mbrown1000

Once again, makes a lot of sense and that's kind of what I was leaning towards as well. One question though, why would coolant continue dripping from the oil pan hours after the plug has been removed and the engine is cool? Could it just be taking that long to completely empty out to the point that it will no longer drip? I've never actually left an oil plug out any longer than it takes to get most of the oil out and it is no longer dripping any at all, so I don't know how long is normal for it to sit and drip. What you said would also explain why it is that, even when I put the cooling system under pressure with a tester, it won't leak. Could I artificially try heating the head and block in the area of the gasket from the outside via a heat gun while the system is under pressure to see if it starts leaking? Or would I never be able to 1) get it hot enough to expand and leak or 2) would it still not leak since the block and heads would have combustion pressure trying to push them apart?

It was definitely coolant. And yes, there is water around the rim of the oil fill neck and I can see coolant on the dipstick (with the oil) when I check it. There was UV dye in the oil but it was just because I had added some dye to the coolant to help me troubleshoot. Oil/coolant mix definitely glowed under the UV light. Still no milky chocolatey sludge though. There's no doubt in my mind it's coolant and that's what confuses me so much. Why is there no milky sludge???

Dropped the oil and coolant again last night. Lots of coolant in the oil. Or at least it looked like a lot, probably doesn't take too much to make all of the oil look tainted. Definitely had green glow from beginning to end of drain and then continued to slowly drip coolant/oil mix, I believe mostly coolant, overnight. Other than the green glow and massive reduction in viscosity, the oil looked normal...no foam, no chocolate look, nothing. And the coolant I drained was beautiful...absolutely no traces of oil whatsoever. I drained the oil before the coolant and, before I drained the coolant, I pressure tested the cooling system with the oil drain plug and oil filter still off to see if it would leak. I pumped both the actual radiator and the secondary reservoir (separately of course, not at the same time) up to about 16-18 psi and...nothing. If there were a slow leak between the water jacket and one of the oil passages in the head, shouldn't I have seen at least a steady drip when I pressurized the system? Like you guys, I still think it's the head gasket...just that none of this makes sense.

This makes a lot of sense. If the gasket is leaking between the water jacket and the oil passages, but is still good at the fire ring, then a leak down test or a compression check aren't going to show anything. Right?

As far as I know it's always had good coolant in it. I live in the South (Kentucky) so it never really gets cold enough to freeze coolant unless it's just straight water (and even then it would probably be fine). There are some minor external leaks on the bottom passenger side. Really more like just a little seepage. Not sure about the top side as I don't think I can really see it. The thing that really still get me is that there's no oil in the coolant. I even flushed it a couple of times with just distilled water and then drove it for a few days filled with just distilled water. When I drained the water, it had no hints at all of having oil in it. And the antifreeze that's in the oil is clean. I've seen cars with bad head gasket failure and the oil looks like thin chocolate milk. Mine still looks like perfectly colored oil with a slightly green tint to it. The whole thing is just really confusing me.

When I left it last night it was at about 16 - 17 psi. This morning it was at about 12 psi. Could that little bit of drop be explained by overnight atmospheric conditions? I'm also not 100% sure that the test cap I used had a perfect seal. Going to try it again tonight with another adapter.

Got it set up. Holding steady for now. Will report back in the morning. Thanks.

Thanks for the help, guys and these are all very good points. Here's what I tried last night: Did a pressure test on the cooling system. Started with the tester connected to the fill tank or secondary reservoir or whatever (this is one of the Subby's with a radiator, overflow, and the secondary reservoir or whatever on passenger side real close to the turbo). Pumped up to around 18-20 psi where the system began to release pressure back to the overflow tank. It released to about 15-16 psi and held steady. I removed both the oil fill cap and the dipstick. No pressure loss. I had already removed the banjo bolt for the oil feed line to the turbo. Looked inside the hole...only saw stagnant oil. No coolant spewing out or movement in the oil to suggest it was seeing pressure from somewhere. Left it on for a little while...no pressure loss. Next I moved it to the actual radiator, core, or whatever the appropriate term is. Pumped to around 18 psi where it released down to about 15-16 and again held steady. I guess the next step would be to drain the oil...again (this will be about the 5th time now) and pressure test with the oil system completely open to see if it still holds pressure? Am I correct in assuming that, in this particular situation, a compression test or a leak down test aren't really going to show me anything?

No, I'm sure I got everything connected back right. As you said, it's pretty idiot proof. Don't know if it was like this before I did the work or not. It's actually my father in law's and I've been driving it and doing some work on it for him. Just included that background information in case it helps.

I have a 2005 Baja. Recently I replaced all of the spark plugs, removed and cleaned the injectors, and removed the intercooler to clean the throttle body. Also, before doing all of this, I Seafoamed the upper and added some to the gas and oil. This was all to correct intermittent misfires and very rough idle. Good news is idle and misfires are gone. Bad news is, after doing all of this I changed the oil and found that it had coolant in it. At first I suspected head gasket (as we all know Subaru's and head gasket issues) but, what confuses me is, there is no oil in the coolant, engine is not overheating, no bubbling back through the fill tank from combustion pressure, and absolutely no loss of power. Other weird thing is, when I drain the oil, after the diluted oil has run out, mostly coolant mixed with a bit of oil will continue to slowly drip out for hours. Even overnight! By the way, obviously it's the 2.5L turbo and it has around 130k miles on it. If anybody has any suggestions please help. As of now I'm a bit stumped and don't want to tear into the heads until I'm sure that's what it is. Is there anything I can check to be absolutely confident that it's the head gasket(s)?