What kind of engine you have ?
You need only to drain off a couple quarts of coolant to change the thermostat.
if it's coming out the exhaust manifold it could be a blown head gasket or cracked head.
Remove the water supply hose from the top of your 2003 Chevy Monte Carlo thermostat housing. Remove the thermostat housing retaining bolts. Lift the old thermostat out. Drop the new thermostat in and reverse the process.
To change the thermostat on a 2003 Dodge Neon SXT, first remove the drain plug to let the engine coolant drain into the pan. Unhook the coolant reservoir and remove the hose clamp. Spray the two thermostat housing mounting bolts with a solvent and pull out the old thermostat.
2003 izuzu anscender 6 cylinder
Had the same problem with my 2003 Axiom... It was my intake gasket. 50 dollar gasket.... easy fix
We have complete instructions and pictures at our enthusiasts website www.trailvoy.com
The 2003 Subaru thermostat is located inside of the thermostat housing, on the front of the engine. The thermostat will be near the bottom of the engine.
To change the thermostat on a 2003 Buick Rendezvous, first, ensure the engine is cool and disconnect the negative battery cable. Locate the thermostat housing, typically at the engine's front, and remove the bolts holding it in place. Take out the old thermostat and clean the mating surfaces before installing the new thermostat, ensuring it sits correctly. Finally, reattach the housing, reconnect the battery, and refill the coolant as necessary.
The thermostat housing is where the lower radiator hose attaches to the engine. remove the hose and the housing (2 bolts) and the thermostat is in there (it may come out with the housing)
thermostat location on 2003 Nissan altima
Where is the thermostat location on mazda protege 2003?