GM Repair shop screwed up!! [00 GMC Jimmy]?

Some repair shops will only do what you want them too! First of all: If your heater was not working, and there was no other problem with your engine. Just meerly flushing the system may not solve your problem. " There is other things that should have been checked" (The repair facility knows this) And all the checks to find this problem is really simple. I would be very suspicious of the gasket blew after the engine over heated! There fore the real problem could have been solved to begin with . You posibly could have avoided all this if you just told them that your heater is not working. And not telling them to flush the system. The first thing I would have checked would be the fluid level in the resivor. If found empty, I would refill the system and check for leaks. If no leaks where found then I would check the thermostat for proper operation, My first suspision of this problem would be the sticking of the thermostat. The thermostat helps control the temp. of the engine by opening and closing. Often times the thermostat can get stuck fully closed,or fully open,or even somewhere in between. If it was stuck closed the water would not circulate enough to cool the engine. If it was stuck open the engine would be getting more water flow and keep the engine cooler. And also the heater would work,but would take longer to get heat from the vent,as it would take longer to heat up the water with the thermostat stuck in the full open position. Therefore I think that the thermostat was stuck closed if you could not get any heat at all,even after the engine overheated.( Word of caution when this happens! ) It is possible that if you had no water or antifreeze in the radiator the engine could overheat,and also at the same time not give any heat through your heater system. Overall I think that I would get a second opinion if you are able to get the vehicle there. It is possible that you could have a blown head gasket now,as well as an intake gasket. If this is the case there could be some bad news , there could be a warped head and or block . Let's hope not!! (BIG BUCKS) The heads would have to come off for checking and if warped resurfaced by a machine shop including the engine block!!!!!! If this is the case then look at having a engine replacement installed instead of repairl .You can also tell sometimes if the head has blown by looking at the oil. Pull the dip stick out and look for water on the stick, it could even look white or milky, If none is present you may be lucky. Also somtimes if you have a blown head or intake gasket the engine will run rough. After all this being said. If I where you, again I would get another opinion. If it leads you to believe that the only thing wrong is the intake gasket leak,let the dealer that quoted you do the work but at the same time replace the thermostat with a new one. Or better yet If you are mech. inclined enough you can change the thermostat yourself and then recheck to see if it over heats again and check if the heater works. I hope all this hasn't confussed you. PSS After the repairs are done, Be sure to vent the system as you add water or antifreeze back into the radiator/resivor. Good Luck