Has anyone found an interchangeable temperature sender from another vehicle that will make my 98 Forester's gauge read coolant temperature accurately.  It now is like the famous Ford "dummy" oil pressure gauge in that my temp. gauge seems to read in mid-range anytime the coolant is anywhere from mildly warm to near meltdown.  I'd like to see it actually read like some other vehicles do, fluctuating when the thermostat opens or closes, varying under load, and so on.  As near as I can deduce, the temperature sender does not send a proportional signal to the gauge but is weighted heavily "mid-scale".   I'd like to think that a sender from some other application would fix my frustration.

the thermostat and fans are supposed to work together to keep the temp very stable.

 

you'd do better I think to investigate an analog gauge or , if you have a smartphone, there are adapters and apps that could give you temp and other info on your phone. Find a vent or other mount for the phone and have a 'configurable' gauge/readout.

elm 327 BT adapter and Torque app probably has a function that would work.

Other folks here have experience with stuff like this to help with specifics.

Edited February 1, 20179 yr by 1 Lucky Texan

The dumb factor might be in  the gauge vs the sender.

Yes, the sender *should* give a very linear resistance range through the temperature range. It is the gauge that tries to compensate for minor fluctuations and only read major problems.

 

 

If you want more resolution, it'll need to be an aftermarket gauge of some sort.

Scan guage so you can see the digital temp readout from the ECU, or just hook up and old school mechanical guage. The temp sensor is the same as any other car, the guage is where the circuitry is that affects how the needle moves.

 

The coolant temp really doesn't vary that much during normal operation. These engines warm up quickly and maintain a fairly even temperature regardless of load. In my experience, when they do run hot the guage reflects that, except if the coolant level is low. But if your having an overheating problem no guage is going to fix that.