Black TL

Hey guys,

My friend has a 2003 TLS with 175k on the clock. Last week he said the car started overheating while he was in traffic (needle at 75% between C and H).

I asked him to check if the fan came on based on previous comments on the site. He will get back to me on this today. I was also thinking of replacing the thermostat to start with given it's the cheapest item that could cause the problem. The car has plenty of antifreeze in it and there are no leaks. What else should we be checking?

Thanks

Black TL

Oh one more thing. How do you check for a clogged radiator?

Skirmich

If the car has always been on A/F then its almost impossible that the radiator is clogged...

Most likely a Bad Sensor and/or Fan Temp Switch... If not the most expensive Item that can cause Overheating is the Water Pump getting seized.

Black TL

Does a water pump make noise if its bad? How do i check this?

Thanks

Skirmich

There is no Easy test with our Timing Belt Driven Water Pump.
With other cars you could check by hand the Pump Shaft but in our cars is very difficult to do it that way.

Honda techs have a Pressure Tool that they attach into the radiator cap to test it, But most of us Doesnt have it. So the easy way is to go to a honda dealer and have that Done IF everything else fails..

01tl4tl

water pump has a weep hole that leaks coolant when its shaft seal blows
look up from under car for whitish trace line

the additives in old coolant go acidic after 5 years MAX--
radiators are aluminum
thats how they get crudded up and dont flow!!

a non contact heat guage pointed at spots on rad can tell if flow is happening or not

feel the hoses,,top hot as it exits engine and enters rad
bottem hose medium

RC99TL

I had the same issue just recently. I have just over 200k and when the car was in traffic with the A/C on the temp would rise. The fan was turning but checked closely it was turning much slower than the radiator fan next to it. Replaced the fan motor (like $125 -Yikes!) and now all is good. I took apart the old motor and the stator brushes were worn down to the wires! and the inside was FILLED with the remaining dust. With the Auto temp the A/C runs often as does the fan, so after almost 14 years and 200 thou is guess it's understandable.

acutee

Spin the fans by hand and see if they are turning freely. sounds like fans are not running properly. You got everything as suggested from Thermo, Temp sensor, Fan motor.

01tl4tl

aftermarket fan motors are fine to use and less $$

14thandeuclid

Fan temp sensor .. or theres another sensor too. Can't remember the name of it (not air idle controller .. but start with those. It's unlikely the fan is gone, and is prob more costly then buying a 40 dollar switch and trial/error if you can't test the current on it.

Black TL

We tried getting the thermostat out put couldnt figure out how to get that bottom screw out. Does anyone know of an easy way pls?