2002 TL-S. For the first time ever yesterday, my temp gauge went to half way and a little higher, and some coolant came out the overflow.

Opened hood and observed neither cooling fan running. Turned on AC and both fans started working and blowing hard. Temp gauge went back down. Turned off AC and let it idle. Temp climbed back up some, fans came on, but only seemed to be blowing at half speed.

After some searching & reading, many stated their fan(s) ran some after car was turned off. I have never heard my fan(s) run after turning off the car and the car has never run hot.

How should the 2 fans operate on a 2002 TLS?
Is there 2 speeds the fans can run at, or this a problem?
Is this likely a fan relay or a temp sensor?

Thanks! This problem just showed up yesterday and I haven't had time to check it out any better yet. Thought if it is probably a relay or 2, I'd just go by the parts store at lunch break and get the relay.

 

driver fan works on fan sensor A, like at stoplights when it cycles for a few seconds.
pass fan works with AC on
BOTH run with AC

NOW, does the driver fan run more than 1-2 minutes after shutdown at normal temp?
thats a bad fan sensor A

relays control power to a device, since fan operates its not a relay
you can swap it with one of same color to test possible failing mode

The fans are 1 speed, ON, and have different blades so they dont pull same amount.
spin fan blades by hand- when engine cold- are they free or any drag?

slight temp rise to half should not have overfilled the res bottle causing overflow
Was it pumping out under pressure?
was its level correct before? Set the rad and res bottle to correct levels now and monitor

ALSO you need to do a full burp of the cooling system
see owner book for details of your year
no owner book? free download here at www.owners.acura.com
need cars VIN to register

 

call local parts store and ask for a `fan temp sensor A`
its located on lower right/pass corner of rad
screws in--no biggie to change and a very common failure

is your coolant recent- under 5 years, and water pump good?

 

What is the coolant level in the radiator

 

Coolant level in radiator was low after it got hot. Never been low before. Added some to it, haven't read/done the burping procedure yet.

Quickly looking at AutoZone website, they have:
"Cooling Fan Switch-Radiator" it sez is located in thermostat housing & stamped "A-99"
"Cooling Fan Switch-Radiator" it sez is located on front cylinder head
(WTF ??? it sez Radiator, then describes it as being somewhere else)
"Cooling Fan Control" which seems to be a thermosat
"Electric Cooling Fan Thermostat" (maybe aftermarket adjustable thermo??)
and the Relay...
Let me check it out more during lunch coming up in just a few minutes.
So the passenger side fan should only work with the AC on??

 

it also works during extreme overheat--iirc but normal is only with ac then its both fans

after filling rad and res bottles to correct levels, ck around for leak--water pump been replaced yet with timing belt?
hose inside res cap fall off?

low coolant can trick other systems, fill then test fans
Part of the burping involves waiting for driver fan to operate then go off,,again and off, then idle and repeat...see owner book

Go in person to parts store where they have better diagrams
99s sensor was at thermostat, later years=lower right corner of rad

 

all I found wrong was the tube inside the overflow tank/expansion tank that runs from under the cap down to the bottom of the tank had fallen off. I had to burp a little, but it idled for 20 minutes and never heated up enough to get above its usual 1/3 reading on the gauge. Never got hot enough to kick off the fans after 20 minutes of idling. It was about 60 degrees outside.
Both fans spin freely and both come on with the AC.

We had one the hottest summers ever this year and my temp gauge never got above approx 1/3 running the AC full out. Don't know what happened, but it seems to be OK for now. I'm sure if something is wrong, it will show up again soon enough.
Thanks!!!

 

Hey Alan, It may've been just that simple....hopefully, good luck !
If only all problems were that easy to resolve, just wonder how long it's been like that.

 

replace your thermostat with a genuine honda one
1-2 lines below half is the normal temp,,,not 1/3
thats way to cool

driver fan should run a little on and off at long lights
from cold in the driveway at idle it may take a while
what does it do driving?

that res cap hose is critical= when it falls off there is no transfer back to the engine when it goes from hot to cold overnight,,then rad is low,,fan sensor gets fooled...

 

Hopefully thats what is was....Do need to flush & replace coolant & stat.
I'll get a Honda stat, but what about the anti-freeze...is getting the Honda brand important on this item, or any good brand of the appropiate type???

 

fallen res cap hose will cause that fluid loss,,keep an eye on it..maybe replace that hose?
temps fine if 1-2 below half,,I said thermostat due to 1/3 = low temp,,
watch your fan op after a warmup drive,,make sure that sensor is working right

coolant brand? thats up to you,,there are honda loyalist, and there people who read the label on parts store products = APPROVED FOR ACURA means it has the right stuff
and not the BAD stuff for us
not all brands comply but most do these days

coolant more than 5 years in use is bad = additives turn acidic in aluminum home

 

I used a Zip Tie for a clamp.....I mean, you can't do a better repair than one using zip ties..right? Unless maybe one involving both zip ties and duct tape

Thanks for the info, its been about 5 years since the 105,000 big service on everything, so its time. I'll probably do a new stat anyway, they don't seem to make them like they use to.

 

Hey Alan, the Honda 2 stage T-stat is specially engineered for optimum performance. It's critical to orient the part properly when installing. When at the dealership, price their coolant to compare with a quality product such as Prestone's advanced formula.
Also, consider replacing the hoses if they were not done at the 105k service. While you're in there check out the thermosensor for the cooling fan. For somewhere around a $100 in parts & "DIY", you'll be good to go until the next T-belt service.

 

zip tie is fine as long as the hose itself fits snugly on the fitting
not swollen on the end for example

Its pressure sensitive--no air leaks allowed or you get that temp/overflow!

 

agree on new rad and heater hoses with t-stat etc
make the system 100% and enjoy 5 more years of trouble free motoring