I have a 94' Civic and it has always been a great runner. The temp gauge went up and down, up and down repeatedly and spit all my coolant into the overflow tank. So I thought it might be the thermostat. Well that wasn't it either. It was fine for about a day and tonight started acting up again. Is this my water pump? Waht do you all think?

 

That sounds like a blown head gasket. It happened to me and I did the same thing you did, I replaced the thermostat, then the radiator, then heard that was notorious when the gasket goes. Fixed it right up.

 

unfortunately, I second his opinion.

it's probably the head gasket. At least it's not a Cavalier. You'd definitely be buying a cylinder head as much as they crack

 

It could be a few things.

a. leaky head gasket as stated already
b. bad water pump
c. defective rad fan
d. defective thermostat

With (a), a leaky head gasket, the exhaust gases can cause the coolant to blow out.
In (b, c, or d), the coolant can get so hot that it actually boils out of the rad and reservoir tank.

 

Thank you for your info. I was not really thinking of that but now that you say that it does kind of make sense. I also thought that it may be the radiator cap. I will have to change the gasket to see if that does it.

 

it happend to me to and i did the same thing they did. Its a head gasket. get it fix right away