3

My car is a Honda Civic LX 2002, 4 cylinder. It is overheating after I've changed the thermostat, there are no cracks in the cylinder block and radiator, brand new gaskets.

  • Is the radiator blocked : does it allow sufficient coolant through? – Solar Mike Nov 26 '17 at 18:05
  • 1
    Did you use an OEM Honda thermostat? Did you ensure the system is completely bled? The D17A1 engine is a fickle beast when it comes to coolant. Having issues with my own '03 Civic LX. – Pᴀᴜʟsᴛᴇʀ2 Nov 26 '17 at 18:13
  • Was the car already overheating before you changed the thermostat, or only after? – Ives Nov 26 '17 at 19:12
  • The radiators on the left side so park it with that side facing up, start the car, and open the radiator, then pour coolant in until you stops seeing air bubbles. When air goes into the water jackets that's not how air cooling works. Make sure to let it cool down first, you want the radiator to be cool before you open the radiator. It builds up lots of pressure. If it's an emergency use plenty of towels and turn your face away. People suggest to upgrade the radioators because when sitting idle, they'll overheat because the fan itself isn't enough to cool down the radiator in hot weather. – GettingNifty Nov 26 '17 at 23:37
  • @GettingNifty - Actually, the radiator is in the center and the radiator cap is on the right side of the car (as with all things, in relation to where the driver sits). But yes, you want the radiator cap to be as up as you can get it when do int this. Sitting the vehicle up hill on an incline with the radiator cap at the highest point would get you the best results. – Pᴀᴜʟsᴛᴇʀ2 Nov 27 '17 at 15:41
1

There are a couple reasons for overheating.

Pressure
System can't build pressure, so boiling point is lower. Could be a leak, bad radiator cap, or an air pocket. Look for visible leaks, they will eave a white residue behind. If it is the cap, you will likely not have pressure in the upper hose. Coolant overflow bottle may overflow. Not sure on the best way to determine air pockets, other than process of elimination.

Thermostat
Temperature goes up quickly. Heat works and helps cool the engine, but will likely not be enough to keep it in the operating range.

Radiator
Could be partially clogged. Temperature increases slowly, especially under higher load. Heat helps bring it back down to normal. May be cold pots on the radiator. Both input and output hoses hot.

Fans
Fans don't come on. This will lead to overheating when you are stopped, but not when moving.

Water Pump
Little/no pressure in the top coolant hose. Top radiator hose also cold. Heat does not work.

Note
Be aware, heat not working could also be a clogged heater core, or bad heater core valve.

0

Be aware that some vehicles require specific "set up" to properly fill the cooling system. For example, my 2001 Passat requires that the coolant overflow tank be loosened and raised, so that the tank becomes the highest point of the system; then, a specific hose must be loosened to make sure that no air remains in that hose. I don't know if your Honda is like this, but a look at a shop manual (or speaking to someone who knows the model) might be useful.

And while this isn't an answer, I'll ask: is the water pump operating correctly? The symptoms you report could be caused by a failed pump.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.