Bad Valve Seals? How To?

[1uniquegeo]

I Think I Might Have Bad Valve Seals On My 94 Prizm. This Puff Of White Smoke Comes Out When I Start My Car, More So After It Sits Overnight. Is This Common On The 1.8 Liter Engine? It Has Just About 126K On It, The Car Has Been Well Maintained By The Previous Owner That I Know Of. It Seems Like It Uses About 1 Quart Of 5w30 Between Each Oil Change. I've Been Told That If I Use A Little Heavier Oil That It Will Be Harder To "Consume" Can Someone Confirm Any Of This. Any Help Will Be Greatly Appreciated. Also Has Anyone Ever Replaced The Seals On There 1.8L How Hard Is It And Can It Be Done By A "Driveway Mechanic" Please Help With This. - Drew