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.
2003 izuzu anscender 6 cylinder
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.
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.
Where is the thermostat location on mazda protege 2003?
thermostat location on 2003 Nissan altima
where is the thermostat located in a 2003 buick lasaber
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)