2000 Pontiac Grand AM - coolant overflowing

[mckillin]

So I just picked up a 2000 Pontiac Grand AM 3.4L, 3 days ago with 181 km on it.
Car passed the emissions test, passed the safety.
Driving it home from the MTO coolant temp was going over half and then coolant started over flowing out.

He said LIM gasket was replaced, looks good and clean on outside. Oil is clean, just oil. and Coolant is just coolant (but green)
Im not positive if its the green universal new stuff or what. Waterpump looks older but dry. Thinking about starting with t stat and water pump and maybe dex cool. Just want to confirm Im going in the right direct and it wouldnt possibly be a LIM or head gasket?

Thanks in advance

 

[dsmuts]

Could be as simple as a thermostat

 

[mckillin]

Ya Im going to start with that... What are signs and symptoms I should be looking out for incase it is a head gasket?

Thanks

 

[dsmuts]

If it's overheated at all it's probably got a bad headgasket now. You might luck out but chances of a bad lim are really good and a bad hg are decent.

 

[mckillin]

Well I just drove from cold and within 4 minutes temp was at half. Under easy driving conditions

 

[dsmuts]

Mine does that normally.