On the 5th-gen CR-V the thermostat is not a loose disc under a gooseneck at the top of the engine — it is a complete housing assembly bolted low on the block where the lower radiator hose lands. That means the work happens from underneath: drop the plastic undertray, drain the radiator, pull the lower hose off, and remove two small bolts. The parts cost is modest and the wrenching is easy; the time goes into draining, refilling and bleeding.
The thing people get wrong is the bleed. These engines trap air readily, and an incompletely bled system will throw a P0128, give you a heater that blows lukewarm, or let the gauge wander. Use a spill-free funnel, run the engine through at least two full fan cycles with the heater on max hot, and recheck the level after the first cool-down and again a day later. Second mistake: cranking the two M6 housing bolts down like they are suspension hardware. They go into aluminum at roughly 7 ft-lb.
| Item | Type | |
|---|---|---|
| Floor jack 2 ton minimum Raise the front of the vehicle to reach the undertray and lower radiator hose. | Required | shop |
| Jack stands 2 ton pair, under front subframe pinch points Support the car while you work under the front end. | Safety | shop |
| Socket set 10 mm and 12 mm, 3/8 in drive, 6-point Undertray/splash shield bolts (10 mm), some trim and bracket bolts (12 mm). | Required | shop |
| Ratchet and extensions 3/8 in drive, 3 in and 6 in extensions plus swivel/wobble Reaching the thermostat housing bolts behind the lower hose area. | Required | shop |
| Trim clip / panel removal tool Plastic pry set Pops the plastic rivets and clips holding the front undertray and inner fender edge. | Required | shop |
| Phillips screwdriver #2 Several undertray and splash shield screws, and the radiator drain petcock on some builds. | Required | shop |
| Drain pan 2 gallon low-profile Catch roughly 5-6 quarts of coolant from the radiator and hose. | Required | shop |
| Hose clamp pliers Spring band clamp pliers, cable-type preferred Honda uses spring band clamps on the lower radiator hose and thermostat hose; a cable type lets you park the clamp out of the way. | Required | shop |
| Hose removal tool / pick set 90-degree pick or hose pick Break the hose loose from the housing neck without tearing it. | Recommended | shop |
| 8 mm socket or nut driver 1/4 in drive Some housing and bracket fasteners on the 1.5T and hybrid use 8 mm heads; have both 8 and 10 mm on hand. | Recommended | shop |
| Torque wrench 1/4 in or 3/8 in drive, 5-25 ft-lb range Thermostat housing bolts thread into aluminum and are easy to strip. | Required | shop |
| Spill-free coolant funnel kit Universal radiator neck adapter set Fills and burps the system without air pockets; the 5th gen is fussy about trapped air. | Required | shop |
| Shop rags and brake/parts cleaner Aerosol, non-chlorinated Clean the block mating surface so the new seal seats dry and clean. | Consumables | shop |
| Thermostat assembly OE Honda thermostat with housing/cover and rubber seal — 1.5T (L15BE), 2.4 (K24W) and 2.0 hybrid (LFA) use different part numbers The replacement unit; buy by VIN to get the correct engine version. | Parts | shop |
| Honda Type 2 coolant Blue, pre-mixed, 1 gallon (buy 2 gallons if flushing) Refill; do not substitute green or orange coolant in these aluminum engines. | Consumables | shop |
| Distilled water 1 gallon Topping off and rinsing spills; never use tap water. | Consumables | shop |
| Replacement hose clamp Worm-gear clamp sized for lower radiator hose, if original spring clamp is weak Backup if the factory spring clamp has lost tension. | Consumables | shop |
| Nitrile gloves and safety glasses Coolant is an irritant and will run down your arm when the hose comes off. | Safety | shop |
| Wheel chocks Pair Keep the vehicle from rolling while raised at the front. | Safety | shop |
| OBD2 scan tool Live data capable (coolant temp PID) Confirm the engine reaches and holds normal operating temp and clear any stored P0128/P0125. | Recommended | shop |
The 2.4 K24W puts the thermostat housing in plain view facing the radiator, so it is the easiest of the three; the 1.5T L15BE has the same 10 mm bolts but far tighter clearance, and pulling the driver-side front wheel and inner splash shield helps a lot. The 2.0 hybrid (LFA) uses the same basic approach on the engine circuit, but it has a second, separate IPU/motor coolant loop with its own electric pump that you should not drain or bleed as part of this job. Thermostat assembly part numbers and coolant capacity differ by engine (roughly 5.5 qt for the 1.5T, about 6 qt for the 2.4), so order by VIN.
| Thermostat housing / cover bolts (M6 into aluminum block) | 9.8 Nm (7 ft-lb) — verify in the service manual |
| Radiator drain plug (plastic) | Hand tight only, do not use a tool |
| Undertray / splash shield bolts | 9 Nm (7 ft-lb) |
| Front wheel lug nuts (if wheel removed for access) | 108 Nm (80 ft-lb) |
Housing bolt heads are 10 mm on most 5th-gen CR-V engines with some 8 mm fasteners on the 1.5T and hybrid, and the M6-into-aluminum torque is about 7 ft-lb — confirm the exact bolt size and torque plus the drain and bleed procedure for your engine in the Honda service information before final tightening.
It is an integrated thermostat-and-housing assembly bolted to the lower part of the engine block, at the point where the lower radiator hose connects. You reach it from underneath after removing the front plastic undertray.
Most 5th-gen CR-V engines use two M6 bolts with 10 mm heads on a 3/8 in drive with a short extension. Keep an 8 mm socket handy too, since some 1.5T and hybrid brackets and fasteners in the way use 8 mm heads.
Plan on about 5.5 quarts for the 1.5 turbo and around 6 quarts for the 2.4, of which you will recover most from the radiator drain. Use Honda Type 2 blue pre-mixed long-life coolant only — do not substitute universal green or orange.
Almost always trapped air or a thermostat installed with the jiggle valve in the wrong position. Re-bleed with a spill-free funnel through two full cooling fan cycles with the heater on max hot, then recheck the level after the engine has cooled.