Hyundai Repair: 2000 hyundai tiburon, blown head gasket, hyundai tiburon

Question
Ok I have a few questions and need a lot of help.

First I was wondering what the compression needs to be when I check it from where the spark plugs are for my 4 from passenger side to driver side I got 50, 40, 40, 55 for the compression tests. Does this mean I have a blown head gasket?

Also my transmission will slip or stick in one gear and cause problems and when I put some trans fluid in it then its fine and the check engine light turns off what do you think the problem could be?

Also I have been over heating and it has gotten worse as of lately and my car wont keep water in it and well my inside is wet and I was thinking it was the heater core in the dash because when it over heats steam and stuff comes inside the car. So I was also wondering about this?

Please help me my car seems to be falling apart and I have taken care of it and dont know why it is doing all this

Answer
Presuming they're in PSI, your compression readings seem low, but don't indicate a blown head gasket.  A blown head gasket will indicate a low reading on one cylinder or on two adjacent cylinders, not on all of them.  Since you say the engine is overheating, it's possible you've done damage to the block or head, resulting in low compression readings.  Readings like yours are also consistent with improper camshaft timing.  But it's also possible you're not cranking the engine enough to get a good reading of full compression.

Regarding your transmission, you should check the fluid level and check for leaks.  If adding fluid makes the problem go away, that would suggest that the problem may well have been occurring because the fluid was low.  You should also check your engine and transmission diagnostic trouble codes.  This will help you know what things the computers saw that were abnormal.  

If you've got coolant inside the vehicle, it's a safe bet that you need a new heater core.  But if you're only seeing steam, you should do a good analysis to be sure it's not coming into the vehicle from under the hood.  Ideally, you'll want to find the source of the coolant leak by seeing the green fluid coming out of something.