[DaveA]

The standard temp gauge in my car is U/S, but it has a new sensor.

Rather than mucking anout trying to fix the standard gauge, I think I might install an aftermarket replacement.

Any suggestions as to a good gauge that will utilize the existing sensor?

[Gwagensteve]

I don’t believe you will find a gauge that works with the existing sensor.

I dislike aftermarket temperature gauges- most people have no idea what number constitutes a problem, whereas the stock instrument is really just a loose indicator of “normal” and “abnormal”

[DaveA]

Yeah, I see your point, but if the standard sensor has been replaced & the gauge still isn't working, I'm at a bit of a loss as what to do next.

To my way of thinking, a working gauge of whatever breed is going to be better than no gauge at all

[sideways]

Gwagensteve wrote:

I dislike aftermarket temperature gauges- most people have no idea what number constitutes a problem, whereas the stock instrument is really just a loose indicator of “normal” and “abnormal”

5 minutes googling could reveal that and a bit of red tape/paint on the gauge makes it clear if other people drive your car. Many gauges have programmable alarms now, that the way I would go. Then it's idiot proof and I don't know about you but I tend to not pay much attention to the gauges unless I've been having a problem.

I've got an aftermarket gauge on mine, it's a saas. I like this gauge because it has a 270 degree sweep and 2 degree graduations. No alarm though. The stock sender is 1/8 npt, the same as virtually all aftermarket gauges.

Since fitting the gauge I've seen the car slowly gets hotter when left to idle and the thermostat opens about 10 degrees earlier than it's meant to. The standard gauge didn't show either of those issues. In my experience stock gauges are practically useless and don't show a problem until it's too late. I've had overheating problems with almost every car I've owned and since having decent temperature gauges I haven't boiled anything over. IMO it's an extremely valuable tool for chasing cooling system problems.

[bumstein]

sideways wrote:

In my experience stock gauges are practically useless and don't show a problem until it's too late.

Agree they are roughly indicative only, I tend to find smell a good indicator too. I can smell the motor warming up but the gauges should show this up too if they work well.

Aftermarket gauges might give you a more accurate reading but make sure you know what it’s telling you. Small fluctuations may be normal, but I’m sure you’d get a feel for what the car is telling you

[MrRocky]

Ive found the stock gauge fine even with the 1.6
If your cooling system is in good working condition your temp should never move. Once you start adding non genuine or modded ("improved") bits then things start to head south.
If you gauge reads 1/3 consistently then if it moves you know you have an issue in the system. Its not needed have a super accurate reading, only to have an accurate baseline with which to monitor the system. You can check periodically with infra gun to make sure its all within spec.
Id trust a stock gauge over a saas/aftermarket setup anyday.
Bet u the aftermarket one wont last 200,000kms +

[Gwagensteve]

MrRocky nails it.

Everyone bangs on about the stock gauge being "inaccurate" when that's not it's job. There's "normal" and "abnormal" and that's all that matters. Lots of cars no longer have a coolant temperature gauge at all (BMW's haven't for years) They have a warning light. Because that's all, in reality, you need.

When I ask what temperature, in degrees, would result in you stopping/driving differently or what would constitute a "problem" and I think most people would struggle to answer unless they've already boiled a motor at figure X and then aim to stay below that figure. As Bumstein points out, you can normally smell/feel when the motor is getting hot.

My own car is terribly over cooled. My (stock Vitara) gauge tells me when the thermostat opens and when the fans come on. I didn't need the gauge to tell me when my electric water pump died and cooked the motor, it was quite apparent.

[fordem]

DaveA wrote:

Yeah, I see your point, but if the standard sensor has been replaced & the gauge still isn't working, I'm at a bit of a loss as what to do next.

The general concept is to diagnose the fault and then replace the defective part - not replace the suspected part and expect the problem to be fixed - which approach did you take?

The temperature gauge circuit on the G13 is one of the simplest things to troubleshoot - it's literally the gauge the sensor and the wiring - the gauge gets it's power from feed in the cluster that powers the fuel gauge and several warning lights, so once those are working it's unlikely to be a power issue, it's grounded via the sensor to the engine block, so grounding is rarely an issue.

The first test is to connect a low wattage 12v bulb (a park lamp bulb can be used) in place of the sensor and then switch the ignition on so you can see if the gauge responds, if it doesn't you check the wiring make sure it's good, and then you can change the gauge itself.

One last thing - there may be as many as three sensors near to one another - one (a 2 wire one) if you have EFI, a second (1 wire) if you have a/c, and the third (also 1 wire) for the gauge, did you replace the correct one, and did you replace it with the correct part?

[DaveA]

I've just recently purchased the vehicle and the vendor told me he'd replaced the sensor. That's all that's been done so far apparently.

She's a carby model & doesn't have A/C, so nice and simple

Thanks for the trick with bulb - I'll give that a go.

[sideways]

Gwagensteve wrote:

and cooked the motor.

Which is exactly the point. Wouldn't it have been better to not cook the motor? I agree an idiot light/alarm is all that's needed if you've got a perfectly functioning cooling system (and I'd certainly argue it's superior to a basic gauge of any sort for preventing a boilover) but the stock gauge is slow to react, I've had mine boil over before the gauge even moves (several times!).

Of course, if you are having cooling system troubles then an aftermarket gauge is extremely valuable for finding the issue. That's the reason you might want an accurate gauge.

No one is saying "u must replace stock with aftermarket hurr durr". But given a dead/questionable stock gauge (like the OP) I'd fit an aftermarket one.

[MrRocky]

All of my factory gauges have been quite accurate.
Bare in mind once you loose a certain amount of coolant your gauge will read lower or can even read cold.
When doing the baleno swap you splice into the temp sensor to get a reading, however it reads lower on the gauge than the sierra sender would (Say by half). This doesnt mean the gauge is inaccurate just the baseline temp reading on the gauge has moved. It can be difficult to pickup on initially.
I dare say i would be incline to use another zook model sender and adjust my perception of normal operating temp on the gauge.