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I just got finished replacing my water pump, thermostat, timing belt, and tensioner, and now my temp needle almost sits on the slightly higher middle temperature line on the temperature gauge. Wondering if this is normal or whether something is wrong in the cooling system, because it USED to be how the pictured gauge is but now it sits about one line higher.
^^how it used to sit
This *can* be normal, yes. But it shouldn't go any higher than what you have described. Unrelated to your cause but I noticed the same behavior after I performed my GTE engine swap and did the minor wiring change to make my factory coolant temp gauge work again. I reasoned this must have been because the sensor on the GTE engine might be calibrated ever so slightly differently than the OEM SC300 gauge sender (or SC400 equivalent). Also keep in mind that these gauges can require some service over time (through Tanin Auto) if you ever notice a severe decline in their function.
But what you're describing is still pretty close to normal from the sound of it. If it ever goes any hotter than that on the dial then yes you should begin checking for anything that could cause overheating.
Also it can be related to your current climate. The gauge is designed to read fairly normally from full cold up to "operating temperature" and then is designed to sit in the middle reading continuously unless your engine gets REALLY hot into a potential overheat condition.
Stock cars do not need this but I installed a secondary real-time analog coolant temperature gauge in the ashtray location (using a replacement 3D printed bezel) which shows the accurate engine coolant temperature at any given moment whenever I need to refer to it. The sensor input location for me is the upper radiator hose with an aftermarket in-line coolant temp sensor aluminum adaptor in the middle of it.
Unless you're noticing anything abnormal as to engine behavior or on your stock gauge, so long as your needle is at the just-over-middle mark then you should be fine.
What you pictured is normal, I would say make sure to park on an incline and burp the coolant system with a lisle funnel kit with your heater on full hot with the fan on until the car warms up to release any possibly stuck bubbles in your system.
This *can* be normal, yes. But it shouldn't go any higher than what you have described. Unrelated to your cause but I noticed the same behavior after I performed my GTE engine swap and did the minor wiring change to make my factory coolant temp gauge work again. I reasoned this must have been because the sensor on the GTE engine might be calibrated ever so slightly differently than the OEM SC300 gauge sender (or SC400 equivalent). Also keep in mind that these gauges can require some service over time (through Tanin Auto) if you ever notice a severe decline in their function.
But what you're describing is still pretty close to normal from the sound of it. If it ever goes any hotter than that on the dial then yes you should begin checking for anything that could cause overheating.
Also it can be related to your current climate. The gauge is designed to read fairly normally from full cold up to "operating temperature" and then is designed to sit in the middle reading continuously unless your engine gets REALLY hot into a potential overheat condition.
Stock cars do not need this but I installed a secondary real-time analog coolant temperature gauge in the ashtray location (using a replacement 3D printed bezel) which shows the accurate engine coolant temperature at any given moment whenever I need to refer to it. The sensor input location for me is the upper radiator hose with an aftermarket in-line coolant temp sensor aluminum adaptor in the middle of it.
Unless you're noticing anything abnormal as to engine behavior or on your stock gauge, so long as your needle is at the just-over-middle mark then you should be fine.
Thank you for the information it’ll usually sit right in between the two lines and occasionally goes up to the second line but only where it’s half covering it but it never goes higher than that I might try burping the system
What you pictured is normal, I would say make sure to park on an incline and burp the coolant system with a lisle funnel kit with your heater on full hot with the fan on until the car warms up to release any possibly stuck bubbles in your system.
I’ll make sure to do this an update whether it’s changed thank you
This *can* be normal, yes. But it shouldn't go any higher than what you have described. Unrelated to your cause but I noticed the same behavior after I performed my GTE engine swap and did the minor wiring change to make my factory coolant temp gauge work again. I reasoned this must have been because the sensor on the GTE engine might be calibrated ever so slightly differently than the OEM SC300 gauge sender (or SC400 equivalent). Also keep in mind that these gauges can require some service over time (through Tanin Auto) if you ever notice a severe decline in their function.
But what you're describing is still pretty close to normal from the sound of it. If it ever goes any hotter than that on the dial then yes you should begin checking for anything that could cause overheating.
Also it can be related to your current climate. The gauge is designed to read fairly normally from full cold up to "operating temperature" and then is designed to sit in the middle reading continuously unless your engine gets REALLY hot into a potential overheat condition.
Stock cars do not need this but I installed a secondary real-time analog coolant temperature gauge in the ashtray location (using a replacement 3D printed bezel) which shows the accurate engine coolant temperature at any given moment whenever I need to refer to it. The sensor input location for me is the upper radiator hose with an aftermarket in-line coolant temp sensor aluminum adaptor in the middle of it.
Unless you're noticing anything abnormal as to engine behavior or on your stock gauge, so long as your needle is at the just-over-middle mark then you should be fine.
^^ Burping the system is always recommended if you've drained and refilled the coolant anyway so that's good maintenance. From your picture this is exactly how my stock coolant temp gauge looks in my SC.
However I must note again that for me this change from the needle being right in the middle only happened *after* I did a stock GTE swap to my car... and yours has a stock GE engine. Both JZ engine types (non-vvt-i) have a separate coolant temperature sensor that specifically sends a voltage signal to that cluster gauge and I have suspected that the are each calibrated ever so slightly differently... but not by very much. As I recall my swap may have required a specific resistor to be added in-ine to normalize the output voltage to the gauge. Or maybe I didn't have to do that in my case (USDM GTE for mine vs JDM GTE in other cases perhaps).
This change also may have occurred for me just a little before that when I installed a Koyo aluminum MKIV radiator till with my totally stock GE engine. I can't recall for sure as that initial change was many years ago for my SC.
But that side note out of the way this isn't the first time I have heard of a stock SC300 having its stock coolant temp gauge read slightly above the middle. Remember that Toyota engineers designed the gauge reading for peace of mind and comfort rather than second-to-second accuracy. The stock gauge isn't supposed to change its needle position once settled unless you are approaching a true overheat condition. And these are 30 year old gauges in some cases which occasionally do get serviced by Tanin Auto.
So as long as you are seeing a consistent reading on your gauge which does not go up and then back down again *after the engine has come up to fully temperature* then there should not be anything to be concerned about.
If you do want even more accuracy, which I can understand, then you would need to install a secondary coolant temp gauge with its own sender. Usually installing an in-line coupler in the upper radiator hose area is an easy way to get that. Or... if you have an aftermarket MKIV radiator installed and aren't using the lower fan sensor-switch location yet you can install a coolant temp sensor there as well.
07-14-23, 09:49 PM
Slightly high temperature on temp gauge
