My 2000 TL has 252K on it. when it gets outside temp of 80 degress or warmer it overheats when i have the a/c on for about 10-15 minutes (a/c speed 3-4 inside temp set to 60 degrees). when it does that i turn a/c off and heater on with fan speed to 4 temp up to 80 and engine temp decreases fast. at this point i can turn heat down to speed 1 and temperature set to 60 and it wont' over heat as long as the a/c is off.
i replaced thermostat two years ago aftermarket part, both condensor fan and radiator fan have been replaced in the past 3 years. i flushed radiater last year. i have a feeling that the radiater still not doing its job never been replaced. its that or maybe the thermostat getting stuck closed.

any other ideas???

 

Hey Jpelizza, have you confirmed that the coolant is up to top level within the radiator ?

Also, make sure that the cooling fans are operating properly. Could be a faulty sensor.
If in doubt, have the cooling system pressure checked.

 

I'm thinking I should replace thermostat and the ect to start and see if that works.

 

Those (the thermostat, low coolant, fans) are about the only reasons I can think of... Have you checked the coolant level and if both fans come on?

 

To start with, verify that the cooling fans are working when the engine is overheating.

If replacing the T-stat, be sure to get the Honda 2 stage for best operation. Also, make sure that the coolant is a 50:50 blend, full and not leaking. Low coolant levels or trapped air pockets can fake out the sensors. Was the water pump replaced with the last new T-belt servicing ?

 

You might want to check the radiator area. Sometimes debris like leaves and so forth can get in there and hinder air flow.

 

ok, sorry so long for update. several weeks ago i thought i fixed the problem b/c it was just low on coolant. anyway it is hot out now like 90 degrees. i just filled up coolant again about 2 cups, but today it still overheats with a/c on. takes about 15 minutes for it to start overheating.
i havent spotted any leaks but even so it was just filled today and still overheating with a/c on. i'm thinking the thermostat is sticking or the radiator may be plugged??

i feel like just replacing the radiator, thermostat and ECT., what you think??

and yes the water pump was replaced with timing belt

 

Have ya had the system pressure checked ?
If not, do this before just randomly replacing parts.

 

pressure test system to find leak
its not losing coolant for no reason!

loose hose clamp, pinhole leak in hose, even faulty new wp can happen

burp system per owner book

 

OP- Had the same problem a while back. Listen to 01tl4tl he helped me through the same issue lol.

1. Find that leak! Fluid levels need to be adequate.
2. Make sure both fans are working with the a/c on!
3. Inspect radiator cap! A bad cap can cause fluid to "boil" out of reservoir. Cheap fix. If you're not sure I would just replace it. Cheap insurance.
4. Our TL's for some reason only like OEM thermostats. It keeps are cooling system running right. I suggest using OEM.
5. Inspect your hoses! Collapsed hose can cause overheating issues. Pressure test.
6. Its possible you have a clogged radiator!

When i was having my overheating issues it was only in hot weather, a/c on, and high rpms. No mechanic could figure out the issue as all tested fine and appeared to be in good working order. Ended up swapping so many parts that there wasn't anything left to change but the radiator itself. Turns out it was a little clogged.

I was at about 190k when this happened to me. It might be the same case for you! Good luck

 

Having similar issue, HELP!

Car over heats when idling, A/C on. Driver side fan not turning on.
When overheating, i turn the car off and the fans do not turn on automatically. Im almost certain they should turn on automatically if its overheating.

I had low fluid like 2 yrs ago and the fans would stay on after i turned the car off. Its no longer doing that.


Fluid is full.

Thermostat?

 

Try applying power by a jumper directly to the fan's motor connector. This will bypass the relay, fuse, sensors and switch for the fans. Once ya determine that the motor for the fans are ok, then backtrack the electrical circuit. Chances are that it's a bad ECT thermosensor. Make sure that the cooling system is burped of air.

 

As stated before my condenser(Driver) fan is not coming on @ all.

Assuming that the fan is good(i will test fan before i change any parts), which one do I have to get, #14 or #15? And should I just go ahead and change the thermostat? Car is @ 104k, never changed.

See image below.

 

Sure, I'd replace the thermostat, but as far as other parts, both fans should come on with the a/c regardless of engine temperature. Like 3.2TLc explained, running jumpers to the fan eliminate the sensors and relays. Turning on the a/c eliminates the sensors, but not the fuses and relays.

 

It was the fan, went to autozone and replaced. Both fans turn on now! thanks everyone!

If anyone else has this problem, CHECK FAN FIRST, and FUSES and RELAYS. Leave sensors for last. I replaced my condenser sensor switch for no reason

 

It's always best to know if the fan motor is operational before throwing unnecessary parts at the dead fan.
Good info to pass along !!!

 

Before you keep checking the coolant, thermostat etc. look closely at the a/c condenser.
My 99 with 220k was having the same issue. I had it before when a fan would go bad but it happened over the weekend and the fans are fine. What I found was that the fins in the condenser were pretty much pressed flat in a bunch of areas. 15 years of highway driving getting pelted by rocks, rock salt etc. have taken their toll. I began by taking a hose to the condenser/radiator and with mild pressure flushed out the fins. Then I took a small flathead screwdriver and carefully opened the majority of the damaged areas.
It took about 30 minutes of patience but when done the problem was gone, the a/c was WAY colder and the temp never moves past just below half where it normally stays.
Also I noticed the fans pulling a lot more air. So take a look you may be surprised.

 

The culprit was bad radiator. I didn't realize I was looking at condensor from front side of car, when I took radiator off it was CLEAR that it was all crudded up with stuff. Replaced radiator and no problems at all!

 

Here is pic of radiator!