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Hello all! I am posting because I'm trying to figure out exactly what is going on with my engine in my Loyale. For a while now, I have been having oil in my air box and intake snorkel. I have done a lot of work on this engine already, and with a baby on the way, I need it more reliable than ever. I'm due for a tune-up, but I don't want to spend money on an air filter and spark plugs when they're just going to get ruined again. Here's my issue: I have oil coming into my air box, and a pretty decent amount at that too. The whole bottom half of my air filter is covered in oil, with it puddling up at the bottom. The whole rubber intake snorkel going to the throttle body is coated with oil on the inside, pooling up in the grooves of it. My throttle body and inside my intake manifold remain clean, however. When I engine brake down long hills is when it seems to be happening, since when I get to the bottom of the hill and touch the gas, I get a cloud of blue smoke out the exhaust (temporarily), oil burning smell, the engine hesitates, and then goes back to normal when the oil is burned off. Going up hills and normal flat driving don't yield any abnormalities, and I can't see any blue smoke out the exhaust (from the rear view mirror). First things first, I took care of the obvious. Replaced the PCV valve with a genuine Subaru one and replaced all the PCV hoses. The T connections are free and clear, and I even have the updated design with the blue T fitting, and it's installed properly (don't have the T fittings switched around). I also have taken care of just about every single vacuum line in the engine bay since most were hard and cracking. When I replaced everything, the problem still continued, though arguable it got a little better, just a little. So the mystery is why is it still doing this? Just the other day I removed all the lines and PCV valve, made sure where the PCV valve goes into the intake manifold is free and clear. I have cleaned all the hoses and air box, but after just a drive or two, it goes back to the condition it's in now. Oil in the air box and intake snorkel, oil coated PCV lines lined on the inside with milky residue, similar to what you would find on an oil cap on an engine with head gasket issues. I presume this is just condensation, and it's worth noting that the oil cap has been replaced (it doesn't rattle; it seals properly) and it has no milky residue whatsoever. The oil in my air box becomes so much that it leaks out the bottom, spilling oil on my frame rail right underneath the air filter and eventually going onto the ground. What is this telling me? With all the basics covered and what all my extensive research has yielded, one can simply pass this off as blow-by. This doesn't make me a happy camper because again, I have a baby on the way so I can't have things like leaking piston rings. I had the piston rings go out on my old Loyale and I don't want to deal with that after the baby is born, so I'm trying to take care of things ASAP and fix everything properly, so my car is the last of my worries and I can focus my attention on the baby. So let's get into further diagnostics! I have a vacuum gauge hooked up in my car, and it reads perfectly. Like, I have not seen a vacuum gauge give more ideal readings on an engine. At idle when warmed up, it sits beautifully at around 22-23", like it should. The vacuum gauge is very responsive to throttle inputs and never fluctuates or crazy needle vibrations (my old Loyale had erratic readings on the vacuum gauge, indicating piston ring issues, and sure enough they went out on me). So according to the vacuum gauge, my engine is in good shape, at least the bottom end is. Today I did a compression test on the engine to see if it would yield any interesting results, and sure enough it did. The two cylinders on the passenger side of the engine (2 & 4) came out both at exactly 120 psi. However, the two cylinders on the driver's side (1 & 3) came out to exactly 60 psi. Obviously something is going on with that side of the engine. First idea for this would be my exhaust leak. The exhaust studs on that driver side cylinder head are completely messed up. When I bought the car, one exhaust stud was missing and the hole was oversized. Last time I had the engine out, the other stud decided to break off in the block. With careful attention to detail and help from coworkers at the shop I was working at, the best I could do was drill a hole in the broken stud, but we kept breaking drill bits because it was so hardened. Currently, the exhaust is barely being held on on that head, but it's sketchy to say the least. Bottom line, if I unbolt the exhaust, I don't know if I'll be able to get it to tighten again. I need a new cylinder head on that side to fix the problem, but I've been putting it off since I don't want to deal with all that work. So I have a minor exhaust leak from the bottom of that cylinder head (as well as a muffler about to fall off, getting a new one next paycheck though), and I'm not sure if that would affect compression test results but it is worth noting. My question is, where do I go from here? Obviously my next step is a leak down test, but it might be a short while before I can get my hands on a leak down tester and air compressor (might be able to do it at the shop I work at, but finding time is hard). So I'm looking for some advice as to what it might be. I am more than happy to throw "new" (used, but machined) heads on the engine and do the head gaskets, but if it's the piston rings, I'd be looking at changing out the long block since I don't have the tools or extra money to rebuild the block. I would much, much, much rather do the head gaskets. It'd be nice to know that they've been done and I've got a lot of new parts on this engine (replaced just about every oil seal/gasket, brand new lifters, timing belts, etc.) so it would already make the job that much easier/cheaper. Oh yeah, last thing to mention is oil and coolant consumption. I do not lose any coolant, as the coolant level in both the radiator and the overflow reservoir stay steady and topped off. However, even after replacing all the oil leaks, I do lose oil. About 1 quart every 1800 miles or so. Usually by the time I do my oil change at 3000, I have had to add about a quart and a half. Sometimes a little more, sometimes a little less. If it's blow-by, that means my rings are shot, yeah? If that's the case, then why is my vacuum gauge reading perfectly fine? Even if it was my valves having issues, that would be obvious on the vacuum gauge. So assuming the gauge is telling me the right things, then that means that I'll be needing to do the head gaskets and throw on some rebuilt heads with good valves and seals. But if THAT is the case, why is oil getting into my PCV and intake? The only thing I can think of is the valve seals letting oil in or something, but again, I feel like I would notice that on the vacuum gauge. Now I've never done a head gasket job before so I could be ignorant about small details inside the head that can cause things like this, but it's not outside my realm of what I can do/learn. Would the exhaust leak on that cylinder head affect compression reading? Would I fix the compression by replacing the head and fixing the exhaust? If so, how/why would that affect the oil getting in my intake? Any help is appreciated, even if it's just spit balling an idea. The baby is due in July and I'm trying to get this thing running like a top by the beginning of summer so I don't have to worry about my car. I could, and might, install an oil catch can just to ease the stress on the engine, but like I said, I like to get things done properly instead of just bypassing the issue. Thank you so much for reading all of this, I know it was a lot. I just try and give as many details as I can. I work as a technician and I know the smallest details can affect diagnostics a lot. Grant