temperature guage sender

[daz the plumber]

just managed to change the sender by just removing the dizzy cap, fuuny thing its only been in a for two years .ive followed the bible to vent the system of air but the temperature guage is going over 100 degrees and the fans are not kicking in .i have by passed the otter switch to find the fans work ok .don`t know if its a coincidence that this has just stopped working or its another problem .
i half filled the bottom vessel then filled the swirl pot to the top then left both tops off ,gently adding more coolent to the bottom vessel .ive allso vented the radiator and put the heater on full .think this is the right procedure . the problem i have is the fans are not kicking in .

Edited by daz the plumber on Thursday 30th April 14:43

[rigga]

Are you sure you have not changed the fi temp sender and not the guage one? and the duff sender is still in situ?...thats if the guage sender is duff at all,normally ground the wire to see if the needle sweeps all the way round on the guage to prove thats ok,a thermal temp gun would be usefull to actually see if the engine is getting that hot,id suspect your otter switch is not working if you bridge the wires and the fans cut in,but not by themselves

[scotty_d]

The way i bleed the system Is to top the swirl pot up till it will take no more as it fills the radiator up (can take a little while) then put its cap on, half fill the expansion tank put its lid on set heater to full hot crack the radiator bleed screw and run the car up and let it flow till I get a good stream of coolant from the radiator then nip up. Think you are on the right track that side of things. I would say the otter is faulty? test it with hot water and a multi meter?

[chrispitman]

The fans are controlled by the otter switch either in rad or on swirl pot, on the inlet manifold the sensor on pass side with a two pin (Injector style) connector is the ecu temp sensor the one in the V just above the valley gasket is the Gauge temp sender with a single wire connection. I wouldn't trust what the dash gauge says as they can be way out.

[blujay10]

Does it go straight up with just the ignition on? If it does, the new sender may need a resisitor to calm it down? Walldonway found this when they recently changed mine.

[WOO5IE]

Hi Daz

Are you sure you have the correct sender to match the guage as I believe there are a couple of variants

Trev

[Tyre_Tread]

OK Guys, I'm confused! (I know it doesn't take much!)

Car passed MOT today

On the way home the temperature gauge stopped working altogether. It has been reading lower than usual for a while and I've kept an eye on it but now dead as the proverbial Dodo.

I read the Bible and it says I should expect to see a connection for the gauge just behind the main temp sensor for the ECU. The gauge sensor appears to be there but not connected to anything.

The wiring diagram in the SH book says the temp gauge sensor should have a green wire with a blue tracer. One of the wires going to the multiplug on the "ECU Sensor" is Green/blue with the other being red/black.

Can anyone confirm which/where is the gauge sensor please.

Picture in case it helps (taken from pax side) so dizzy to the left and plenum to the right.



Edited twice for spooling

Edited by Tyre_Tread on Thursday 30th April 18:08

Edited by Tyre_Tread on Thursday 30th April 21:52

[Cider Andy]

That's the Range Rover sender. Presumably TVR left it in there as a blanking plug. The TVR sender is mounted horizontally in a brass hexagonal boss/extender behind the distributor.

You can use the RR sender if you place a 120R resistor in series with it.

[SP6 Animal]

Not a good picture but you can just about see the spade connector of the switch in the centre of the picture right behind the dizzy.

[daz the plumber]

yes i put the temperature sender wire to ground causing the guage to fly up to max .the guage works well now and gets up to temp with in 5 minutes on idle .the only problem is the fans are not kicking in , may be some water which a has vented down the side of the swirl pot as damaged the otter switch .regarding the sender , both were purchased from the tvr shop so , well hope be to the right one .if the sender is a standard rover part i can purchase this item for £4.50 but i opted to spend £12 as it may be calibrated for the ford clocks , who knows !yes thats the one behind the dizzy , and yes it was a b...,,d .did not want to remove the dizzy but got there in the end .

Edited by daz the plumber on Thursday 30th April 21:23

[Tyre_Tread]

OK I see it now


I'd love to use the RR sender but am hopeless beyond basic electronics and don't have a 120R resistor (Should that be 120ohm?)

[debaron]

Cider Andy said:

That's the Range Rover sender. Presumably TVR left it in there as a blanking plug. The TVR sender is mounted horizontally in a brass hexagonal boss/extender behind the distributor.

You can use the RR sender if you place a 120R resistor in series with it.

You can but this only gives a correct reading at one particular temperature and should be avoided. ie the gauge will be out of calibration except at one intersection of the 2 temp curves.

The gauge temp sender is behind the dizzy - Pic below. Trace the green wire down and you can just see the brass fitting just above the blue plastic of the dizzy.

[debaron]

Daz, I'm only guessing here but with the ignition on and engine off, if you pull the two terminals off the otter switch (bottom of the swirl pot) and touch together. That should fire the fans. Then you'll know if it's a switch or lead problem.

[Tyre_Tread]

Didn't mean to hijack the thread - sorry Daz.

Thanks everyone, I have now located the sender and earting the wire sends the gauge right up so it looks like I'll be remving the same amount of skin as Daz.

Any tips on this Daz? How much water did you lose taking the sender out?

[daz the plumber]

if you dont want to remove the whole dizzy i managed to swop mine by removing the large top hose ,removing the dizzy cap .that is the simple bit ,i then removed the sender with a standard open end spanner .the next step was to guide the sender in to position a then add pressure with a screw driver while using the spanner .i put the cable on first then re connected with a bullet connector .is this sender a standard rover part for future refernce and to save some money . !

Edited by daz the plumber on Thursday 30th April 22:11

[locodude]

I believe that it is calibrated specially for the TVR gauges (2 types I believe)

[Tyre_Tread]

locodude said:

I believe that it is calibrated specially for the TVR gauges (2 types I believe)

OK so I gather that it depends upon the type of guages you have fitted.

I have the later white gauges (2000 car). I can only find one listed at the TVR shop. When I click on the add to basket sign next to the sender it goes to my basket and says it is empty.

How difficult does it have to be to order a bleedin' water temperature sensor?

[Tyre_Tread]

Called local TVR speacilist PPC in Melton Mowbray - wife's idea! Why didn't I think of that? but they didn't have any in stock stupid mare .

I had already looked at Clever Trevor website. They want £8.00+ as minimum posteage - Cheeky buggers.

PPC suggestted I call Peninisular. They are a bit dearer at £14.00 but postage only £1.20. Still a lot for a temp sender though!

I have a spare sender for my other Rover V8 so when the new one arrives I'll experiment with the new TVR one and the spare non TVR one along with a cup of water and thermometer while connecting up to the guage and see how much, if any, difference there is.

;sitsondoorstepwaitingfopostman:

[daz the plumber]

still know luck , fitted a new otter switch today, the fans are not kicking in even when the guage is reading 100 , when i stick the wire across the terminals the fans kick in .this problem emerged from loosing the coolent when fitting the temp sender .i can not feel any water in the top hose , the bottom vessel starts half full then fills to the top which is what i don`t want .

Edited by daz the plumber on Friday 1st May 21:53

[SP6 Animal]

Daz when you bled the system did you have a good flow of water coming out of the drain plug on the top of the rad.
Top hose cold not good as you know.
Did i read you used PTFE tape on the sender that may have blocked the hole restricting the water flow.
Just a thought.