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Discussion Starter · #1 ·
Hi all.

This is a plain jane Outback 4 cyl with 164K miles on it. I've been living, as so many before me have, the burning-oil-smell-at-the-stop-light life for the past two or three years. Now, I've moved on to the apparent next phase: it's leaking oil at a significant rate. I leave a pancake sized oil puddle wherever I stop and god knows how much else flies out while under way. The entire front half of the undercarriage from the oil pan back is oil-soaked and even my ball and hitch is covered with a sooty oil residue.

It is very difficult to pinpoint the source as there's oil all over the place. I can say that it seems to be coming from the area of the passenger side and toward the back of the engine. The timing belt area looks pretty clean and dry.

Armed with that information, I spent some time replacing the valve cover gasket and spark plug grommets. The spark plug holes were filled with oil, which gave me an ah-ha! sort of feeling. Upon buttoning everything back up I took it for a drive and found upon arriving home that the oil was dripping just as it had been. It actually drips from that protective piece of steel that is bolted just aft of the oil pan.

So I'm gathering from searching here and elsewhere that the next most common culprit would be the head gasket. I'm going to try to degrease the engine and try to get a view of that back corner of the head (not easy).

Any advice or comments appreciated. BTW, I'd probably do the head gasket myself as the timing belt is due for a change.

-Jim
 

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(formerly) 03 H6 OBW , (presently) 06 WRX Sportwagon & 2021 Honda CR-V
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very rare on an 07 but, there's 3 possible sources, I think, for oil from the back of the engine; air/oil separator platecommon on older soobs with plastic plates), rear main seal(not common); and, I THINK, a wrist pin access plug(I don't see how this could leak as much as you report)?

all 3 require pulling the engine.

it's theoretically possible for a clogged/gummy PCV valve/system to make a leak worse. Honestly, we suggest it a lot but get no responses to it being helpful. But, easy/cheap to do.
 

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Discussion Starter · #3 ·
Thanks for the feedback. The probabilities are most helpful.

Though the oil is well distributed down below, there is a fresh patina up around the rear passenger side head but not the driver's side head (as far as I can see). So I'm "hopeful" that it's the head gasket.

-Jim
 

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Is the oil running down the back of the right side of the engine? Is there oil on the top of the engine at the back? There's two places in that area where oil could escape in fairly large amounts:

The Variable Valve Lift oil pressure sensor has been one source in a fair number of threads here.



Also in that area, the housing on the back of the head that the solenoid is mounted on can leak at its joint with the head, although this is less common.

Another source is the oil supply line between the block and the right side head. It's at the top of the engine forward of the area in the above photo. Here's a thread that's about that problem: http://www.subaruoutback.org/forums...e/112770-oil-leak-07-outback-wagon-2-5-a.html In that case, it is the head gasket.

Have a look, let us know.
 

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Discussion Starter · #7 ·
So just to be sure, I wiped down the oil pressure switch and then wrapped it in a paper towel. I then drove around the neighborhood a bit -- not too fast so as to minimize any wind effects. Here's the before and after. So that's a cheap first (well, second) fix. I'll repost on how well that works.

-Jim
 

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o-rings? Not there.

If the pressure sensor was oil free after the clean up, and the oil on it is all new, that's definitely going to lead oil pooling in the top area and running down the back. I'm looking specifically at the oil around the upper part of the sensor, which would not likely be that wet if the leak was somewhere else. The white part at the top is actually the wiring harness connector that fits down on the sensor. There's a single contact inside. If the white connector is taken off, you might find the area of contact in the top of the sensor full of oil. This would provide a confirmation of the leaking sensor, in this case out the top where the contact comes through. This is not uncommon. (Note: It does look as if the sensor is leaking, but that might not be the only source. At this point, if there's no other signs of oil leaking, deal with this and see if that cures it.)

Presuming the sensor is the source, it can be replaced fairly easily and it's not all that expensive, even from a dealer; however, there's a very serious caution to add. The sensor has a slightly tapered thread. The deeper it goes, the wider it gets. It screws into the top of the head in a slightly raised area of the casting. (This is visible in your first photo.) Turn it in too far/too tight, and the casting in that area can crack, and that could mean a new head. It's happened:

http://www.subaruoutback.org/forums/66-problems-maintenance/45237-just-messed-up-big-crap.html
http://www.subaruoutback.org/forums/61-general-discussions/119009-fix-head-gasket-sell.html

Confirm, decide on next step, and let us know.
 

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So just to be sure, I wiped down the oil pressure switch and then wrapped it in a paper towel. I then drove around the neighborhood a bit -- not too fast so as to minimize any wind effects. Here's the before and after. So that's a cheap first (well, second) fix. I'll repost on how well that works.

-Jim
If there's oil in the top of the sensor, when the white connector is removed, I would be surprised that the CEL hasn't been turned on by a fault detected in the VVL system. The oil inside the upper part of the sensor would coat the internal switch contacts of the sensor, preventing them from making a good contact. A bad contact can well lead to a code, in this case, P0026. Perhaps it hasn't had enough time? Be interested in what you find.
 

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Discussion Starter · #10 ·
Well I did have a CEL for a week or two, then it went away. This was around the time the oil leak picked up pace.

So I'm going to put the part in tomorrow and see how it goes. Thanks for the advice regarding not over-torquing the new pressure switch.

-Jim
 

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Forgot to add that the CEL went away before I got around to having it read.

-Jim
The Check Engine Light might have gone off, but the trouble code that led to it being on is usually stored in memory for up to 40 drive cycles so that past codes can be read for some time.

Also, the 2007 has a built-in code reader. If it hasn't been a long time since the CEL went off, and if the battery hasn't been disconnected in the meantime, the code can probably still be identified. See http://www.subaruoutback.org/forums...9-how-read-diagnostic-trouble-codes-dtcs.html

Let us know how the replacement goes, and the code, if it shows up.
 

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Discussion Starter · #13 ·
Thanks for the tip about the CEL codes. I felt like a member of a secret society going through those steps. Alas, the codes had been erased when I disconnected the battery recently. But it's good to know that I don't have to go to the auto parts store to get those codes read out in the future.

I put the new pressure sensor in this morning -- only tightening it to snug. The car no longer smokes and the dripping has almost disappeared. Will continue to monitor, obviously.

Thanks to all and especially "plain OM" for all the helpful info. Really saved me a lot of time and money.

-Jim
 
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