someone help me out here!, Nissan engine problem??? Options

[95CelicaST]

Last weekend I bought another car. Its a 1995 Nissan Sentra GXE. The body has 130K, the import GA16DE has ~50K. I am now the 4th owner.

1st owner- bought from dealership. Sold it at some point to 2nd owner.

2nd owner- had car in for a tune-up which the mechanic botched somehow and they ended up blowing up the engine

3rd owner- bought it with no motor and had a shop put the new one in. Too many cars, so he sold it to me.

Alright, now thats out of the way...

we went out and test drove it. It runs great. Auto trans shifts great. A/C blows cold and all is grand. brand new tires, brakes and alignment. We buy it for 2650 and take it home. A few days later I noticed that the temperature gauge does not come up to halfway, making me think it is not ever getting up to temp (basing this off the Celica's operating temp). So I figure the thermostat needs to be replaced. No big deal. MY QUESTION IS, the car seems to be going through gas like none other. Could this be caused by the thermostat being shot? I don't think it would, but I figure I would ask. Once she finishes off the tank I can find out how bad of gas mileage it is getting, but what kind of things could I look for in the meantime?

EDIT: forgot to add that is has a new O2 sensor and new plugs and wires..

This post has been edited by 95CelicaST: Aug 24, 2006 - 6:15 PM