If you are still losing coolant then points to head gasket although most will not run very well at all and can often sound like a blowing exhaust. Do you get white smoke coming from exhaust when revving at first?
Also when you refilled system did you make sure there are no air locks (check pipes when up to temp and also is hot air coming from heater?) Is coolant fan kicking in at running temp? Could have a bad rad switch.
Check under oil filler cap for white residue.
Can do some but it may or may not help; Make sure Spark Plugs are tight & Gasket at the base of the plugs are Good, Check to see if the Head Gasket is Leaking-is there an Exhaust in your Radiator? Lastly Check Compression........You may need Piston Rings.
No matter which way you look at it... the law requires a seller to provide a valid smog check certificate at the time of the vehicle's sale. However...
I can't give legal advise (I'm not a lawyer)...but if the buyer signed a waiver, admitting full on, that he/she is aware that the vehicle is being bought without a smog certificate because of a damaged engine or some other problem which needs repair, they probably wont have much chance in court.
The buyer still has the right to sue, and try to collect for repairs, but I can't imagine anyone would do this sort of thing, specially after signing a waiver. True that the BAR (bureau of Automotive Repairs) requires a smog certificate provided by the seller, however the DMV is only concerned with a smog certificate being presented before registration is transferred, regardless of WHO brings it in or gets it done(smogged).
around 20 - 50 max i would say average 30
you got a blown head gasket, or a warped or cracked head
there must be a leakage of coolant reservoir