Nissan Repair: 98 Nissan Sentra, blown head gasket, nissan sentra

Question
We have a Sentra that had a leak around the valve cover. We replaced the gasket, then  the car started to "puff" white smoke from the exhaust and to hesitate. It also started blowing oil out! It used a quart in less than 10 miles! From what we can tell, the oil is not coming from the top of the engine as the oil was mainly on the right wheel well and under the car.(there is no oil on the ground when it's parked) We replaced the spark plugs and lost most of the hesitation but not all. It was suggested that we had gotten bad gas, so we bought "sea foam" cleaner to put in it. Still smokes!! Not all the time, just puffs. Larger puffs when the engine is under stress...take off or after it gets hot.
Any ideas?

Answer
Hi Donna -

Are you still losing oil?

I would first take a compression test and see what is going on in the engine. Perhaps the head gasket blew, or valve seals. Compression test will tell you.

White smoke from the exhaust that dissipates quickly is usually steam, meaning a blown head gasket. Thicker, bluish smoke that kind of lingers in the air is oil burning, meaning valve seals.

Let me know -
aloha
calvin