I have an 05 Civic EX w/ 120,000 miles. For about six months now, the temp gauge has been shooting up to Hot but the engine doesn't over heat. The air conditioner and heat randomly stop working and occassionally the car trembles when I shift from reverse to drive. After having the thermostat replaced, timing belt replaced, temp gauge sensor replaced, radiator checked for leaks, and some other maintenance done (not sure- don't know about cars- oxygen something or other replaced b/c of check engine problem), my dad's mechanic (he's been going to him for 30+ years- honest man) said I have a leak in my head gasket. He sealed it and said if the car acts up again, they'll have to replace it. In the past 3 months, I've put over $1500 into it. If the head gasket needs to be replaced, I have no idea if it's really worth it to. Does anyone have an opinion?
Thanks!

 

Sounds like a blown head gasket to me. Inspect the head for warpage while it's off.

 

A leak down test is the easiest way to find out. If you can see bubbles in the rad its a pretty good sign your gonna need a head gasket. I would deff get the head sent out and check for warpage at a machine shop. Any time the car over heats you run the risk of serious damage to the head. Be prepared to spend upwards of $850 even as much as $3000if the head is cracked