overheating

i have a 95 cutlass thats just started overheating. the guage goes up and right back down up then down. the guy at the garage diagnosed it as a cracked head or head gasket in about fifteen minutes i think hes full of it .any ideas?

start the engine up, and look for air bubbles in the coolant recovery tank, or you could take off the radiator cap (when it's cold, obviously) and watch for air bubbles there, also. If you see air bubbles, you have what your mechanic told you. By your symptoms I would agree with your mechanic.

a safer way of check for the same problem is simply by pulling your oil dipstick out and checking to see if there is any water, or if the oil seems watered down, if its a head gasket problem you will run into stranger problems down the road. check you heater, if there is little to no heat coming through the while the heat is one ful blast,then you could have what is called 'air bound' coolant lines. which is easier to fix. but if both what dwalomp and i suggest to check for is in fact the case then your mechanic is truthful. not all mechanics are out to get your wallet.

thanks for responding,my brother and i changed the temperture sensor thing yesterday and it seems to be fixed. i've put about 25 miles on it and it' set in my driveway and idled for quite some time. i just can't believe that fixed it. i'm paronoid i guess . it just makes me wonder why the mechanic wouldn't even check the obvious stuff first? i'd rather try an eight dollar sensor before giving him a thousand for a cracked head that wasn't cracked

Wow, good call. I have never heard of one of those going bad. It's just a thermoresister. But I'm glad you fixed it that cheap.

i just got lucky this time, thanks to the post on this web site.this is the best place i've found for usefull information so far.thanks again

If thats a 3100 make sure you bleed the coolant..... air bubble will cause that to happen.