Coolant Temp Gauge - Could it be more accurate?

From what I know and read about the coolant temp gauge in the 1st Gen, it is just an "idiot gauge". It doesn't actually move in real time with the ups and downs of the coolant temp. If it is in operating range, it stays steady at about half way up. The only time it will go above this, is if it is too hot. By the time that happens, you are already overheated.

I know people add scangauges or dedicated gauges to display this information. I would love to have A/T Oil Press and Temp gauges as well as engine oil press and temperature. Thinking about adding these in somehow, but it would be great just to get the original gauge to read accurately.

My questions are:

• How does this gauge work? As in what drives the needle to move from Cold - Operational - Hot?
• Could this be hacked to display "true" relative temperature and what is involved to do so?

Thanks for you help!

 

by the time it moves into the danger zone your already at or past head warping temps. just easier to get a scangauge

 

Thanks, I don't doubt it's easier to just add the scan gauge. My questions still stand if it can be done though.

 

I know the LC guys add resistors in the circuit to show a larger sweeping range, you could probably apply this same technique to the Tacoma but may need to experiment with different resistors.

https://forum.ih8mud.com/threads/93-97-coolant-temperature-gauge-modification.64252/

 

Same thing in the 80 series Land Cruiser. There is a mod to make it move with actual temp changes in the system but don't know if it works in the Tacoma. But in the mean time just keep up with coolant maintenance, water pump OEM thermostat, coolant, fan clutch and hoses.

https://forum.ih8mud.com/threads/93-97-coolant-temperature-gauge-modification.64252/

 

Anything is possible with enough cutting, welding, or soldering, lol

But IMO, a lot of work for little to no real benefit.

The temp gauge does actually read accurately. At least accurately "enough". People are dumb, so engineers stopped giving actual temps a long time ago. People add a scangauage, and then freak out when they see their temps vary by 10 degrees. People get used to the "temp" being 100% stable, which it is not. Obvious to some, but not the majority it seams.

It's helpful to know the actual temps (from OBD) for diagnosing an issue, but it's honestly unnecessary for just every day driving. I'm more of a fan of keeping your eyes on the road, than keeping track of a 5 degree temp swing.

 

All you do with a scan guage is plug it into the OBDII port. It can’t really get easier other than doing nothing.
Plus you get a lot of other features with a scan guage.
“Hacking” the stock temp guage would be vastly more involved.

 

Agreed, anything is possible. I enjoy working on my vehicle as much as driving it, so a bit of work is not a big deal to me. I think just by being on this forum, we are not most drivers. I would say people on this forum actually care about having this info, but I could be wrong. Regardless, I would like to know since I'm considering remote travel. IMO, a good amount of overheats don't happen suddenly. Knowing what the typical operating range of an engine would help you spot a developing problem and therefore, you could prevent an actual overheat condition. For daily driving and commuting, I agree that you really don't need the info.

Agreed and I might end up going down this route, just depends. I like the look of gauges and having a clean/factory appearance. The scan gauge is not bad looking, but definitely a bit out of place. I willing to put in the extra work if it means one less extra gauge I would install. I'm really just exploring options at this point.

 

Lots of great info here, thanks alot!

 

If you just use the scan gauage for temp just buy a universal water temp gauge for under $30.

 

The temperature sensors are just thermistors -- resistors that change resistance with temperature. You could just hook an ohmmeter to it and measure the resistance and convert that to temperature. This is what the needle gauge is doing, but it takes about a 20°F change to notice anything out of the normal. If the needle was more sensitive to changes, then when the engine was very cold you wouldn't see the needle move from the bottom until you were almost warmed up, so it's a trade off. A digital readout would be best, but that is basically what you'd get with a scan gauge using the OBD2 port.

 

Thats what the mod does on my LC, allows for incremental changes instead of only the large changes.

 

yes and no.

those long slow overheats can often be prevented with normal (and proper) routine maintenance and just knowing your vehicle. For those catastrophic failures (rad explodes for example), there's not likely very many clear warning signs. Detailed inspection of the radiator is about the only hope you'd have to prevent that type of thing. Yes, installing the t-stat jiggle valve wrong will cause it to run a few degrees hotter, but that's hardly "overheating" and won't blow your motor.

I agree that when we use our vehicles for "non-standard" operations (remote off road), it's good to know more info about your vehicle than what is typically given from the idiot lights. But all that still needs to be taken with a grain of salt.
As someone who deals with data analysis every day, ALL THE DATA isn't necessarily good or even useful. In fact, it's quite easy to come to a wrong conclusion when you are drowning in data. IMO this is especially bad when you're trying to drive a vehicle at the same time. People are distracted enough already.

 

Scan gauge would be great if it had a REAL GUI (Graphical-User-Interface). We're in the 21st century, and Scan gauge STILL has a readout that is right down there with the game, "PONG" that came out in the 80's.

 

Well sometimes simple works. That's why I like mine.