200tdi temp gauge woes

Hi, I’ve seen loads of posts about temp readings etc but nothing that answers my problem, I Recently purchased a 1986 110 which has had a 200tdi fitted to replace the original engine. Since having it the temperature gauge only really gets out of the cold and up to the 1st bar. I’d expect under normal driving and pushing it a bit to move to vertical at least.
Recently noticed that expansion tank was empty and that there was a leak on the bypass hose so now replaced.
Have topped up coolant and run it a little, radiator remained cold but temp sensor housing was warm to the touch. Quick blast up the road and radiator got hot. gauge still reading the same just off cold. I believe I have the original gauge but also that this gauge is the same on a 200tdi. Can anyone tell me what the likely cause of this is? Happy to order a new sender but not sure if PRC8593 is the correct one or not.
Heater is getting warm air into cab but not particularly hot in my opinion, probably hotter when on motorway and need my thermal socks during normal tooting about.
Have a viscous fan but no shroud and no electric fan.
Vehicle has no switch temp sensor on top the thermostat housing - is this only used for electric fan???

any advise gratefully received. Have read about other temp senders and gauges but links on forum posts are all out of date and don’t give any part no’s

The viscous fan needs a shroud I have been told, I have a 200 tdi in a 1984 PU 110.
The are very efficient with a shroud not so much without.

have you checked changed the thermostat?
I had a small leak sitting in storage, still waiting for time to check which hose.

Do you know what vehicle your 200tdi came out of?
I think the sensors are different for different models.
When I did a discovery 300tdi conversion into my 1988 90 I bought a new Stack guage and sensor, didn't trust the old guage I had.
I ran it without a viscous fan, just used an electric one

Seaswood said:

The viscous fan needs a shroud I have been told, I have a 200 tdi in a 1984 PU 110.
The are very efficient with a shroud not so much without.

have you checked changed the thermostat?
I had a small leak sitting in storage, still waiting for time to check which hose.

Click to expand...

Got a new thermostat but the existing one opens and closes as rad stays cold then hot once this temp is reached. Would have thought not having a shroud would cause it to get too hot if anything?

When I posted about not having a shroud a few weeks ago the consensus was that it wouldn’t need one.

steve24v said:

Do you know what vehicle your 200tdi came out of?
I think the sensors are different for different models.
When I did a discovery 300tdi conversion into my 1988 90 I bought a new Stack guage and sensor, didn't trust the old guage I had.
I ran it without a viscous fan, just used an electric one

Click to expand...

it came from a defender 200tdi. There appear to be several original senders but the same gauge for both. Have read of many people changing to duralite or vdo gauges but they have their own range of senders and adapters and that’s even more confusing.

You could have a broken guage, it was a long time ago when I did my conversion buti remember it being a nightmare trying to work out what sensor I would need. Originally mine was a petrol V8, which had a 6.5 diesel V8 in when I bought it so figured it would be better to get a new guage with a sensor to give a true reading.
As for the heater, they are 5hit. I removed mine completely, never got any hot air out of it and if I did it was barely warm. The matrix probably wanted cleaning out but all the defenders I've been in never had decent heaters.
I didn't have a radiator cowl on mine and never had any issues, guage didn't go above 90° unless I floored it going uphill

For a fan to be efficient it needs some sort of shroud otherwise it just moves air around rather than pull it through the rad.
My sons TDI heater was useless so fitted a new genuine thermostat and fitted a rad muff, heats up quickly and now actually provides some warm air. You can feel when the thermostat opens and can also feel that the rad and fan are doing their jobs. The down side to this being his sender is incompatible and therefore reads rather high and being a tdi out of a Disco it has a silly thread size.
Get a infa red temp gun as they are excellent tool for helping temp problems.
Steve Parker website has a fair bit of info on it about sensor thread size and type.

steve24v said:

You could have a broken guage, it was a long time ago when I did my conversion buti remember it being a nightmare trying to work out what sensor I would need. Originally mine was a petrol V8, which had a 6.5 diesel V8 in when I bought it so figured it would be better to get a new guage with a sensor to give a true reading.
As for the heater, they are 5hit. I removed mine completely, never got any hot air out of it and if I did it was barely warm. The matrix probably wanted cleaning out but all the defenders I've been in never had decent heaters.
I didn't have a radiator cowl on mine and never had any issues, guage didn't go above 90° unless I floored it going uphill

Click to expand...

Agree re the heater. Only really mentioned it incase that’s a symptom of the problem. My
Fuel gauge internal resistor broke down so I’ve just replaced that. Perhaps being next to it and if similar age the same has happened.

The 'sender' is a thermistor, it changes it's resistance as it get hotter.
To check the gauge simply remove the wire from the sender and touch it to the engine/ground. The needle should go to HOT..
There are a couple of different senders, these have a different resistance when cold.
The Discovery is a green sensor PRC99217 and the other is a Defender one PRC8593/PRC8001 ....

I don't know the resistive values so can't advise further but I (personaly) would go for the PRC8593.
Try touch the sensor wire to ground first and see if that max's out your meter.

Also see here ....

miktdish said:

The 'sender' is a thermistor, it changes it's resistance as it get hotter.
To check the gauge simply remove the wire from the sender and touch it to the engine/ground. The needle should go to HOT..
There are a couple of different senders, these have a different resistance when cold.
The Discovery is a green sensor PRC99217 and the other is a Defender one PRC8593/PRC8001 ....

I don't know the resistive values so can't advise further but I (personaly) would go for the PRC8593.
Try touch the sensor wire to ground first and see if that max's out your meter.

Also see here ....

Click to expand...

thanks. Sounds like a sensible idea. Prc8593 is also what I think should be fitted

Mini type capilliary gauge off ebay etc, dead accurate and always works.
Might need an adaptor for sensor end.
You will be surprised just how cold the things run.

https://www.ebay.co.uk/itm/29362653...SAf717O0FWy%2BYvmXcx|ampid:PL_CLK|clp:2047675

Plus on on the above, fit and you will know the actual temp yours runs at.

This may be water temperature, I have been trying to get oil temperature gauge to work, it worked before.
Did all the tests as Mike explained “ he is great” everything looked good except the sender.
Oil temperature sender comes off top of oil filter housing & not the oil pressure switch.
PRC4372 Temperature Transmitter Listed as optional equipment on 1986 fiche
This I was told is NLA.

does anyone use a oil temperature gauge I am using PRC 3115
When sender wire is grounded it goes all way up remove wire comes all way down.
Problem is finding the sender.

PRC4372 - Transmitter Oil Tempreture 90/110 2.5 Diesel N/A and Turbo (johncraddockltd.co.uk)

Sender Oil Temperature - PRC4372 (lrseries.com)

@Seaswood
Says available in these 2 examples.

And this 1 PRC 4372 EPS, FACET Sensor, Coolant temperature cheap ▷ AUTODOC online shop

J

hello, yes sorry this item is now obsolete,. Lrseries.com
I could not get through Craddock paywall.
appears this is discontinued by Land Rover?

Craddock got back to me since the item was still in process for purchase.
Yes this is nla everywhere else I checked, oil temperature sensor 2.5 na
i think maybe Blanchard sold either a bad unit it had low ohm’s or a 24 V sensor.
I now have a working oil temperature gauge that is I believe a Xmod only feature.
thnx
craddocks were great I can say!

This sender loosened up leaked oil 1.5 LT I retightened & I should be able to get quite tight.
but the last bit of turn I felt a slight give. Not entirely sure if the threads are a match This is a nla item?
I am tempted to coat threads in Red loctite unless someone has other ideas?
thnx