Honda K20A2/K20A3/K24A1 Thermostat 19301-PNA-003

Honda K20A2/K20A3/K24A1 Thermostat - 19301-PNA-003

Your K20 or K24's overheating, running cold, or the check engine light's on with a thermostat code? Part number 19301-PNA-003 is the OEM thermostat assembly for K20A2, K20A3, and K24A1 engines. This is the complete assembly with the thermostat, housing, and O-ring gasket all in one piece. The thermostat regulates coolant flow through your engine to keep it at the right operating temperature. When it fails, you're either overheating because the thermostat's stuck closed, or your engine's running cold because it's stuck open. Fresh thermostat gets your engine temps back where they should be.

Here's How Thermostats Fail

Thermostats fail in two ways - they stick open or they stick closed. If it sticks closed, coolant can't flow to the radiator. Your engine overheats and you're watching your temp gauge climb into the red. If you keep driving it, you're warping the head or blowing the head gasket. If the thermostat sticks open, coolant's flowing through the radiator all the time even when the engine's cold. Your engine never gets up to proper operating temperature. You're getting terrible fuel economy, the heater doesn't blow hot, and you might be throwing a check engine light for low coolant temp. Either way, a stuck thermostat needs to be replaced. Don't try to run without one - your engine needs to get up to temp for proper combustion and oil viscosity.

Complete Assembly Makes the Job Easy

This thermostat comes as a complete assembly. You're getting the thermostat itself, the aluminum housing it sits in, and the O-ring gasket that seals it to the engine. You're not buying pieces separately and hoping they all fit together right. The whole assembly bolts on as one unit. Unbolt the old thermostat housing, pull it off, bolt the new one on. Way easier than trying to replace just the thermostat and reusing the old crusty housing. The housing can corrode or crack over time, and the O-ring gets hard and stops sealing. Fresh assembly means everything's new and you're not dealing with leaks from old parts.

Replace It Before It Leaves You Stranded

Thermostats don't give you much warning before they fail. One day your engine's running fine, the next day you're overheating on the side of the road. If your RSX, Civic Si, or CR-V's got high miles and you've never replaced the thermostat, it's on borrowed time. They typically fail around 100k miles but they can go anytime. If you're seeing any signs of cooling system issues - temp fluctuations, slow warmup, occasional overheating - replace the thermostat. It's a cheap fix compared to the tow truck and potential engine damage from overheating. If you're doing timing chain work or water pump replacement and you're in the cooling system anyway, throw a fresh thermostat in while you're there.

What You Get

• Honda OEM thermostat assembly (part number 19301-PNA-003)
• Complete assembly with thermostat, housing, and O-ring gasket
• Regulates coolant flow to maintain proper engine temperature
• Aluminum housing with integrated thermostat
• Same assembly your engine came with from the factory

Fits Your Car

• 2002-2006 Acura RSX Base and Type S
• 2002-2005 Honda Civic Si
• 2002-2006 Honda CR-V

Compatible Engines

• K20A2 (2002-2004 RSX Type S)
• K20A3 (2002-2006 RSX Base, 2002-2005 Civic Si EP3)
• K24A1 (2002-2006 CR-V)

Note: This is a complete assembly, thermostat, housing, and O-ring all together. You don't need to buy anything else. When you're installing it, let the engine cool down completely before you start. Drain some coolant from the radiator so it's below the level of the thermostat housing. Unbolt the old housing and pull it off. Clean the mating surface on the engine block. Bolt the new assembly on and torque the bolts to spec. Refill the cooling system and burp the air out. Start the engine and let it warm up to operating temperature. Check for leaks around the new housing. Make sure your temp gauge reads normal and the heater blows hot.