Unknown source of leak on engine

[Wardog692]

I've noticed some staining on my engine block, seemingly from oil. I'm trying to at least narrow down where it might be coming from before I have to take it in to the shop. I know it's on the passenger back corner, and relatively deep down in the engine bay. It just seems to be seeping, not dripping, and I don't have any warnings or CELs and it doesn't leave a puddle. Hard to tell from pics, I apologize as it's deep in the engine bay.

The area in question:

Better spotlighting, it's just in line with the two white bolts:

Close up:

Edit: Additional photos of drivers rear corner/below rear BOV

[SHOdded]

Unlikely that it is the valve cover statistically, the Gen 4.1 has not had issues with valve cover gaskets as much as the Gen 4.2 (still not that much) which is typically in the area of cylinder 3, bank 1.

Have you taken the cover off to investigate further?  Are the PVC valve & piping clean?  If not that, then I would turn to possible turbo related leak from either a split/loose pipe there or an oil feed line that has just begun to leak, blowing up into the engine bay.

[Wardog692]

Update, did some more investigating. I'm VTA, and it looks like my rear BOV is spraying oil across the back of my engine bay. Added pics in the original post.
I was already planning on taking it in, but how much should I put back stock before I do? Only VTA and intake done so far. Still under 10y/100k mi powertrain warranty.

[MiWiAu]

Update, did some more investigating. I'm VTA, and it looks like my rear BOV is spraying oil across the back of my engine bay. Added pics in the original post.
I was already planning on taking it in, but how much should I put back stock before I do? Only VTA and intake done so far. Still under 10y/100k mi powertrain warranty.

How many miles on the car? Have you ever checked any of the intake plumbing or intercooler for oil? You could pull the hose to the throttle body and check for oil, or pull the MAP sensor on top of the IM.

I had oil in my XSport, but cleaned it out and installed an OCC and CSS and haven't had an issue since. If there's oil in the intake plumbing or charge pipes, not surprising it's spraying a bit from the BOV.


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[Wardog692]

Update, did some more investigating. I'm VTA, and it looks like my rear BOV is spraying oil across the back of my engine bay. Added pics in the original post.
I was already planning on taking it in, but how much should I put back stock before I do? Only VTA and intake done so far. Still under 10y/100k mi powertrain warranty.

How many miles on the car? Have you ever checked any of the intake plumbing or intercooler for oil? You could pull the hose to the throttle body and check for oil, or pull the MAP sensor on top of the IM.

I had oil in my XSport, but cleaned it out and installed an OCC and CSS and haven't had an issue since. If there's oil in the intake plumbing or charge pipes, not surprising it's spraying a bit from the BOV.


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I've got around 86k, but I just got it a little under a year ago. Haven't really checked anywhere else, but there was quite the pool under the BOV that I don't recall seeing when I bought it or any other time I've been under the hood (although I wasn't really looking for it either).
I have had zero driveability issues, which I find surprising if a turbo is truly gone. No CEL/lights, no lack of power/hesitation. I've even done some "spirited driving" and nothing seemed wrong. Now I'm almost scared to drive the thing...

[MiWiAu]

I don't want to go so far as to say what you're seeing is "normal", but I don't think it's a stretch to say that it's not uncommon.

I had so much in my intake that it was dripping out around the throttle body and pooling around the front valve cover bolts. This was at 29k miles!

After cleaning everything out, I've had no issues over the last 8k miles. I'm VTA as well and have no spray from my BOVs.

Problem is, once you get a little oil in the charge pipes, it will continue to circulate from charge pipe to intake pipe until some eventually is released from the BOV or it makes it all the way to the intercooler or IM.

I wouldn't worry TOO much, but it couldn't hurt to have it checked out and cleaned.

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[SHOdded]

Doesnt look significant to me either, mayhaps benefit from periodic intercooler cleaning.

[glock-coma]

I had the same type of oil mist after I went vta.
I haven't noticed anymore since I cleaned it the first time.

[Wardog692]

I had the same type of oil mist after I went vta.
I haven't noticed anymore since I cleaned it the first time.

I understand the mist, it's the puddle in the 4th picture and the seeping leak in the first picture that are more worrying.

[MiWiAu]

I had the same type of oil mist after I went vta.
I haven't noticed anymore since I cleaned it the first time.

I understand the mist, it's the puddle in the 4th picture and the seeping leak in the first picture that are more worrying.

Not sure about the seep in your first pic, but the 4th pic is below the rear BOV, correct?

If so, whatever oil mist doesn't completely exit the BOV will collect in the outlet and eventually coalesce enough to drip out, which could explain the collection below the rear BOV.


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[Wardog692]

I had the same type of oil mist after I went vta.
I haven't noticed anymore since I cleaned it the first time.

I understand the mist, it's the puddle in the 4th picture and the seeping leak in the first picture that are more worrying.

Not sure about the seep in your first pic, but the 4th pic is below the rear BOV, correct?

If so, whatever oil mist doesn't completely exit the BOV will collect in the outlet and eventually coalesce enough to drip out, which could explain the collection below the rear BOV.

Yes it is directly below the BOV, and that was my guess as well, it just seems like quite a lot of volume of oil which I guess was my worry. I went VTA back in the summer, so I guess it's about 6 months worth of oil collection there that went unnoticed.

Thanks for all the help so far guys! I'm taking it in on Monday to get it all checked out anyways (I've got some other issues like blend door actuators and a CV axle leaking as well).

For future reference, how exactly would one go about cleaning out all this oil in the piping? What parts to clean/what to clean it with/etc.? Obviously I'm no mechanic, so explain it to me like I'm Jeremy Clarkson (except that I actually care about how it works and want to learn).

[MiWiAu]

Here's a pic from my OCC install thread. This was about 29,000 mi worth of 100% OE setup. So much oil in the system that it was seeping out around the throttle body connection. I cleaned everything, did VTA, and installed the OCC all at the same time, and have had no evidence since of oil where it isn't supposed to be.



A full cleaning would require hose/plumbing removal from the throttle body to the turbos and suctioning or back flushing the intercooler to remove any buildup. I flushed my pipes and CAC with Simple Green and thoroughly dried everything before reassembling.

If nobody posts it sooner, there is a good thread on CAC cleaning on here somewhere. I can search and find the link when I get home from work tonight.

The intake piping is relatively straight forward, just tedious and time consuming (more so for the rear turbo connections). Just start removing hose clamps and tubes, flush (after removing sensors/BOVs), dry, and reinstall - preferably the same way they came out LOL.

EDIT: In retrospect, perhaps my image should read "Why install a CSS?" instead of OCC, since I'm fairly certain the primary source of oil in my intake/charge piping was coming from the OE clean side intake connection. Unless I'm missing something, the only two possible sources of oil in the intake are from turbo blow by or the cleanside intake connection. IMHO, if your turbos are in good serviceable condition, breaking the connection between the cleanside port and the intake (via CSS or alternate venting) is the best way to prevent oil from being reintroduced to the intake once you clean everything out. If this connection is removed, and you are still seeing oil, it would point to the turbos as the source.


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[SHOdded]

How to drain your CAC (Intercooler) with out taking it out
http://www.ecoboostperformanceforum.com/index.php/topic,3056

[Wardog692]

Looks like I've got some more investigating to do when I get home from work! I'll definitely be checking the CAC for oil and cleaning what I can from the pipes with a microfiber cloth. I don't have any kind of vacuum/suction pump to pump out the oil I find, so I might have to look into that. I assume I could also use the same suction pump to drain/refill the PTU? I haven't been able to find a shop in Charlotte that's willing to do that for me.

[MiWiAu]

I assume I could also use the same suction pump to drain/refill the PTU?

I don't see why not. The thread that SHOdded linked has a few variations on the process. Also a tip to use the dipstick to see if there's anything in there.

I opted to back flush mine with simple green, but I have a Master Blaster dryer that blows filtered warm air, so I let that run for a couple hours to dry everything out. My process is outlined in that thread somewhere deeper in.

Suction should get most of the junk out. If you go the suction route, jack up the drivers side or drive it up on a ramp (or park on a slope passenger side down) to allow more gunk to drain toward the passenger side. If you have the time, I'd let it set like that for an hour or so to allow time for the junk to pool before sucking it out.



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