Severin

2000 TL with 293K miles, original radiator and cap.

For the last 2+ years or so in warmer weather (80+) the temp gauge will go to 3/4 when on back roads with A/C on, HWY too sometimes. With no obvious driving differences, the temp could drop back to normal. Highway speeds usually help.

Both fans are working per spec.
New water pump and thermostat in 2012 (yes, it still occurred before this).
No coolant loss/contamination.
Oil is perfect.
Radiator and reservoir are full (no bubbles).

I'll try the radiator cap, but I have no bubbles or loss of coolant.

Seems to be getting worse now.

How common is it to have a radiator get plugged on our cars?
I have a hard time believing it's the water pump (I remember it happening before the replacement too, though less often those days). When a pump fails, it usually leaks or the bearings go and its noisy as heck.

When the temp was slightly above normal, the OBD said the coolant temp was 115F.

Any suggestions? Will try the cap; can do the radiator, t-stat and temp sensor myself if need be.

01acls

Check for debris in front radiator and also in between the radiator and the condensor. Look at both of those and make sure the fins are not clog up.

Thermostat

Remove and temperature test it or replace.

Make sure coolant is 50/50 mix water and coolant... OEM.

You can also remove the upper and lower rad hose to see if something is obstructing the inside... like a deteriorating/separated hose.

Maybe your temp sensor is defective and sending a hot signal when the motor is not over heating.

If your OBDII is correct then it's a bad thermostat...
is the thermostat installed right side up and facing the right direction?

Severin

Coolant is OEM.

I will say that the condenser fins on the lower half are smashed to hell from road debris; has anyone tried combing these out? Anyone know the comb pitch off hand?

01acls

They sell multiple pitch combs.

MarcDavidoff

My bet is the radiator is clogged with debris

01tl4tl

You said no bubbles in rad BUT have you burped the radiator, per owner book method with idle and 2000 rpm segments,
Done with heater on hot and cabin fan blowing?
All hose clamps are tight?
Inside the res bottle cap is a hose that should sit in coolant- to transfer back and forth with rad at shutdown, That hose likes to fall off and then no transfer, can lose rad fluid without knowing it- which messes with fan operation
Zip-tie it on for safety and cap must be on securely on res bottle

You said fans on spec, so the driver fan runs as needed for temp- sitting at idle to test it should run 30 seconds or so and back off
And the AC ON makes both fans run?
There is something I read recently on here about hi/low rad fan speeds at different times/needs as determined by the ECU

If the condenser damage is blocking the rads intake of fresh air, fix it

anything on the gauge over 1-2 lines below half and dead steady regardless of operating conditions = a problem!!
Yours has been weird for over 2 years?

ck out the thermostat. Test for correct opening temp or just get a new Honda 2 stage from the dealer. One of the few parts its really important to use Honda stuff
As said above- make sure its in the right direction, and the dot is at the top- has to sit in correct position

Ck actual coolant temp in rad with cap left off at start, let it warm up and stick a
temp stick- gauge in it, looks like a candy thermometer
Watch the flow thru rad at idle and at 1500-2000 rpm

The easiest thing to do would be replace the sender for temp to dash,
see if its all been a hoax, before tearing the car apart

Reaper730

Hey, having a problem with my 2000 tl overheating. I was driving from work one day and notice the gauge starting to go up so I turned the AC off and it went back down. Got home let the car sit for about 3 hours and went back out. After I started the car the motor was reving in park like had my foot on the gas. Kinda sounded like a Diesel engine starting. Then when I put it in drive it seem as if the car wanted to drive on its own. Took it for a spin then came home disconnected the negative to reset the ecu for about 10 mins then started the car and it was back to normal. I did notice once I cranked the AC the problem happened again. Any thoughts on this issue. By the way trans, motor oil, and coolant were all ok and both fan were working

01tl4tl

welcome to the forum reaper. It sounds like you have read the threads on this subject.
Have you watched the coolant flow in rad thru cap opening and done the burping per owner book method? with idle till driver side fan cycles and 2000 rpm holds till fan cycles etc. Heater must be on Full Hot and cabin fan running during burping.
free owner book download from acura Acura Owners Site | Exclusive Knowledge, Service, & Benefits

How is the coolant condition? more than 5 years old is ready for change
I and others mentioned most of the common things to look for in post above this one
You have read this entire thread and done all the suggested things?
nothing blocking between rad and ac condenser in front of rad? nothing blocking condenser? bent fins limit airflow,
AC on is adding load,,is the wp recent? ever done?
Total miles on car now? maintenance items of the 105 service completed?

Any running of driver side fan for more than 1 minute, like 5-10 minutes after shutdown? that's a failing temp sensor A and causes many problems

The surge in idle
That's a dirty IACV, located inside the bottom of Throttle Body
a 2000 - its time for the intake manifold removal and cleaning of EGR passage and port system, easy DIY with basic hand tools- sockets and a torque wrench
We have a diy for most things you can do to your car!
With manifold removal you get TB along for the ride
Once on the workbench you separate the 2 parts and flip TB over- remove IACV cover (get a new gasket for the cover and for TB to manifold)
There ar pics on here of the details but IACV is a rod with an air slit in it- it rotates inside a chamber to adjust amount of air at idle, gets gummed up and carboned and the surge tells you its time for a little maintenance
There are several related clean and lubrication jobs you can do at the same time- throttle and cruise cables etc, will make the car run better overall

Figure 1.5 - 2 hours for manifold R&R EGR job, add 30 minutes to totally clean and fix the IACV (or buy new one about 80 dollars and install) a few minutes to lube cables yadayada
3 hours at a casual cautious pace, with breaks, and running in to look at diy online again
I need a laptop for the garage!

TIP!! no need to remove battery neg cable for ECU reset, that causes radio to lockdown and you have to input the security code
Avoid possible damage to battery terminals (unless you clean them while there)
and not effect radio by opening passenger front door- remove panel on end of dash
See the 7.5 amp fuse marked CLOCK? pull that out for for 1 minute and reinsert
Its the secret backup power for the ecu! causes reset to clear all codes and force a system self test.

Were you getting a flashing CEL on the dash lights? if so what codes were there?
parts stores will ck them for free, the port is just in front of shifter

Severin

Just an update to my overheating, now resolved:

I unbolted the top two radiator mounts and tilted the the radiator away from the condenser to gain some access in between the two. I then proceeded to remove debris at the bottom (leaves, etc). However, the real problem was 15 years of dirt and dust caked in the radiator fins themselves. Using an air gun connected to a compressor, I blew the radiator out from the fan side forward, ending up with a pile of dirt on the floor when done.

No more overheating. So, If you've tried everything else and it hasn't worked, I can vouch that dirt buildup in the fins will cause you to overheat! You can't see the dirt unless you separate the radiator & condenser like I did (easy).

01tl4tl

So, one of the 1st things to ck on overheat as described above = look for debris clogging radiator and condenser
Much easier than doing other worthless things
and its the thing our megamoderator fsttyms1 says to look at on every overheat thread! ck between the rads!!

01tl4tl

Imagine what the cabin air filters look like! They take in air from the slots in front of the windshield.
That same dirt clogging your rad, may be clogging your lungs too

Acura says to replace the pair (box contains 2) every 2 years!
Who has been slightly longer between changes? TL new to you? do the cabin filters!
Easy - easier if someone has done it once before. ck DIY

01acls

^ DUDE, Post # 2???

Seabright

01acls, that is what he did. Follow your excellent suggestions and posted back the result so we can all benefit. And thank you for your posts, they are informed and great reading.

01acls

LOL

Sorry my bad. I thought he check other stuff first and then just now check for debris.