i was driving today nothing out of the ordinary and i rarely look at the temp gauge. as i checked it was so very close to the red line. i pulled over immediately and it went down like 1cm then while still at idle it shot back up. i immediately turned off the engine opened the hood (no steam) and checked the coolant. it seemed almost full. i couldnt see the min/max lines but it might even be over the max. after a few minutes i turned it on again and it slowly crept up higher and higher. i turned it off for a good hour and then it was fine. no more overheating problems. no leaks that i could find. im thinking maybe water pump is beginning to fail? any input guys

fyi 01 tl 99,500 miles

 

or sensor going bad maybe?

 

what sensor? would that cause an overheat? or are you trying to say the gauge is just misreading. i dunno if i was being paranoid but when i lifted the hood it did seem a little hotter than usual

 

Check the coolant inside the radiator cap- green is good
foamy grey is bad
Look at the oil dipstick
Clean and oil to full= good
Black and burned smell= bad
Coolant overflow tank- between min and max lines

Then we can begin to help you

 

And the radiator fans-are they working?
Driver side runs when engine hot
Passenger side when AC on and when needed for hot

 

At that many miles you should change the thermostat. It might be sticking.

 

Thermostat is sticking. REPLACE IT! But get one from Honda/Acura. Don't use aftermarket.

 

that can also happen from a pinhole leak in your hoses. when that happens, idling make is heat up fast since the water pump is at its lowest speed and the pressure in the system is leaking out. if you put it in neutral and rev it a little, you can watch the temp come down as the water pump works faster.

 

It could also be your fan relay sensor is not working. If it was thermostat, feel the upper hose temperature with your hand, but be careful. If the hose is very warm, then more likely it is not thermalstat.

 

the problem hasnt occured since then. does that rule out any of the suggestions above?

 

You need to have it checked for actual coolant temp in the radiator with a thermomter or infrared temp reader.
Then we can see what is stuck or worn out or...
Do the fans work as described?
Do the obvious checks- not - well it seeeeeems fine...........
Thats a fun way to spend the 4th- stranded with a blown motor!

 

another thing to consider was if you were running the ac...? my car 00tlp would get hot with the ac on but as soon as i turned it off the temperature would go back to normal. i dont mean to thread jack but what would cause this to happen?

 

You have a problem too!

The TL should always run approx 1 mark below half on the temp- all the time
I can run up to the 7000 foot mountains in the blazing heat with AC blasting and the temp stays right where it belongs

 

 

fans work and oils seem fine. didnt check coolant color will do so later today. again, the problem hasn't happened since so should i be THAT worried or is it more like the terrorist orangish, pinkish, maroonish alert for me? blown motor? you sure?

 

Something could be stuck and then freed itself- crud in the coolant lets say- getting stuck in the thermostat...or the radiator is plugged up or....

The coolant color and fill level in both the radiator and overflow tank will tell many things!

Those cars in the UK were deadly bombs'
Our alert for you is just as real
better safe than on the subway!

 

TL.00.32

Does the passenger side fan on the radiator come on with the AC on?
It should- look there first- often the connector gets dirty or the fan motor quits
Dirty connect can also lead to burned wired and - not good and has happened to a few here recently.
Use CRC Electrical spray contact cleaner or your fave brand when removing anything electrical and spray it good and clean

 

Thermostat is a very inexpensive part. If it is bad it can cause many bad things. Sometimes it exhibits interesting symptoms.
Fans don't turn on until car gets real hot; sensor right? Thermost will do that. Sensors actually seem to last quite a long time. Usually thermostats too, but if yours acts up again, say you don't notice. Well, all of a sudden no coolant circulating, no heat exchange = #1 way to ruin an engine - OVERHEAT.

Do yourself a favor and change it out.
Even with dirty coolant, not that it is good, but if it is full it should still exchange heat fine. Besides, when you change the thermostat, it is a perfect time for a coolant flush/fill.

 

My fan runs a lot and well before the guage is thinking of moving above its mark
Which one of us has a bad something?

 

Well, if your fan runs a lot, it is simply circulating cooler air through the radiator. Obviously when you are sitting and not moving, no air is flowing through radiator fins, so therefore the fans must do it (but you should stick your head out when your driving and listen to see if they work then too! lol J/k bro). So fans running often is good.
If your fans aren't running when they should it may be easy to think "oh, it is my sensor" which there should be a couple, one for the gauge and one for the fans, but I am not certain on this model. However, many a time I have seen a bad thermostat not allow the water from the head to travel into upper hose, sensors and therefore not trigger the fans or temp gauge until "HOLY $HI_ this thing is hot" and they then kick on once the thermostat finally opens.
So I would say, you have no problem.
Fans may work perfectly and if you test it by flipping on the A/C, that is circumventing the problem. Diagnose with the A/C off. See at what point do the fans kick in on their own. Watch the temp gauge all the while, and if all of a sudden the temp is hot and they kick in, I would put money on the thermostat.
Try that out bangumandoo. Let us know.

 

Ahh bd I misread your prior post- stupid old eyes!
The reason I suggest turn on ac is to verify power and operation to both fans

 

well i realized that the temp goes up when driving slow or at idle. but whenever i pick up any speed, it goes back to normal. fan problem?

 

The temp should should remain rock solid at 1 mark below halfway-
hills, AC on, traffic, whatever

If it ever does anything else there is a problem, all the things work
together to make that happen

When driving slow or idle- the fans come on to subsitute ram airflow thru the radiator

We really need to know the color of the coolant and if it was full- see if there is a leak
Then check the upper hose temp when engine at normal running temp
Careful!! it should be hot 200 degrees- if its cold that means the warm stuff in the engine is blocked behind the thermostat and cant get to the radiator to be cooled off-
means the thermostat is bad- replace

the sometimes ok sometimes not- and the it once went full hot- I have to agree with bibledriver on this one

 

Also could be plugged radiator- when you increase the engine speed
the water pump speed up too, so you may need a water pump after all!
Thats due at 90 if you have a 99 and 105 if 2000 or later,
you replace it with the timing belt

Also you can drain a liitle coolant from the radiator at the bottem and see what it looks like. Crud is bad!

 

seems like when i do rev it in neutral the temp goes down. your pinhole theory is correct so far. all i gotta do is replace the hose? which one?

 

when it happened to me it was my upper hose. also make sure that the hoses are completely sealed to the engine.

 

If thats the case then it would be the hose with the leak...

 

If it gets better with rpm you may be looking at bad water pump or clogged radiator
The pump is due for replacement at 90 or 105k miles depending on your year/model

A parts store will loan you the tool or do a pressure test on the cooling system for you- they place a special cap on the radiator and pump it up just like it was running
Where the water comes out- thats the problem!
Any green fluid on the ground under the car?

 

One more time=Change the Thermostat. Nothing else would make the car temp. guage red line then be ok again after cooling down. It's sticking closed! if only on occation.

 

It is cheap and easy. However, the pressure check won't hurt.

I had a pinhole leak on an old honda for about a year before I found it. The car never overheated though. For it to affect your car, the pressure would have to be lower (constantly) than it should, allowing the coolant to boil (steam hot = bad).

So, I am still leaning toward thermostat. No pride though, want you to get fixed. Pressure test is even easier than t-stat.

 

Hey BD

I was under the impression (old school) that if you have loss of pressure- the coolant wont circulate properly, you still get some flow but not at the same rate.
The guage could read normally but the cooling isnt really happening
It was the old days ways of leaving the radiator cap on but loose- to get home in an emergency with a bulging or pinholed hose or other unknown leak.

And the pressure test is free at the parts store- they loan you the tool which you stare helplessly at --- often better to have your girl do this for you- then they go outside and test it for you. Engine/coolant needs to be cool for this test- must remove radiator cap to do it-

CAUTION : WARNING : LIABILITY DISCLAIMER
HOT coolant rushing forth from the radiator/cap WILL cause a ~minimum~ of
2nd degree burns to the torso and neck- total bummer

 

TL,

Can't say you are not right. Trying to think of fluid dynamics and apply what a pinhole leak could really do to circulation. I can't seem to come up with a logical way to say that a pinhole leak could disrupt flow enough to speak of, unless it was bigger, at which point you would notice it. This IS just my logic, though. Certainly advisable to inspect for leaks. However, I completely agree, with the less pressure so as to not blow your fat hose.

If it were my car. . .
1. pressure test (free, quick, and easy). If bad, fix leak upon finding it. If not normal -
2. T-stat (cheap, kinda quick, kinda easy depending on level of confidence/experience) and concurrent flush and fill.

Question. . . Is your overflow consistently active? e.g. is your radiator always full when you remove the cap, and does the expansion tank work as designed? e.g. does it stay moderately at predictable levels given the temp of the engine?
The system is sealed and pressurized. If these two questions are not both yes, then your sealed system has some leak.
On the more obvious side, do you have to fill your radiator or tank ever?

 

My bad- was over-thinking the leak theory and dynamic pressure yada yada

Where is bang- the OP- with the latest on this?