Be weary of a thrown rod/spun bearing take the head off and look for hole in the piston. If you hear knocking at all with the symptomatic details in your post even a slight knocking can be the start of it.

 

Actually, it did overheat last summer due to a faulty fan relay, and when it is first started up there is a slight tapping but it quickly goes away. Thanks for all the help guys, I really appreciate it.

 

I'm also going to say rings. When the rings are worn it allows oil to get through and thus you see it burning out the rear

 

Smoking under a load I would think rings and with the start-up problem oil id from the top. Oil generally does not leak up hill in great quantities. So is the spark plugs collectin oil on the part you gap or the outside of the engine. If the outside the I would suspect leaky spark plug tubes. But the start up problem is probably valves. If it overheated can have several problems exspecially with higher milage.

 

I'd say you can defineately rule out the spark plug tubes seals, that couldn't possibly cause the engine to smoke. If you're getting a lot of smoke on start up it's gotta be valves or the head gasket as the oil can't run up past bad rings. It could defineately be a combination of things though, so start with a compression test and probably be ready to pull the head. Out of curiosity you never said whether it's sohc or dohc.

 

um, yes the oil can run up past the rings! My saturn as all saturns burned oil at high RPM's under load. my neon does the same thing. The walls are coated in oil anytime the engine is running to prevent the motor from ceasing, read up on how it works first, DUMBASS!

 

I said if it's smoking on start-up. Read the post first DUMBASS. If the oil's runnin up past the rings while the engines off you've flipped your car.

 

Yeah chase is correct, hes backed me I gotta back him on this and all the posts i have seem from him are credible - he is def not a dumbass - no way are rings gonna cause smoke on startup - high load yeah - something seems real fishy here tho - im willing to bet, but I could be wayyyyyyy off, its something with the exhaust valves - oil is leaking down past the seals and the guides and into the cylinder when its cold and the engine hasnt heated up enough for the to clearance to tighten up - the reason I say this is that there is the low pressure created in the exhaust manifold in between exhaust events for different cylinders helping to pull the oil down into the exhaust port even at low loads when cold - as the engine heats up the clearance between the valve and the guide becomes less, it becomes more difficult for the oil to make its way down there and only happens at very high loads when the vacuum in the the exhaust manifold is highest between the pulses due to more air being flowed through the engine, the scavenging effect being the culprit per sae. This is the best explanation I can come up with... Id look in that direction, has to be valve related in some way id say but id also agree that it could be a combination of things throwing us all off...