So thinking I'd get a good start to themorning, I stopped by the gas station to pickup some Penzoil 10w40 oil (total of 2 quarts, was running low) and dumped it into my engine, which already had a little bit of 10w30 in it.

Hop onto the freeway and at about 40MPH, I start getting really thick white smoke out of my exhaust pipe. Pull over onto the shoulder and pop the hood, and temp's normal, no sign of anything that broke, and she's got enough fuel in her. No smoke will oe out the tailpipe if I'm going less then 40mph, but after that, its thick thick thick smoke. Enough that I couldn't see the drivers behind me.

I've checked the oil in the engine, appears to look like normal oil, so might this be coolant getting through the intake gasket?

Any ideas or advise would be greatly appreciated!

Thanks!

no, coolant leaking past the intake gaskets would contaminate the oil only, and not be burned off in the combustion chamber. Sounds to me like a blow head gasket or maybe even a cracked head. Have the system pressure checked when warm to see if you can find the leak.

Is there a way that the DIY home mechanic (ie me) can do this at home (pressure check)?

If I recall correctly, I think AutoZone has a loaner tool for that?

Whatever the issue is, I need to get it fixed by Monday morning. :(

Thanks!