Temperature Gauge ?

[Swifty75]

Hi All

My Stag's temp gauge goes up to about 7/8ths just before the red, this is usually when I am going uphill. I have changed the coolant and flushed the system etc, but it still goes up there and it worries me!

Today when I got home, it was 3/4s on the gauge so I thought I would check the overflow bottle. This was half full as always, there was no pressure against the cap, I could even put my finger in the coolant and it was luke warm. I then removed the brass radiator cap/bolt and there was no explosion of water like it was under pressure. Again it was hot but knowhere near boiling. The car has an aftermarket electric fan with a guage that allows you to turn it up and down. When I turned it down it went of at 60 which would suggest this was the temp of the water. This leads me to believe either the temp sender or gauge is incorrect. Has anyone had this before and was it an easy fix?

Thanks Neil

[milothedog]

Hi All

My Stag's temp gauge goes up to about 7/8ths just before the red, this is usually when I am going uphill. I have changed the coolant and flushed the system etc, but it still goes up there and it worries me!

Today when I got home, it was 3/4s on the gauge so I thought I would check the overflow bottle. This was half full as always, there was no pressure against the cap, I could even put my finger in the coolant and it was luke warm. I then removed the brass radiator cap/bolt and there was no explosion of water like it was under pressure. Again it was hot but knowhere near boiling. The car has an aftermarket electric fan with a guage that allows you to turn it up and down. When I turned it down it went of at 60 which would suggest this was the temp of the water. This leads me to believe either the temp sender or gauge is incorrect. Has anyone had this before and was it an easy fix?

Thanks Neil

LD parts sell the correct sender., http://www.ldpart.co.uk/shop/shop.ph...37a71329268e18 if you want to get the gauge checked and calibrated get in touch with Alan at the gauge shop http://thegaugeshop.com/

[richardthestag]

Hi All

My Stag's temp gauge goes up to about 7/8ths just before the red, this is usually when I am going uphill. I have changed the coolant and flushed the system etc, but it still goes up there and it worries me!

Today when I got home, it was 3/4s on the gauge so I thought I would check the overflow bottle. This was half full as always, there was no pressure against the cap, I could even put my finger in the coolant and it was luke warm. I then removed the brass radiator cap/bolt and there was no explosion of water like it was under pressure. Again it was hot but knowhere near boiling. The car has an aftermarket electric fan with a guage that allows you to turn it up and down. When I turned it down it went of at 60 which would suggest this was the temp of the water. This leads me to believe either the temp sender or gauge is incorrect. Has anyone had this before and was it an easy fix?

Thanks Neil

Hi Neil

that it was 3/4 on the gauge and no pressure in the system is the clue I think.

System is not pressurising find the leak and report back

Also what Ian said ^^ standard sensors available these days can swing from mid to 3/4 on the gauge with a couple of degree water temp difference. I got so fed up with it that I fitted a capillary gauge. LD Part would appear to be a step in the right direction. with a system pressurised to 20lb boiling point should be the other side of 125centigrade

Also check that the tacho still has the earth wire attached else both temp and fuel gauges will overread.

[Swifty75]

I have done 150 miles in it and every time I look in the rad the water is right to the top, the bottle does not move either. Also I have sat in on the drive running for an age and there is no water loss onto the drive. The only other water loss could be into the engine through the head gasket but there is no sign of this either. Also as the water had not got to over 60 according to the fan, I am assuming that the reading is wrong on the gauge. Even when it gets to 7/8 just before the red there is no sign that the car is overheating?

I initially thought it must be losing water but it appears not to be.

[StagJonno]

It doesn't sound as if you're overheating, rather some issue with the indication.

Is the fuel gauge reading high also? This would point to a knackered voltage stabiliser, as both Temp & Fuel gauges are fed from this. Replacement voltage stabilisers are readily available for small money from most Stag suppliers including LD Part http://ldpart.co.uk/shop/shop.php?c=...8ed239c6430955 .It's located behind the instrument panel, mounted on the back of either the speedo or tachometer (can't remember which, offhand). Make sure the voltage stabiliser is mounted tightly and that the speedo, or tacho rear can is earthed. Also agree with Richard's recommendation for a replacement temp sensor from LD Part. Peter there makes sure the ones he sells will give a vertical needle at 90C http://ldpart.co.uk/shop/shop.php?c=...x=19&image.y=7 .

Jonno

[milothedog]

I said about getting a new sender from Peter in post 2

[StagJonno]

So you did. You didn't mention that Peter @ LD sold calibrated sensors rather than the fairly random ones from other suppliers. Anyway, imitation is usually taken to imply flattery

[KOY 23]

There’s a lot of imitation tonight as Richardthestag had already suggested to check the voltage regulator and it’s earthing

[marshman]

There’s a lot of imitation tonight as Richardthestag had already suggested to check the voltage regulator and it’s earthing

Richard suggested checking the earth, he didn't mention the regulator

[Swifty75]

Could it be that either the water pump is not working, or the stat is stuck shut? I would have thought that would cook the engine very quickly. I have ordered a sender so will see what that does.

[dasadrew]

C'mon guys, if 2, 3, or more people make the same recommendation or variations thereof, does it matter? It's not a race to see who gets to share his knowledge first.

Drew

[dasadrew]

One of those Chinese IR thermometers off eBay could give you some factual information about the actual temperatures around the engine. There have been a few posts citing the transfer housing measured temperatures.

Drew

[thebadleys]

Water pump not working seems unlikely as I think there would be serious consequences, thermostat stuck closed, I would thought would pressurise the system.

It does sound, as has been previously suggested, to be sender/gauge related, if the sender doesn't cure it I have a spare gauge that you could try, it was calibrated before I fitted a capillary gauge.

Nigel

[richardthestag]

My Stag's temp gauge goes up to about 7/8ths just before the red, this is usually when I am going uphill.

In addition to a poor temp sendor and / or unearthed voltage stabiliser as already mentioned by many

A blocked rad could cause this symptom, as could a mk1 stat in a mk2 inlet manifold. In fact any compromise of the cooling system aint going to help.

Today when I got home, it was 3/4s on the gauge so I thought I would check the overflow bottle. This was half full as always, there was no pressure against the cap, I could even put my finger in the coolant and it was luke warm. I then removed the brass radiator cap/bolt and there was no explosion of water like it was under pressure. Again it was hot but knowhere near boiling.

This ^^^ IS NOT RIGHT, the cooling system would appear to be unpressurised. regardless of the gauge this is NOT GOING TO HELP and will need addressing.

Nobody has alluded to ignition yet either. I appreciate that Neil can dunk his finger into the coolant when the gauge is reading 3/4 so is unlikely to be the issue. BUT for completeness of the thread and if anyone else is experiencing similar issues but WITH a pressurised cooling system. poor ignition timing or failed vacuum advance will cause engine to run much hotter under load that it should do

As you were etc

[milothedog]

Just to add a bit more useful information, here is the Bosch industry standard resistance range for a Thermistor should you wish to play around testing one. Probably of no use if you have a nasty Chinese copy though.......