On the XV50 Camry the thermostat is not up top on the intake side like many older cars - it is down in the water inlet housing where the lower radiator hose meets the engine. That means you drain the radiator, pull the plastic undercover, and work from below. On the 2.5L 2AR-FE and the hybrid 2AR-FXE it is a genuinely easy job with two 10 mm bolts in plain sight once the car is in the air. On the 3.5L 2GR-FE V6 everything is the same in concept but the housing sits lower and tighter, so plan on a long extension and a wobble adapter and some feeling around blind.
The two things people get wrong: installing the thermostat with the jiggle valve not pointing up, and not burping the system afterward. Either one gives you an overheat or no cabin heat and sends you back under the car. Also use the pink Toyota Super Long Life coolant pre-diluted - this generation is filled with it from the factory and mixing coolant types in the aluminum block is a bad trade for a few dollars saved.
| Item | Type | |
|---|---|---|
| Floor jack 2 ton minimum, lift at front pinch weld / crossmember Raise the front of the car to reach the undercover and water inlet. | Required | shop |
| Jack stands Pair, 2 ton, under front pinch welds Support the car while you work under the front. | Safety | shop |
| Socket set 10 mm and 12 mm sockets, 3/8 in drive 10 mm for undercover bolts and water inlet housing bolts; 12 mm for some splash shield and brace bolts. | Required | shop |
| Ratchet with extensions 3/8 in drive ratchet, 3 in and 6 in extensions plus swivel/wobble The housing bolts sit deep behind hoses and brackets, worst on the V6. | Required | shop |
| Trim clip / panel tool Plastic pry tool Release the push-pin clips holding the engine undercover and splash shields. | Required | shop |
| Hose clamp pliers Swivel-jaw spring clamp pliers or cable-type remote clamp pliers Toyota uses spring band clamps on the lower radiator hose and bypass hoses. | Required | shop |
| Drain pan 6 quart / low profile Catch coolant from the radiator drain and the opened housing. | Required | shop |
| Pliers Needle nose and standard Turn the plastic radiator drain cock and coax hoses off. | Required | shop |
| Pick set Hooked pick Pull the old rubber gasket out of the housing groove without gouging aluminum. | Recommended | shop |
| Gasket scraper Plastic or brass scraper Clean the sealing face without scratching the aluminum. | Recommended | shop |
| Torque wrench 1/4 or 3/8 in drive, 5-25 ft-lb / 60-250 in-lb range Housing bolts thread into aluminum and strip easily if overtightened. | Required | shop |
| Spill-free funnel kit Universal radiator funnel with Toyota adapter Fills and burps the system without an air pocket behind the thermostat. | Recommended | shop |
| Thermostat with gasket Toyota 90916-03134 (2AR-FE/2AR-FXE) or 90916-03145 (2GR-FE) type, 82C; gasket 16325-31020 / 16325-0H010 Replace the thermostat and always use a new rubber gasket. | Parts | shop |
| Toyota SLLC coolant Pink Super Long Life, pre-diluted, 1-2 gallons Refill; never mix with green or orange coolant in this system. | Consumables | shop |
| Distilled water 1 gallon Top-off and to rinse spills off paint and the subframe. | Consumables | shop |
| Shop towels and drain plug washer Lint-free towels Wipe the sealing surface dry before the new gasket goes in. | Consumables | shop |
| Safety glasses and nitrile gloves Hot coolant and overhead drips while working under the car. | Safety | shop |
All three engines use 10 mm head fasteners on the water inlet housing and undercover, so the socket sizes do not change. The difference is access: the 2.5L 2AR-FE and hybrid 2AR-FXE housing is on the lower driver's side and easy to reach, while the 3.5L 2GR-FE housing is lower on the front of the block and usually needs a 6 in extension plus a wobble or swivel, and sometimes a brace removed. Thermostat part numbers differ between the four-cylinder and the V6 even though both are 82C units.
| Water inlet housing bolts/nuts (2AR-FE / 2AR-FXE) | about 9 Nm (80 in-lb) - verify in the service manual |
| Water inlet housing bolts (2GR-FE) | verify in the service manual |
| Radiator drain cock | Hand tight only, do not use a wrench |
| Engine undercover bolts | about 8 Nm (70 in-lb) |
The 10 mm hardware and the water inlet location are consistent across the XV50 2.5L, hybrid and 3.5L V6, but I am not confident enough in the published housing bolt torque to state it as fact - look up the water inlet torque and the exact thermostat part number for your engine before final tightening.
It is inside the water inlet housing at the lower end of the engine, where the lower radiator hose connects - driver's side low on the 2.5L and hybrid, low on the front of the block on the 3.5L V6. You reach it from underneath after removing the plastic engine undercover.
You will only lose about 2-3 quarts draining the radiator for this job, so one gallon of pre-diluted Toyota pink SLLC is plenty. If you do a full drain and refill, the 2.5L holds roughly 6-7 quarts total and the V6 slightly more.
Yes. The thermostat seals with a rubber ring that takes a set; reusing it usually means a slow seep at the housing. Genuine thermostats come with a new gasket or you buy it separately (16325-31020 type). No sealant is needed.
Almost always trapped air or the thermostat installed with the jiggle valve not pointing up. Refill with a spill-free funnel, run the engine with the heater on full hot until the fans cycle, and recheck the level cold after a drive or two.