Running Hot

Hey y'all
So noticed today that my thermostat was a hair higher than it normally is. I checked the coolant and Im about half full, would that make a difference? I am topping it off once it cools down. Maybe I am paranoid but the gauge is slightly above halfway which is where its always been. Any ideas or reasons to worry? Thanks!

 

Looks normal?

And by "half full" you mean the tank was half full? cause its not supposed to be full

 

It's been said on here before. That's an idiot gauge. Once it gets near / at / above H, it's too late.

From the tachometer and white background on the gauges, it looks like you have a 2001-2004 Tacoma SR5...

Do yourself a favor and buy a Scangauge, Ultragauge, or WiFi/Bluetooth OBD II reader and use it with a phone app to get an actual temperature reading on the coolant.

If you have an automatic transmission, you can also program that in and see the temperature of the transmission fluid.

 

1. What are your truck specs? 2.4,2.7,3.4?
2. When you say "half full" are you saying in the overflow tank or the actual radiator ?
3. That gauge is somewhat accurate so if its slightly above half way its a little warm for sure....I have messed around with a scan gauge and that needle...
4. any hard starts or rough running? CEL on?

Good luck

 

Does the needle on the gauge normally sit a little above the middle mark like that? I know some people claim that there's does, mine has always sat dead center.

Any way about it though, you won't know if you're actually running hot or not unless you get an accurate temp reading. Pick up an OBDII plugin off Amazon for a few bucks and download the Torque app on your phone, you can read your coolant temp along with a lot of other good info.

I've gotten my truck up to about 208˚ pulling up long highway grades with a lot of weight in the back, and the dash gauge stays dead center. So when it starts to climb you are already getting into dangerously hot territory well before it hits the red mark.

 

As long as you aren't hearing any coolant sizzling/boiling when you pop the hood you are probably not getting "too hot", but I would still start by getting an accurate temp reading before trying to diagnose anything. For all we know it might just be that your gauge is wonky and the temp is fine.

 

wow! thanks for all the insight so fast! the reservoir with the markings looks to be the half notch..and as far as the thermostat I recently noticed it looking a hair higher..
I have an 03 v6 tacoma 3.4l. What is CEL? best/cheapest scanner I should get?

 

CEL stands for check engine light.

Cheapest way to scan codes and read information from the ECU is to get an OBDII plugin from Amazon and use the Torque app on your phone. The plug in sends data via bluetooth to your phone and the Torque app displays the info on your phone.

Other option is to get an Ultragauge or Scangauge that plugs into the OBDII port under the dash. Those gauges mount to your dash and the info is displayed as you drive

 

got it thanks. How’s the

$60 Foxwell NT301 OBD2 Scanner Live Data Professional Mechanic OBDII Diagnostic Code Reader Tool for Check Engine Light

Foxwell NT301? $50 isn’t bad

 

Havent' seen that one but the reviews look good

 

That temp is dead spot on it is not hot it's normal Red is not pull over and let it cool off other than that drive home.

 

These engines will overheat well before the dash gauge hits the red mark.

 

Point is you can't go off the dash gauge, especially if you're trying to diagnose a possible issue. The variance in coolant temperature relative to the dash gauge is anything but accurate

 

Ok ill have that OBDII tomorrow, thanks Amazon. Kinda nervous... but I guess first step is to see whats going on

 

Welcome to TW.

 

Someone who thinks that the temperature reported by ECU is any better than the "idiot gauge" may be disappointed. Both sensors are basic type (thermo-resistors) with accuracy so-so. The purpose of the Coolant Temperature Sensor connected to ECU is to tell ECU when the engine reaches the "Normal Operating Temperature" so it can come out of the open loop. It is just a tad better than on-off switch as it tells the ECU when the coolant temperature goes above few predefined thresholds at which the ECU lowers the idle rpm. That's it. ECU does not care if the temperature is 180 or 190F - as long as it's above 180 it's good Normal Operating Temperature. So the sensor can be few degrees off the calibration with no real impact on the engine performance.

The other thing is that that both sensors depend on the coolant flowing through it, so if coolant flow is stopped or restricted it will not tell you the failure on time. When the water pump stops the temperature on cylinder walls and head will be over the roof before the temperature sensor (either one) tell you something is wrong. Really the only real use for the dash needle is to tell you when you can start opening cabin heat valve - when the needle starts moving the slightly warm air will start coming in.

I had similar issue with the gauge which on the other hand started to show slightly lower temperature that it was. I understand the pain of this thing being annoying. After verifying from the other sensor (reported by ECU) that there is nothing wrong with the engine, just the sender started to act I just replaced the sender and everything went back to normal including my OCD

 

If that were the case, I would think you'd have class action lawsuits all over the place against Toyota. That would be straight up negligence to have a "warning indicator" that doesn't actually warn you. Like a WWII air-raid siren that only goes off after the bombs explode.

If it's anything like my trans temp sensor, even if the light comes on, you're not necessarily F'ed. One time towing a trailer up 50 I felt the trans get hot through the floorboards. Warning light never came on, but the fluid is fine (no cooked smell, color is good). Same thing with my 4Runner. trans temps got up to 240 or so (from obdII) and warning light never came on. Maybe it would have if I had sustained that temp for longer, but it was only a couple minutes. Again, trans fluid is fine.

@Jonah.sloven if the reservoir has coolant in it, that means it bubbled over from the rad, which means the rad is now low on coolant, and that needs to be addressed. That's definitely evidence it has overheated, but that doesn't mean your engine is bad, unless you just kept driving it like that.

The other folks are on the right track here, the OBDII may help diagnose the problem, however I'd at *least" re-fill the rad and make sure there are no air bubbles in the lines ("burp" the rad). There are many possible reasons for overheating, time to start ruling as many out as you can.

 

Could be worse. U gtg bro.



Nah but seriously my gauge used to be dead center but after hg, head, and ECT sensor change my gauge sits where urs is so I wouldn't worry as mentioned.

 

Have you hooked up a ob2 scanner and watched your engine temp? I believe its suppose to be 180-200 range or somethinf i had a problem with my thermostat stuck open and my engine temp stayed around 136 degrees

 

Your local autozone will make your borrow a scanner for free no charge