The cooling fans are supposed to turn on and off with engine temperature. Let your vehicle idle and the temperature gauge rise to around 1/2 way. The passenger side fan should turn on. Check to be sure it does, and let me know.
Did you use a Honda brand thermostat? If not, this could also be a problem. I have had bad success with non Honda parts. They are not built with the quality as the Honda brand.
Let me know what you find and we will take it from there.
I will be online off and on all day today until 5 eastern if you need me. I will be back in touch in touch asap.
Hello. I'm back, we can still communicate on this post. No problem.
Does the engine run hot while driving, or sitting still?
Ok, thanks! Did you bleed the system when you filled it with coolant? If not, it may have an air pocket in it. I'll be online off and on until 5 eastern and be back tomorrow to continue working with you.
Maybe. I'm more concerned with the overheating problem. Troubleshooting the idle surge is easy, most likely a thermal valve or idle air control valve, but that's no big deal. improper coolant flow can cause irregular idle also. So I want to concentrate on the overheating issue....might solve both problems at the same time.
Ok, I hate to be the bearer of bad news, but with a new Honda thermostat, fans operating correctly, new radiator, and the system bled correctly, that only leaves something internal such as a leaking head gasket or cracked head which would take a compression/leakdown test to determine.
Let's be certain the system doesn't have air in it. Turn the heater all the way to hot, open the bleeder screw and fill the radiator until pure fluid comes out the bleeder. I just want to be certain.
Ok, thank you. Let me make a suggestion. And I would make this suggestion even if you were in my shop. Instead of replacing the head gasket or head on this engine, I would suggest getting a lower mileage used engine. It's just more cost effective. The reason I say this is because if you spend the amount of money it's going to take to repair the head/head gasket....you still have an engine block with over 200k.....and it's hard to say when it will tear up. I just like my customers to get the most for their money.
You're welcome. Have a great day and thank you for the accept.