Can't locate thermostat on 08 corolla

The thermostat is located on a housing on the engine block, follow the lower radiator hose towards the engine and you will see the housing, remove the 10mm nuts and the housing, the thermostat is inside, don't forget to drain the coolant first.

1. • 1 Pop the hood and locate the thermostat. It's on the passenger side of the engine and has a plug leading into it.
     
   • 2 Unplug the thermostat housing from the engine block using the 3/8-inch ratchet and socket set. The housing will come off in your hand and then you can pull out the old thermostat.
     
   • 3 Scrape off the engine block and the thermostat housing's mounting surfaces with the gasket scraper. This is to ensure the replacement gasket seals correctly.
     
   • 4 Place the replacement thermostat into the engine block and place the gasket over the ends of the bolts in the thermostat housing to keep them aligned.
     
   • 5 Bolt the thermostat housing into the engine block using the 3/8-inch ratchet and socket set.
     

Read more: How to Change the Thermostat on a PT Cruiser ' eHow.com http://www.ehow.com/how_5643178_change-thermostat-pt-cruiser.html#ixzz1g9B0K8Go

follow the radiator hoses 2 the motor normerly were the top hose connects 2 the motor is the thermostat housing.but on some japanese cars the thermostat can be on the bottom hose make sure motor is cooled down as there is a lot of heat&pressure in the cooling system

The thermostat is located inside the thermostat housing. To find it follow the upper radiator hose to the engine block.
Depending what size of engine you have the location is different.
The thermostat on this vehicle's (the Envoy & Trailblazer are essentially the same vehicle) In-line 6 cylinder engine is on the driver's side of the engine, below & behind the alternator.
If you have a V8 cylinder engine is in front of engine see the picture. Item 303 thermostat housing, 305 thermostat, and 304 thermostat gasket.

follow your return hose to your radiator

It shouldn't be bubbling into your overflow tank.If you follow the top radiator hose from the radiator to the other end of the top radiator hose the housing it connects to has your thermostat inside it.

Follow the lower radiator hose from the radiator to the engine. It connects to the engine at the thermostat housing. Remove the hose and the nuts holding the housing on. The thermostat in in there.

Grab top radiator hose, and follow back to engine. The part the hose is clamped to is the thermostat housing.
Remove the hose, and 2 bolts for the housing and the thermostat is revealed.

the thermostat is located at the end of the top radiator hose that runs near the radiator cap. follow the hose and at the end is your thermostat housing. the thermostat is inside the housing. Be sure to replace with same degree thermostat and in the same position you take it off.

Follow the top radiator hose to the engine block thats where you will find the thermostat housing inside there is the thermostat.
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