I just recently replaced the thermostat and after i cranked it up it started to smell like either sewer or something terible i can't describe it and i'm almost positive it was coming from the truck but when i was revving it it started shooting out either gas or water from the tail pipes i couldn't tell it was in a field and i've been getting terrible gas mileage i put in about $30.00 in gas and got about 100 miles out of it. I've put in a good synthetic replaced alot of the filters pcv valve alot of stuff i've only had it about 1 month its an 88 350 any help would be appreciated its just not running like when i bought it. Thanks