Coolant temp gauge idea...

[FunElan]

Hi all,

In an effort to "idiot-proof" my Elan, I'd love to convert the clock to be a digital water temperature gauge. My dial in the cluster seems to take its sweet sweet time rising, even when I've verified with ElanScan that coolant temp does indeed rise. I basically use oil pressure to ensure that my car is up to operating temp (not that I'm getting on boost until oil pressure lowers...)

I can likely find a screen that fits where the clock goes. I see many generic temp gauges online, which would require splicing a hose and inserting a fitting inline. To simplify things though...would it be possible just to find a probe that fits in the fitting for the existing gauge temp sender and use that? Existing gauge is almost useless for me anyway, so I could just rely on the digital gauge instead. It seems like too simple of a solution, so I need someone to poke a hole in this

[Tuga2112]

geoffsmith has made something to adapt the cauge in the cluster to act more like you are used to. i know ive seen the post somewhere in here. its probably more than 8 years old... or more than 10... i think its been here before i became a member.

but my point is... theres a solution already in the forum. following it is not very straighforard. but some of yhe legwork has been done already

[FunElan]

geoffsmith has made something to adapt the cauge in the cluster to act more like you are used to. i know ive seen the post somewhere in here. its probably more than 8 years old... or more than 10... i think its been here before i became a member.

but my point is... theres a solution already in the forum. following it is not very straighforard. but some of yhe legwork has been done already

I've seen that solution. The one to "linearize" the gauge? If so, that's not my problem. If I installed that mod, my needle would still be slow. It's not an issue with me reading it like other cars. I'm okay with the sweep. I don't know how to be more clear. The needle moving up when sitting in traffic is fine.

My gauge is slow to respond upon the first drive of the day. I want real time data as to where my coolant temp is. Every other car I have (with good grounds) does this effectively with a needle. The Elan doesn't. Perhaps my chassis ground could use fettling, but I'm trying to baseline this car and make it as usable as possible for me. I don't see a world in which the gauge "pops up" to the current temp when the key is turned. Does yours do that? If so, then I should start somewhere else. If your gauge is slow to rise like mine, well....that's why I'm considering this PROBABLY EASY mod.

[FunElan]

I'm going to make this abundantly clear:


My issue is that upon the first startup and drive of the day, the gauge and the engine are not even remotely near each other. It's almost as if the gauge itself is "Warming up" and moving slowly, thereby giving me incorrect readings according to ElanScan. It's a confusing one to understand.

Once I start it up for the 2nd time in a day, after it has been driven, or the weather is warmer, the gauge moves to the 1/4 spot fairly swiftly, and then begins its dance up the scale as traffic allows.

[Tuga2112]

I would be checking the location of the sensor in relation to the coolant flow, and thermostat location and the other coolant sensors. if i recall correctly. there are 3 "sensors" tracking the coolant.

the first is not actually a sensor. but just a switch. used to activate the radiator fans
the second is the one that reads to the instrument binacle
the third is the one that reads to the ECU

if i had your consern, i would be
1 -confirming this assumption to be right,
2 - if so. (i am 90% certain) pay close attention to the location of sensor 2 and 3 and how they are located as far as the coolant flow and thermostat operation affecting them.
3 - plug elanscan to the car and track its value, and compare to the needle in the binacle.

and onl after confirming the issue is what you think,
im sure you can tap another wire to the existing sensor (of your choice) and put a LCD display with a numeric value in the dash.

i am just trying to rule out the possibility that the binacle readings are taken from a location in the flow that is only warmed up after the thermostat opens. which would give you a "delayed" response by nature. (which also means your digital reading would still be "slow" )

[FunElan]

You are correct, there are 3 sensors/switches in the thermostat housing. The one for the binnacle connection is called the "temp gauge thermal sender" in the manual.

I'd be shocked (but I guess not that shocked?) if the temp gauge from the factory didn't operate until the thermostat opens. Either way, I've verified my gauge against ElanScan. The car got to operating temperature, but the dial hadn't moved. Later that day, the gauge was operating as normal. It's consistent, and that's my issue. I don't want to be surprised one day if my fans decide to not kick on.

I have a feeling if I tap an existing wire, it would change resistance of the sender and perhaps might not read correctly on any gauge? This is why I came here, someone else should know!

A number of products like this are on the market: https://www.google.com/search?sca_esv=f ... =apv&pvs=0

My thought would be to find one that has the same thread pitch as the factory "temp gauge thermal sender" and find one with a small enough screen that I can repurpose into the clock area.

[Tuga2112]

i dont know about the LDC stuff your talking about. because my experience with electronics is extremely specific.

1 - Ive altered the wiring on the car to bypass the the radiator switch (as per someone else's post back many years ago)
i wouldnt call that electronics

2 - installed a buzer in the passenger side to remind me the light are on when the doors open (you will find a group buy for it... which noboty was interested in)
electornics to a very lesser degree... as it took some knowledge to figure out the right way to make it work

3 - replaced a blank button in the dash with 3d printed fast usb charger, getting hte power feed from the cigarrete lighter (is still in progress...)
not electronics

4 - required digital clock and radio to have the ISO plug with as many signals as i practically could to make the radio operate to the same degree as in a modern car
more advanced stuff.. but not electronics...

5 - installed LED lights.. by figuring out my own circuitry for the pods delay module bypass... (anyone could copy what has been stated in the forum elsewhere... i just implemneted it my own way)
similar complexity to 4 and 2

6- installed a generic remote locking box...
just a few wires cut and crimped.. not any more complex than 3

7 - created a little box that is connected to the central locking, as well as tapping into the 4 relays that control the windows..
now that i would call electronics. as there is an arduino brain with my software running it. hall effect sensors ensuring the motors are not burned. optocouplers to recognise the switches being triggered as well as the signal value from the central locking.
the box makes the windows control be a "single tap to fully open/close" and it will open the windows a tiny bit when unlocking the doors (seals wont rub when opening the door) and close again 5 minutes later and when locking the doors it will completely close both windows

now. based on the experience in developing 7.. i can tell you my arduino recognises the signal from the lock circuit without causing the system to mal funciton. its there purely for the purpose of tracking the voltage in that wire compared to a comon ground.

i know the arduino can do that both on a digital manner as well as an analogue maner (different pins). and if i was trying to make my own LCD instrument cluster. i would not hesitate to tap into both sensors and just report the number from both in the LCD...

however you can easily test the scenrio. tap into the wire with your sensor start car disconnected, and check reading. stop car. and connect. check if elanscan reading dropped considerably.

keep in mind the vltage will drop when the engine stops. so what your comparing is the warm value with engine stopped before and after attaching your LCD display

[Giniw]

I'm going to make this abundantly clear:


My issue is that upon the first startup and drive of the day, the gauge and the engine are not even remotely near each other. It's almost as if the gauge itself is "Warming up" and moving slowly, thereby giving me incorrect readings according to ElanScan. It's a confusing one to understand.

Once I start it up for the 2nd time in a day, after it has been driven, or the weather is warmer, the gauge moves to the 1/4 spot fairly swiftly, and then begins its dance up the scale as traffic allows.

Hi, I'm still not quite sure to understand: the way I see it, the needle is not moving before the water reaches a minimum temperature, let's say 50°C (no idea if it's the actual minimal temperature), so assuming the ambient temperature is 20°C when you start the car in the morning, it won't move for a while until the water temp reaches 50°C.
=> if the needle is bottoming out, the engine is cold and you don't even need to know the exact temperature: it's too cold to be driven hard anyway.
(Of course you may still want to know, but a normal owner would not care all that much, like the voltmeter doesn't go as low as 0V either)

That being said, maybe I did not understand your issue at all

[FunElan]

I'm going to make this abundantly clear:


My issue is that upon the first startup and drive of the day, the gauge and the engine are not even remotely near each other. It's almost as if the gauge itself is "Warming up" and moving slowly, thereby giving me incorrect readings according to ElanScan. It's a confusing one to understand.

Once I start it up for the 2nd time in a day, after it has been driven, or the weather is warmer, the gauge moves to the 1/4 spot fairly swiftly, and then begins its dance up the scale as traffic allows.

Hi, I'm still not quite sure to understand: the way I see it, the needle is not moving before the water reaches a minimum temperature, let's say 50°C (no idea if it's the actual minimal temperature), so assuming the ambient temperature is 20°C when you start the car in the morning, it won't move for a while until the water temp reaches 50°C.
=> if the needle is bottoming out, the engine is cold and you don't even need to know the exact temperature: it's too cold to be driven hard anyway.
(Of course you may still want to know, but a normal owner would not care all that much, like the voltmeter doesn't go as low as 0V either)

That being said, maybe I did not understand your issue at all

I don't think you understand the issue and that's okay.

Here's the "WHY" I want to do this. The way I track engine temp lately, after my first startup, is by using the oil pressure gauge as an indication of engine temperature. PV=nRT (anyone else remember this from chemistry?). I still don't drive the car hard until I know it's fully warmed up and oil pressure isn't so high.

The purpose of this idea is to have an immediate idea if coolant/the engine is up to temperature at any given time. This does not currently happen with my (or any of your?) gauges in the binnacle. This is only achieved through Elanscan. When I turn the key in any of my other cars, INCLUDING a 1969 Elan with a capillary gauge, I know what the water temp is IMMEDIATELY.

SO....I didn't come here to debate the problem . Just to discuss if my solution is viable.

[M100Brisbane]

I know this won’t fit in any of the spaces on the dash, but…

I have them in my Land Rover TD5 and my Lotus Europa. Easy to install, no messing with the coolant, and remarkably accurate and responsive.

Plus you can set an overheat alarm.

https://engineguard.com.au/?gad_source= ... LgEALw_wcB

[Giniw]

When I turn the key in any of my other cars, INCLUDING a 1969 Elan with a capillary gauge, I know what the water temp is IMMEDIATELY.

SO....I didn't come here to debate the problem . Just to discuss if my solution is viable.

Ahhhhhhhh, OK now I understand
You meant the gauge/needle is not responsive enough ^^

[FunElan]

I know this won’t fit in any of the spaces on the dash, but…

I have them in my Land Rover TD5 and my Lotus Europa. Easy to install, no messing with the coolant, and remarkably accurate and responsive.

Plus you can set an overheat alarm.

https://engineguard.com.au/?gad_source= ... LgEALw_wcB

Interesting concept...measuring cyl head temperature as an indicator. Never thought about that. I wonder if cyl head temp is consistent on every side of the head? I could adapt their sensor to my own gauge...

When I turn the key in any of my other cars, INCLUDING a 1969 Elan with a capillary gauge, I know what the water temp is IMMEDIATELY.

SO....I didn't come here to debate the problem . Just to discuss if my solution is viable.

Ahhhhhhhh, OK now I understand
You meant the gauge/needle is not responsive enough ^^

It's SLOW, and if I look at the temp gauge, it may or may not be right. To me, that is unacceptable in a car which tends to run hot and has minimal cooling areas in the front end. My BMW doesn't even need an electric fan.

[Fredjohn]

Funelan..
Just a small reminder that the Elan was thoroughly tested in Death Valley and the cooling was proven to be more than adequate. Any issues now are due to the cars being 30+ years old.
Doesn't help with your gauge though!


But I do agree the gauge was not well engineered.

[FunElan]

Funelan..
Just a small reminder that the Elan was thoroughly tested in Death Valley and the cooling was proven to be more than adequate. Any issues now are due to the cars being 30+ years old.
Doesn't help with your gauge though!


But I do agree the gauge was not well engineered.

Haha, it is a good reminder. So far, it's been stellar (after I replaced the thermostat). My emissions tester left it idling for 20 minutes straight and it was fine. BUT....I like preventing problems