an off the wall guess not knowing your area,somewhere 500 or under,IF its only a head gasket.Chances are you'll need the head planed and that requires the head being "stripped of all components.Any one agreeing to just do a head gasket is not a mechanic,as heads usually warp or crack before the gasket goes......George
the garage should have a competent mechanich that is able to diagnost the problem the OBDII is only 96 and up but it sound like maybe a head gasket or a lost of compreccion in one or more of the cylinder but is hard to diagnost with out looking at it
your local toyota dealer shoud be able to tell you whats wrong for about 80 dollars and that should be apply towarsd the repair if you choose to do it there
if u go to a dealer u are looking at at least $75 an hour just to look at the problem plus most if not all the parts being marked up. Ask your friends if they know a reliable private mechanic and find out what his rates are . The big difference is going to be how can you wait if you can rate it may be money ahead to go with the private. if not it could be faster but more $ at a dealer
Hi and Marry Christmas this noise can be an exhaust leak, a blown head gasket, a loose sparkplug. Most likely a exhaust leak.
By internal engine problem they mean lack of compression due to worn rings, damaged valve or piston. There's no fix in a bottle or tune up that will fix it. You can have an engine leak down test done to see what the problem is. If your not planning on expensive engine work remove the #3 cylinders fuel injector wire connector and spark plug wire or coil. If the check engine light comes on just place a jumper wire on the injector wire connector, and ground the spark plug wire to a bolt on the engine. And hopefully by eliminating the slow burning and unburnt fuel from that cylinder you could pass the test. V6 or inline four? You can get by on five of six cylinders easier than three of four. People used to deactivate one or more cylinders to increase fuel mileage, but power would be down and the engine would run rough.
You overheated your motor, you may have trashed you rings.
The head gasket may be leaking also.
You need to have it looked at and a compression test.
Valve seals may have been burnt and cracked.
There is so many things that you may have ruined by overheating with no coolant.