tar or something... Not what I would call caught up on maintenance. I did nearly all the maintenance on my Honda so I went about the basics on the WRX. I jacked it up and did an oil and oil filter change. The oil didn't look excessively dark or anything. The exhaust definitely did not look stock. The mufflers were removed but it looked like the cat and the resonator were still intact. Went to remove the spark plugs and... lets just say I rage quit.

Even with the air filter replaced the whooshing sound didn't go away so I took it to my local Subaru dealer thinking I had some kind of vacuum/boost leak.

I had them inspect everything and they found that, besides the exhaust, I also had a performance clutch and a kart-boy short-shift kit installed by the previous owner. I wonder if I could sue for false advertising or something - anyway, the downside was that they found a oil on the hose leading away from the intercooler leading them to believe that the turbo is passing on oil through the intercooler - most likely meaning I had a leaking seal and would require the turbo to be replaced. The hose clamp was essentially spinning freely from the oil. They think the sound I'm hearing is boost leak from that.

I invoked my warranty and the Subaru dealer is going to do the work next week.

My question is:

Is it actually safe to be driving around in this condition? The Subaru dealer didn't make it seem like a big deal at all. They told me "the engine will just burn the oil, you may smell it - keep an eye on the oil level." He told me not to even worry about driving it hard?! At the least I'm pumping oil into my intake, at most I could blow my turbo, right? If I break the turbo and send bits of metal through the entire engine... :mad:

I'm already driving very softly (trying to keep it under 3500RPM) but should I quit driving it altogether until fixed? Once the new turbo is in is there anything I can do to flush the intake out or will it just suck everything through and sort itself out? Anyone have anything like this happen to them before?
 
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#2 ·
Sorry to hear your already jumping through hoops with your new car.

Anyway to answer your question and give you a bit of knowledge here goes. The condition your talking about is called blow by.It is a normal condition as the seals in the turbo wear but the ammount of oil that is blown by is the issue. The reason it can be dangerous for your car is because oil in your intake path means that the engine is getting a more knock prone fuel/air mixture. Assuming everything is stock ( which we now know it is not ) and assuming you have a stock tune you should be fine running with some minor blow by as long as you are not stomping on the throttle. The issues tend to start when you have more major leaks and your engine starts knocking becaues of the poor fuel air mix quality.

In the future you can help negate the possible harm to your car by installing an Oil Catch can ( which helps remove oil from your vac lines ) as well as runing the best quality fuel you can find. Fuel with a higher than 91octane rating will help negate some of the octane lowering going on with the blow by.

As far as a toyota dealership telling you everything is covered thats great. I would also have the subaru dealership return the exhaust to stock and reset the ECU to stock. In many cases drivers add aftermarket exhausts including downpipes that require the ECU to be retuned. When non Subaru techs return them to stock they can miss the aftermarket parts and or miss the retune leaving you with a dangerous tune or dangerous parts on your stock tune. Long story short I would talk to both dealerships and get your car reset to stock correctly by a Subaru mechanic. If toyota is willing to foot the bill thats even better.

Hope that helps
 
#3 · (Edited)
Thanks for the quick reply! So it sounds like I really just need to be listening for the engine to start knocking - as that would mean the leak is getting worse and I should stop driving it at that point, correct? The work is being done in 3 days, so I'm thinking I'll probably be fine until then.

I was already considering an oil catch can - thanks for bringing that up. Would you recommend that over some type of air/oil separator (so I don't have to remember to drain the can, haha)?

I'll make sure the Subaru tech flashes the ECU back to stock - if the exhaust has only been modified from the cat (or even just axel?) back would it require a re-tune over stock? I don't mind that it is a little louder, I just would like to run on the stock tune.

It looks like the downpipe/cat/resonator are still stock (just going off of pictures I found online). It really just looks like a "muffler delete" or whatever they call it when they go straight-pipe from the resonator back.

Thanks again for the wisdom!
 
#4 ·
Almost,

Once you hear it knocking youve already caused the damage. the idea is not to cause that damage in the first place. Nice quality high octane fuel and driving like a grandma would both help keep the knock from happening in the first place. Honestly if you can afford not to drive it for the time being i would choose that option.

A separator is a good call if only because the amintnence is less and I think grimmspeed makes one that just drains right back into the oil inlet as well. The downside of a no maintenence unit is that you dont get to keep tabs on how much oil is actually being removed from the path. Thats a good meter to see how your engine is doing.

If the exhaust has been modified before the midpipe then you should get a stock unit or a custom tune to handle the new exhaust. Pretty much the rule of thumb is if you change the intake or exhaust path at all you tune. You can get away with an axlback system without a tune but most full catback systems change the exhaust flow in a meaningful enough way to warrant a tune.
 
#6 · (Edited)
Steady diet of 93 - check
Granny driving - check

It can get fairly cold in Ohio. I live in Cincinnati (not that bad) but go to Cleveland occasionally for work and it routinely hovers around 0F/-18C for weeks at a time during the winter but usually isn't much colder than -10F/-23C.

It sounds like the catch can is the route I will go. I'll also have the Subaru tech take a close look at the exhaust and let me know where it has been modified. Hopefully just axle back. In that case I'll make sure the computer gets set back to stock.

Can anyone recommend their favorite catch-can system and/or other reliability and longevity mods?
 
#7 ·
I have a ebay special Oil catch can on my car. It does the job an was only $20! If you want to pay for a name then go with one of the big companies... but I promise you it is unneeded. You don't want a AOS where you live.

I check my catch can and empty it every week. Being in the cold climate it will look milky but that's because we get a lot of condensation where its cold. That's why we can't have the AOS.

Then just drive knowing all that crap is staying out of your piping, turbo an intercooler.
 
#8 ·
yea catch cans and AOS's are quite different.

catch cans work great but require almost weekly maintenance in some cars.

the IAG AOS heats the unit and the oil using the engine coolant so theres no condensation. its expensive yes, you could probably buy 10 catch cans for the price, but the trade off is 100% maintenance free and the oil drains back into your crankcase, even in cold climates.

if you dont mind checking/draining often, then a catch can will be fine. i should also say the maintenance shechdule is dependant on the size of the can. smaller ones need to be checked weekly, larger ones u can probably check monthly or with every oil change.
 
#9 ·
How difficult is it to drain the catch cans? The type I've seen just browsing around look like they all drain from the bottom. Obviously it is going to depend on where I put it in the engine bay, but do people typically get under the car and drain them almost how you would drain oil from the oil pan? Could you take them off the mounting bracket and just dump it in some kind of cup, etc., without having to get under the car? Do most people just pour the accumulated oil back into the engine or get rid of it?
 
#10 ·
I use a syringe and pop off the little hoses on the side that tell you how full they are. Connect the syrindge to that and suck out all the shiznit out. Super simple and no removing or getting under the car.

When you have a catch can it is going to be milky like I said before. That means this oil is no good. Just dispose of it.
 
#11 ·
Yeah if you use something like a wing nut to hold the catch can on the brackets you could easily turn it off and dump it into a cup. Just be careful not to dump any oil back into the vac lines, kinda negates the purpose if you know what i mean.
 
#16 ·
Aside from my hippy EPA concerns and my burning anger if you ever visit a track and spray your oil blow by all over my clean asphalt, you will have vacuum issues venting it out a hole like that unless you install a pair of check valves on the bottom of the can. In which case you might as well throw a brass fitting on the end of a hose from the bottom and just drain it when you swap oil.

In fact theres an idea, Tap the bottom of the catch can and run a fuel line ( or other oil safe line ) down the side of your engine bay and add a brass valve to the end so you can easily drain the catch can whenever you are under the car. No disassembly or removal of the can.
 
#22 ·
It turns out that it isn't my turbo leaking oil. They have no idea what is so they are taking my entire engine apart looking for the leak. They even sent the head off to a machine shop to see if anything is wrong with it. I did manage to snag some pictures of the engine while I was talking to the tech.
 

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#23 ·
wait... wait... is this a Subaru dealership?

I mean there is Blow by oil that does not come from the turbo but comes from the crankcase and valve cover breathers which is where you hook in the catch can into. The oil would actual come through the turbo inlet, into the turbo and then typically get caught up in your top mount intercooler. But what does go through your motor will get burned up and make you pistons look like what I see there an make your plugs look shitty.
 
#24 ·
Yes, this is a Subaru dealership that is working on the car. Purchased from a Toyota dealership. My original symptom was oil on the outside of the pipe leading away from the intercooler to the throttle. Their original thought was that it was blow-by from "leaking turbo seals." They have taken the engine completely apart and found that it had nothing to do with the turbo - so now they're trying to figure out the problem that would cause so much excess oil and air to be going through the crankcase and valve cover breathers, into my intake and leaking out near the exit of the intercooler.

The catch-can discussion was just kind of a digression about "reliability mods" for after I get a car back - not as a solution to my current problem.

The car has been in the shop for 7 days now and is going to cost me about $1500 plus the deductible on my warranty (~$200). After all of that is said and done I still paid slightly below KBB value, so I really can't complain too much.
 
#25 ·
If the car had ever been tuned for more boost (and even if it wasn't) that would cause more blow by. My car had a ton of it!

If the turbo inlet is stock it wouldn't surprise me if you were getting a lot of blow by also. Hell even if it is aftermarket as well. But the OEM is more restrictive so it would pull air from the path of resistance.

But think of it like this. Your system right now has the crankcase and valve cover vents routed back into the turbo inlet to get "burned off". The Turbo inlet creates a Constant vacuum pulling air into the turbo. When you get on it an boost the turbo is pulling in a lot of air as well as creating more positive pressure in the crankcase an in the heads. That means you have an extreme high chance to pull in crap. Subaru's are known for excessive oil blow by. Some are better than others but some are bad just because it what makes Subaru a subaru.

Now with a catch can you don't have any of the above issues. You have no forced vacuum in the valve covers an crankcase pulling out the crap and into the turbo inlet. Now instead your crankcase an valve covers are just releasing whatever pressure or crap it has as it has it. Better burn and 0 blow by.

Im telling you these guys are wasting there time. Clamps just weren't tightened and the blow by was leaking out.
 
#26 ·
So you think my problem is just my Subaru being a Subaru and the catch can would solve all of the problems? You don't think it's worth the money to have them investigate why there is so much blow by? I think it's too late to tell them to stop working on it, haha, but that's good to know. I'm definitely going to add a catch can when all of this is said and done.

They also keep trying to sell me on a fuel system cleaning to get rid of all the carbon on the injectors, cylinder heads, valves, etc. If it's not dirty fuel causing all of that gunk, would fixing the blow by problem mean all this stuff will clean itself out once it's not burning so much oil any more?

Should I just buy fuel additive and do it myself instead of being charged $150 to have them do that. They did say the would put the injectors in an ultra-sonic cleaner and clean out the intake and throttle, etc. which I wouldn't be able to do (at least the ultra-sonic cleaner part).
 
#27 ·
This crud is from oil not fuel IMO. The oil is causing a bad burn.

It has nothing to do with your injectors. That is just ridiculous. If you were getting over fueling issues or misfires or running lean an everything else checked out then yeah sure.

I feel pretty strongly that these guys are just idiots... I have found that with a lot of dealerships. Typically its performance shops you want to go to. Subaru wants OEM an sadly its the OEM system causing this problem.

On top of the catch can install a wideband o2 sensor to keep an eye on everything. Its worth it. I love the cobb access port for being able to watch the vitals but a wideband will always be more accurate then the narrowband on the car itself.
 
#29 ·
I feel pretty strongly that these guys are just idiots... I have found that with a lot of dealerships. Typically its performance shops you want to go to. Subaru wants OEM an sadly its the OEM system causing this problem.
This, so much this. Ive used performance shops for most of my maintenence and ive never had the issues that dealerships have given me.

Also in a previous post you noted that this was costing you money? I get the deductable on your warranty but why the other $1500? If its at all possible i would push to have the whole job covered under your warranty especially if they cant resolve the oil blow by issues.
 
#28 ·
Yeah, they've had my car for 14 days now, I'm starting to think they either don't care or are incompetent. Nobody can give me a reason why it's taking so long. My mechanic buddy said that it is most likely an 8-10 hour job. So I'm thinking 3 or 4 days, right? Assuming they have to work on other vehicles, etc.

Yesterday I called for an update and they said that "the tech that was working on your car is out sick and your service manager had a scheduled day off." When I asked what that meant he told me "nobody is going to be working on your car today and I don't have any information to give you as far as a status update, I'll have someone call you tomorrow with more information." I thought that was pretty pathetic customer service.

They did finally agree to lend me a Forester XT with less than 50 miles on it that I've been driving around. It's pretty nice - the wife wants one now - but I'd still rather just have this whole thing behind me.
 
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