Tools you need for thermostat on a 2013-2018 Toyota RAV4

On the XA40 RAV4 the thermostat is not up on top of the engine where people expect it. It lives inside the water inlet housing bolted to the water pump on the lower front of the block, tucked behind and under the alternator, and the lower radiator hose plugs straight into it. That means the whole job is done from underneath: pull the plastic under cover, drain the radiator, pop one hose, and remove two 10 mm fasteners. No timing cover, no belt removal, no gasket sealant.

The two things that catch people are the lower 10 mm fastener, which usually has no room for a socket and extension (bring a stubby or ratcheting wrench), and the jiggle valve orientation. That little pin valve has to point up so trapped air can escape; install it sideways or down and you can end up with a bubble that makes the temp gauge swing or triggers an overheat. Also refill slowly with a spill-free funnel and let the engine reach operating temperature with the heater on full hot, because there is no bleeder screw on this cooling system.

Complete tool and parts list

Differences within the 2013-2018 generation

Every gas 2013-2018 RAV4 sold in North America uses the 2.5L 2AR-FE, so the sizes above cover the whole run. The 2016-2018 RAV4 Hybrid uses the 2AR-FXE; the thermostat and water inlet are in the same place with the same 10 mm fasteners, but it has an additional inverter coolant loop with its own reservoir and electric pump that must be bled separately. The 2012-2014 RAV4 EV has no engine thermostat at all.

Torque specs

How the job goes

1. Work on a cold engine. Park level, chock the rear wheels, loosen nothing hot.
2. Remove the radiator cap to let the system vent, then raise the front of the vehicle and set it on jack stands. Removing the driver's front wheel gives extra elbow room but is not required.
3. Remove the plastic engine under cover / lower splash shield: 10 mm (some 12 mm) bolts plus plastic pushpin clips.
4. Place the drain pan under the driver's side of the radiator, open the plastic drain cock by hand or with a flat screwdriver, and drain roughly 1-1.5 gallons. Drain the coolant reservoir too if you want a clean refill.
5. Locate the water inlet housing at the lower front of the block, behind/below the alternator, where the lower radiator hose connects.
6. Use hose clamp pliers to slide the spring clamp back, then twist and pull the lower radiator hose off the housing. Expect more coolant.
7. Remove the two 10 mm fasteners holding the water inlet to the water pump housing. The lower one is tight; use a stubby or ratcheting 10 mm wrench. Note that on many units the housing sits on studs with nuts.
8. Pull the water inlet off and remove the thermostat and its rubber O-ring gasket. Note the orientation of the jiggle (air bleed) valve before it comes out.
9. Clean both sealing faces with a plastic scraper and a rag. Do not scratch the aluminum and do not use RTV - the O-ring does all the sealing.
10. Fit the new O-ring onto the new thermostat, install it into the block with the jiggle valve at the top (roughly the 12 o'clock position, per the factory marking), and hold it in place while you refit the housing.
11. Reinstall the water inlet and tighten both fasteners evenly to about 9 ft-lb (12 Nm) - verify in the service manual. Do not overtighten into aluminum.
12. Reattach the lower radiator hose, push it fully onto the neck, and reposition the clamp behind the bead.
13. Close the radiator drain cock hand tight. Reinstall the under cover, lower the vehicle, and torque the wheel if you removed it.
14. Fill through the radiator neck with a spill-free funnel using pre-mixed Toyota pink SLLC. Fill the reservoir to the FULL line.
15. Start the engine with the funnel in place, run the heater on full hot, and let it idle until the thermostat opens and the upper hose gets hot and the fans cycle. Add coolant as the level drops and air burps out.
16. Remove the funnel, install the radiator cap, and check for leaks at the housing and hose.
17. Once cold, recheck the reservoir level and top off. Recheck again after a couple of drive cycles.

Watch out

The 10 mm fasteners, 10 mm/12 mm under cover bolts, and the water inlet location on the 2AR-FE are consistent across 2013-2018 RAV4s; double-check the water inlet torque and the exact thermostat part number for your VIN before assembly.

Other jobs on the 2013-2018 Toyota RAV4

Thermostat Replacement on other vehicles