Range Rover Temp Sender Thread Size?

[SILICONEKID 357HP]

If you go for a fully synthetic do you add a zinc additive?

[Sir Paolo]

Hi, not necessarily.

I use Fuchs Pro S 10w50, I can’t recall the exact ZDDP figure, but it’s about the highest you can get of the readily available quality oils (as recommended by Opie).

It’s also an ‘Ester’ fully synthetic oil, which means it is more stable than ordinary fully synthetics.

[LLantrisant]

Dougal9887 said:

That's correct. Pre interim manifolds have a different gauge sensor and it's mounted as below

Dougal.

TVR used an adaptor here, 5/8unf male to 3/8BSP female (sender is 3/8 male), bringing the sender out of the water flow, hence the low reading.

Does anybody now if ETB Instruemnts can supply a 5/8unf sender, matched to the temperature gauge?
i have checked their webpage, there is a sender listed, but no idea if it matches the instruemnts supplied to TVR.

[LLantrisant]

no, it doesnt work fine, as the sender is not in the water flow. due to the adaptor the sender is fully recessed inside the adaptor.
mine is a car with catalytic converter, but pre-serpentine.

Edited by LLantrisant on Saturday 20th June 11:04

[LLantrisant]

so i ask again: Does anybody now if ETB Instruemnts can supply a 5/8unf sender, matched to the temperature gauge?
i have checked their webpage, there is a sender listed, but no idea if it matches the instruemnts supplied to TVR.
i also contacted them,but no reply until now.

[Zener]

I've deleted my previous as they wasn't helpful for you

[MisterT]

LLantrisant said:

Does anybody now if ETB Instruemnts can supply a 5/8unf sender, matched to the temperature gauge?
i have checked their webpage, there is a sender listed, but no idea if it matches the instruemnts supplied to TVR.

ETB told me that the gauges known as ETB fitted to the Griffs and Chims around ‘94 were actually made by a different company that ETB bought up. The current range of ETB gauges and senders are not compatible with the gauges we have in the TVR. They couldn’t sell me a sender matched to my temp gauge.

I wanted a 1/8 nptf sender to fit in the tapping on the left side manifold runner near the ecu temp sender, they told me to use a Ford sender ref SNB108. This is a 1/8 nptf thread so if you use it you’ll need an adapter to fit the older style of inlet manifold.

[LLantrisant]

ok...if SNB108 would match the instrument i could use an adaptor to 5/8" unf....the 5/8UNF to 1/8NPT adapters are reasonably short, this should bring the sender definately deep enough into the manfold that it should be covered by the water.

[LLantrisant]

ford sender arrived:

this sender shows a restistance of 180 Ohm at room-temperature (which is actually 25degrees), the original sender shows 300 ohm at room temperature.

so in theory the ford sender cannot match with the gauge when already the starting point is wrong?

Edited by LLantrisant on Saturday 27th June 12:29

[LLantrisant]

yesterday i fitted the ford sender and made a test drive.

as expected (lower starting resistance, plus better location inside the water-flow), the gauge started to show a value shortly after the test-drive started.

the gauge reading was far higher than with the origianl sender,with its recessed fitting outside the water flow.

so you could think "so far , so good"

the problem is: the needle of the gauge, during driving (outside temperature 30degrees, original radiator fitted, thermostat fitted), climbed up to around 70 degrees while driving..inside town to 78, where the fans kicked-in, fan switch in swirlpot is 92degrees.

so all in all, the gauge shows at least "something"...definately more than original.....but still not correct.

[bobfather]

LLantrisant said:

so all in all, the gauge shows at least "something"...definately more than original.....but still not correct.

I often say this but here it is again, under running conditions the coolant system has a range of temperatures depending where you take the reading, hot at the cylinder walls, cooler at the radiator and values in between elsewhere. Trying to achieve perfection is a fools errand, these gauges were only ever intended to give an indication of temperature, cold, normal and hot and to indicate when the temperature is changing. Sure you can try for a reasonably accurate reading but perfection is not worth chasing. You also need to recognise that the ECU sender and the gauge sender are different technologies and this causes them to respond to temperature changes at a different rate, they can only be compared when temperature is stable and then only if they are in close physical proximity, i.e. only if you are using the Rover sender position next to the ECU sender

[QBee]

bobfather said:

LLantrisant said:

so all in all, the gauge shows at least "something"...definately more than original.....but still not correct.

I often say this but here it is again, under running conditions the coolant system has a range of temperatures depending where you take the reading, hot at the cylinder walls, cooler at the radiator and values in between elsewhere. Trying to achieve perfection is a fools errand, these gauges were only ever intended to give an indication of temperature, cold, normal and hot and to indicate when the temperature is changing. Sure you can try for a reasonably accurate reading but perfection is not worth chasing. You also need to recognise that the ECU sender and the gauge sender are different technologies and this causes them to respond to temperature changes at a different rate, they can only be compared when temperature is stable and then only if they are in close physical proximity, i.e. only if you are using the Rover sender position next to the ECU sender

This. ^^^^^^^^

Drive any modern Audi and the temperature gauge only actually has three positions to which the needle goes:

Stone cold
Running
Boiling over

Or, as I call them:

OFF
ON
STUFFED

If the gauge gives numbers, the ON position is usually around 90.

Our TVR gauges give us more information than this, but it is still all relative, and we just need to interpret what it really means.

For the later cars, the sender mentioned in this thread seems to give remarkably accurate threads, but on a hot day in traffic we just have to remember that water boils at well over 100 degrees C when the pressure is above one atmosphere, which it is in a car cooling system. It will boil at 120 or 125 degrees IIRC. So panicking because the gauge shows 95 is not necesary -so long as you can hear the fans running, and a quick check under the bonnet shows they are BOTH running, you will be fine.

[LLantrisant]

i dont want it perfect...but close would be not too bad. the sender is inside the manifold, where the water passes quite close b4 exiting into the swirlpot.....so sender location and fan-switch location are , imo, in the same water stream...

if the reading on the gauge whould be around 85-90, when the fans kick-in, this would be the goal,as with the actual readings, i would not really have an indication if the engine would be near to overheating (e.g. fan failure.).

this said i have at least an override fan switch and a control-lamp showing if the fan-relais is active or not.

[ray von]

LLantrisant said:

i dont want it perfect...but close would be not too bad. the sender is inside the manifold, where the water passes quite close b4 exiting into the swirlpot.....so sender location and fan-switch location are , imo, in the same water stream...

if the reading on the gauge whould be around 85-90, when the fans kick-in, this would be the goal,as with the actual readings, i would not really have an indication if the engine would be near to overheating (e.g. fan failure.).

this said i have at least an override fan switch and a control-lamp showing if the fan-relais is active or not.

Haven't read the whole thread but if this is what you want why not just fit the variable resistor and tweak it until the gauge reads what you want when the fans kick in? As will have been said it only makes it right at one point but that's all you are after, is it not?

[QBee]

ray von said:

Haven't read the whole thread but if this is what you want why not just fit the variable resistor and tweak it until the gauge reads what you want when the fans kick in? As will have been said it only makes it right at one point but that's all you are after, is it not?

I had that mod for a while. I adjusted it to be correct at normal warm weather running temperature, ie just below fan kick in temperatures.
My issue with it was that it then didn't tell me when the engine was getting too hot - it was good as the engine warmed up, but it never read any higher than 85 degrees.
As far as i am concerned, the only thing that matters is knowing when there is an overheating issue - the rest is just window dressing.
The new sender TT1168-03 is accurate all the way up, I have had it at over 100 degrees (water under pressure boils at 120) on a track day running a turbo. My oil temperature gauge was showing a similar temperature.

[bobfather]

If you can get the bezel off you should be able to ease the needle off the pin. You could then take the sender out, extend the signal wire, add a wire to ground the sender thread to the block and dunk the sender in a kettle. Bring it to the boil and pop the needle back on at 100degC. A fiddly job but it'll give you the result you're looking for

https://www.youtube.com/watch?v=KhLHL4bp-v8

I have one of these pointer extractors if you live anywhere near me

Pressure Gauge Pointer Lifters are also available on eBay

Edited by bobfather on Monday 29th June 13:16

[LLantrisant]

ray von said:

Haven't read the whole thread but if this is what you want why not just fit the variable resistor and tweak it until the gauge reads what you want when the fans kick in? As will have been said it only makes it right at one point but that's all you are after, is it not?

variable resistor? how? for solving my problem the final resittance must be lower. so adding a resistance in parallel would correct this, but would give totally wrong readings from cold to proper temperture and wrong readings from proper temperature to overheating

Edited by LLantrisant on Monday 29th June 20:11

[LLantrisant]

QBee said:

I had that mod for a while. I adjusted it to be correct at normal warm weather running temperature, ie just below fan kick in temperatures.
My issue with it was that it then didn't tell me when the engine was getting too hot - it was good as the engine warmed up, but it never read any higher than 85 degrees.
As far as i am concerned, the only thing that matters is knowing when there is an overheating issue - the rest is just window dressing.
The new sender TT1168-03 is accurate all the way up, I have had it at over 100 degrees (water under pressure boils at 120) on a track day running a turbo. My oil temperature gauge was showing a similar temperature.

you are talking about different brand of gauges, hence different senders, ...my gauges are from ETB!!!

[LLantrisant]

bobfather said:

If you can get the bezel off you should be able to ease the needle off the pin. You could then take the sender out, extend the signal wire, add a wire to ground the sender thread to the block and dunk the sender in a kettle. Bring it to the boil and pop the needle back on at 100degC. A fiddly job but it'll give you the result you're looking for

https://www.youtube.com/watch?v=KhLHL4bp-v8

I have one of these pointer extractors if you live anywhere near me

Pressure Gauge Pointer Lifters are also available on eBay

Edited by bobfather on Monday 29th June 13:16

too complicate...and removing the upper dash-panel again is not in my interest.. once removed, the gauge would be thrown out and a different brand with capilary sender fitted, no matter if the design matches with the rest.

[gamefreaks]

I fitted this sensor to my Chim this weekend.

Bit of a no-brainier to install this sender as replacing the original TVR sender looks like a pain due to access (or lack of!)

Really simple to fit. I just unclipped the dizzy cap and removed the ECU sensor to get access for my spanner’s.

I bought mine from Caterham Parts (Caterham part number 71167). They sell them individually for £15 + P&P.

I don’t have a RG cable so I tested with an IR thermometer. The dash gauge reading agrees very closely with temp of the top hose that runs between the swirl pot and the thermostat housing.