What Temp sensor/sender is right for 2.5 Petrol 17H?

Hi All,
So I thought I'd put this in the series section as there isn't a dedicated subforum and I know some people do swap the 2.5 17H petrol engine into series Landys.
Backstory is that in my newly acquired 110 the temp gauge is getting quite high and almost into the red when the engine is up to temp, I've not been on any long drives yet, just a mile runs so far due to other issues like the brakes that im working on getting sorted out. I was told by the seller it's the temp sensor at fault, it doesn't actually overheat, and that does seem to be the case so far... nothing seems like its getting too hot checking with an infrared thermometer. I'll probably replace the thermostat anyway as I guess that could also be the issue, but I was trying to search for the right temp sensor for the 17H engines.

I bought PRC3541 as it was listed as being right but firstly its got 2 pins instead of just one, and also its massive! Now I see there is an adapter between the current sensor and the block but it still just seems a bit big? Also if it did happen to fit what about the second pin? is that just a ground? So what do you guys think? what actually is supposed to be the right one for the 17H? also any other thoughts on this issue?

Current sensor:

From what I know.
If the PO is saying its the sender and its not getting hot (you have checked physically) then he is probably right.

What engine was in the 110 originally as thats the sender you need to match the gauge, assuming the gauge is original. and yes you may need an adaptor of some sort.
So you will have to do a bit of digging/searching. It has been mentioned/discussed on here many times.
You may find you have the correct sensor (evidence of possible adaptor) so maybe it is just broke .

You may also find somebody has left out the thermostat, because of the assumption it was getting hot. Test the new thermostat works before putting it in.

J

marjon said:

From what I know.
If the PO is saying its the sender and its not getting hot (you have checked physically) then he is probably right.

What engine was in the 110 originally as thats the sender you need to match the gauge, assuming the gauge is original. and yes you may need an adaptor of some sort.
So you will have to do a bit of digging/searching. It has been mentioned/discussed on here many times.
You may find you have the correct sensor (evidence of possible adaptor) so maybe it is just broke .

You may also find somebody has left out the thermostat, because of the assumption it was getting hot. Test the new thermostat works before putting it in.

J

Click to expand...

It is an original 17H, not been swapped, although it does raise the question has the gauge been swapped at some point? I was reading that the gauges and sender need to be matched and was hoping this would just be some sort of mismatch between the two.

On doing some more googling it seems that the PRC3541 is wrong, and it should either be a PRC2505 or PRC6663 for a 17H depending on VIN... with a couple of sites suggesting I need the former! So I've ordered one of those. I guess I could also pull out the old sender and test it in some 80-90C water while still grounded to the block? If that reads high then its definitely an issue with the sender/gauge. That will have to wait though as I don't want to take it out until I have all the bits to do this and the thermostat together.

Also coincidentally the Landy did come with a box of bits with a used thermostat in the back...

If thats the original engine then yes it narrows it down to being a sensor/gauge/wiring issue. So should be fairly easy to track down.
Do you have wiring diagrams for it? if not do a search it will comin handy.

So old thermostat in a box of bits . Sounds like the chances are you may not have 1 in at the moment. Test it if its good I would say highly possible you dont have 1 if you are not getting up to proper temp with your infered thermometer.

Let us know how you get on.

J

So I haven't got all my new bits yet (I foolishly thought I could order from John Craddock and actually get things within a week), I did get the new PRC2505 sender though. I thought I'd test it out so connected it up and stuck it in a cup of near boiling water, which was about 91C when I left my kitchen, probably somewhere 80-85 outside.

Unfortunately the gauge rose right up far into the red, so there is definitely still an issue somewhere. So at least this supports the idea that it's not overheating! I then pulled the gauges out and found the temp gauge is a PRC3106. Not sure if this is right or not? one site I looked on suggests this is for a later model, but others suggest it is right. I saw a PDF chart somewhere that suggests a PRC2505 sender and PRC3106 gauge should work fine so im not sure.... possible faulty gauge?

Update for anyone interested:
So I worked out with some testing with a new temp sender (PRC2505) and taking the gauge out to test separately that there was an earthing issue with the gauge. Connected up on my bench to a power supply and the new sensor, put in hot (75-85C) water the gauge was reading just under halfway, exactly as you'd expect. So that all seemed fine. I put the gauge back in with a new earth wire to the bulkhead, and after about 10 mins running the needle barely left the coldest line. The resistance between the new and old senders was similar, roughly so I assumed the old one was actually ok, and maybe as suggested here the thermostat had been removed. I cracked that open on friday night and bingo, no thermostat!

So that evening was spent cleaning up the housing and installing a new one, after testing that. On running it up to temp for 10 mins the needle was getting towards half way, good signs! On saturday I really decided to push my luck and take the 110 out for her first decent drive in 25 years... the needle only just touched the half way point and sat there quite nicely so I think thats all sorted! And a good run and getting up to temp finally seems to have blew out some cobwebs as it was idling much nicer after getting home.

Good news, thanks for coming back to tell us so many peeps dont.
Happy motoring , now onto the next problem

J

The next problem... oh yes, absolutely! I will have owned this 3 weeks tomorrow, and I've already done the rear brakes, every oil possible and thermostat. Still to make the drivers door lock and figure out if its actually burning oil or not, she was putting out a little bit of blue smoke on sunday. It's on the road now though so all moving in the right direction

scott3933 said:

The next problem... oh yes, absolutely! I will have owned this 3 weeks tomorrow, and I've already done the rear brakes, every oil possible and thermostat. Still to make the drivers door lock and figure out if its actually burning oil or not, she was putting out a little bit of blue smoke on sunday. It's on the road now though so all moving in the right direction

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When you park it up after a long drive see how much oil is on the floor.the next day Most of these leak more oil than they burn.

Hicap phill said:

When you park it up after a long drive see how much oil is on the floor.the next day Most of these leak more oil than they burn.

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I usually know if the cats been under the landy (cleaning the underneath) .

Oh and a gravel drive is the best choice

J

marjon said:

I usually know if the cats been under the landy (cleaning the underneath) .

Oh and a gravel drive is the best choice

J

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Parents decided yellow Cotswold chipping not a good choice for a drive & my landrover

Hicap phill said:

When you park it up after a long drive see how much oil is on the floor.the next day Most of these leak more oil than they burn.

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Honestly I don't think this one leaks at all! I know its practically unheard of with any Land Rover, never mind one that's almost 40!

There could be a small leak somewhere I haven't spotted yet, but I got way more on the ground trying to drain and refill everything. It's parked on gravel I don't care about so I wasn't being particularly careful.