Hey all, first time poster here; long history speech but please, bear with me:
I bought my GT (1998 3.8L Series II N/A) 13 months ago, and two weeks later got rod-knock on a road trip. Had about 150k miles on it.
I had the engine rebuilt by a machine shop, and put in by a really good backyard mechanic my family has had nothing but great experiences with. We didn't have enough oil when he was putting it in (about half a quart short), so he recommended I top it off. I accidentally put half a quart or so too much in, and drove it for about 5-10 miles like that. I started leaking oil within the next few days, took it back to the machine shop and they said I saturated the rear engine seal by having too much oil and that was why it was leaking. I found if I parked facing downhill, it wouldn't leak. It's been a few months since I noticed any drips.
I am about 5.5k miles and 11 months on the rebuild, and now I'm burning oil like a MOFO. I changed my oil 3 weeks ago and I'm down over a quart. I checked the PCV Valve, which was clicking around fine, but it was covered with oil; I replaced it anyway just in case. I'm assuming I have oil in my intake plenum as well, but haven't taken it out to check.
My question to you guys is, what other possible factors could cause this much oil consumption? The engine doesn't seem to have any other vacuum lines associated with the PCV system; could it be blocked somewhere else and still sucking up oil through the valve? Or is it more likely something serious, like a bad intake manifold/head gasket seal or something?
Sorry for the TLDR; it's a long story.
P.S. The machine shop ****ed up the rebuild and didn't torque down a rocker arm bolt, causing the engine to misfire and the bolt to back off a half inch over a 2 block drive. I don't trust these guys.