Engine coolant temperature sensor

Sorry guys i lost this post for some reason, just getting used to how all this works. The Rangy is new to me so i am working out all its faults. it is the 2.5 DSE

I changed the thermostat tonight and found there was nothing inside. So replaced it, but still not got anything on the guauge. I guess i need to change the sender unit next. I have located it but not taken it out, but it looks brand new. Do i bit the bullet and change it too? or could it be something else.

I put my infra red heat gun on the top pipes and got 80 degrees tonight, just with it running in the garage.

Before i took it all apart i was out in it and dropped a gear and there was a puff of smoke out the back, not sure what colour, then i was not able to go above 60.

There was a box of injectors on the back seat when i bought it. Look in good nic with a receipt saying they have been reconditioned.

thoughts?

gcracingteam said:

Sorry guys i lost this post for some reason, just getting used to how all this works. The Rangy is new to me so i am working out all its faults. it is the 2.5 DSE

I changed the thermostat tonight and found there was nothing inside. So replaced it, but still not got anything on the guauge. I guess i need to change the sender unit next. I have located it but not taken it out, but it looks brand new. Do i bit the bullet and change it too? or could it be something else.

I put my infra red heat gun on the top pipes and got 80 degrees tonight, just with it running in the garage.

Before i took it all apart i was out in it and dropped a gear and there was a puff of smoke out the back, not sure what colour, then i was not able to go above 60.

There was a box of injectors on the back seat when i bought it. Look in good nic with a receipt saying they have been reconditioned.

thoughts?

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Be aware there are two temp sensors on the left side of the engine below the manifold. The front one is the ECU temp sensor the one you want is the rearward of the two, the dash gauge temp sensor.

prob should have explained a little better didnt mean failed open after the issues i had with a britpart stat that cooked the engine i bought a genuine landrover one fitted but it allways ran cold ie above the blue on the guage so removed and tested properly by heating cold water in a pan with a thermometer in it found it was opening to early.
actually ended up fitting the thermostat out of my scrap pile that one came out an engine i bought and had sat there for months in a pile of bits outside that i took off and worked a treat.
i hate it when people say they have tested it in boiling water, which proves nothing except it opens or it doesnt in boiling water. stats can open at the wrong temp, to early cool running or to late over heating temps are stamped there and they should be tested properly.
seen a dse with a stat that opened about 10 degrees below where it should it would run at idle and operate perfectly but on the road the airflow over it would cool it enough to shut and then it would overheat on hills and one half of the rad would be cold and the other would be hot.
tis the only reason why i say stats should be checked properly they can throw up strange cooling issues when operating incorrectly.
but i totally agree that any dse running with the temp down near the blue has a duff or missing stat

sorry to dig up a old thread but would rather add to this one rather than create a new one. I have a 2.5 dse auto 1997 p38 and i'm having similar issue with the car never getting hot enough for the needle to leave the blue zone on gauge. I have three questions really:

1.Would you go for a genuine stat or after market one?
2.did you replace the o ring on both the stat and the smaller coolant pipe that you have to remove (as the rave cd says you do)
3.which antifreeze do i need as rave says use ethynol glycol based but halfords anti freeze just says pre or post 1998 and something about OAT?

thanks in advanced for your help

Yes always go with a decent make....cheap stats can fail closed!!

Always replace sealing washers and gaskets - sound practise...but you take your chance if you don't...wouldn't be prudent to say no leave them, then you end up with a leak and a knackered head due to overheat....

If you current is BLUE/GREEN replace with same...if it is RED go with that, you can't mix Anti-Freeze mixtures, the two types Organinc and Non-Organic, have different inhibitors in, and one cancels the other out and makes them useless....

Appreently my L322 should be RED, but I have BLUE in mine...so stick with it - no issues...!!

Saint.V8 said:

Yes always go with a decent make....cheap stats can fail closed!!

Always replace sealing washers and gaskets - sound practise...but you take your chance if you don't...wouldn't be prudent to say no leave them, then you end up with a leak and a knackered head due to overheat....

If you current is BLUE/GREEN replace with same...if it is RED go with that, you can't mix Anti-Freeze mixtures, the two types Organinc and Non-Organic, have different inhibitors in, and one cancels the other out and makes them useless....

Appreently my L322 should be RED, but I have BLUE in mine...so stick with it - no issues...!!

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thanks for the reply. I was leaning towards genuine and new seals but makes me happy to know that the extra money is worth it. the coolant looks an orange colour, looks reasonably new so will try find the same stuff.

Hopefully be able to get a little more mpg because at the mo if i drive at 50 on a flat road like an angel i get 25 mpg, thats with 40 psi in both front and rear tyres and the brakes are running freely so ive put it down to engine running rich due to stat. fingers crossed

landykyle said:

thanks for the reply. I was leaning towards genuine and new seals but makes me happy to know that the extra money is worth it. the coolant looks an orange colour, looks reasonably new so will try find the same stuff.

Hopefully be able to get a little more mpg because at the mo if i drive at 50 on a flat road like an angel i get 25 mpg, thats with 40 psi in both front and rear tyres and the brakes are running freely so ive put it down to engine running rich due to stat. fingers crossed

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Yeah, I'd expect closer to 28-31 on a steady pace...I averaged 25.6mpg from my DSE and that was over a 6 month period and covered motorways, towns and coutry lanes!

Saint.V8 said:

Yeah, I'd expect closer to 28-31 on a steady pace...I averaged 25.6mpg from my DSE and that was over a 6 month period and covered motorways, towns and coutry lanes!

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Would be more than happy with those figures. Stat tomorrow and then a three hundred mile trip at the weekend so will report back my findings.
thanks again

landykyle said:

sorry to dig up a old thread but would rather add to this one rather than create a new one. I have a 2.5 dse auto 1997 p38 and i'm having similar issue with the car never getting hot enough for the needle to leave the blue zone on gauge. I have three questions really:

1.Would you go for a genuine stat or after market one?
2.did you replace the o ring on both the stat and the smaller coolant pipe that you have to remove (as the rave cd says you do)
3.which antifreeze do i need as rave says use ethynol glycol based but halfords anti freeze just says pre or post 1998 and something about OAT?

thanks in advanced for your help

Click to expand...

Whilst agreeing with the other answers I'd just add that it would be a good idea to check your fan whilst you're at it.

dogsbody said:

Whilst agreeing with the other answers I'd just add that it would be a good idea to check your fan whilst you're at it.

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yeah, read about that. whilst i have not physically checked it, i have heard it run when cold and then goes quiet after a while so guess it would be ok. I suppose the old news paper test wouldn't go a miss?

landykyle said:

yeah, read about that. whilst i have not physically checked it, i have heard it run when cold and then goes quiet after a while so guess it would be ok. I suppose the old news paper test wouldn't go a miss?

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Yea. Not exactly a precise science but if it shreds the paper at all times it might account for, at least, part of your problem.

Right, some great news, a new stat and she's gone from 26 mpg driving very carefully to 28.5 driving not as carefully and the gauge is bang on the middle!

landykyle said:

Right, some great news, a new stat and she's gone from 26 mpg driving very carefully to 28.5 driving not as carefully and the gauge is bang on the middle!

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Happy Days!!

landykyle said:

Right, some great news, a new stat and she's gone from 26 mpg driving very carefully to 28.5 driving not as carefully and the gauge is bang on the middle!

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Good result and thanks for posting it.

Datatek said:

Good result and thanks for posting it.

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Prepare for all outlets to be low on stats and temp sensors some time soon.

Digging up this old post again as my temperature gauge doesn't seam quite right.

2001 P38 V8

Fan & Thermostat works 100% fine, checked and re-checked and again to be sure.

Gauge doesn't go much above blue, see the photo.

I have changed sensor MEK 100160 to no avail.

Only have obd2 reader but i can see the temperature raising up to mid 80's

Really baffling, thinking Earth or Gauge fault, any suggestions welcome

I have high change issues with my auto diesel and have read on the forum in range rovers .net that a faulty temp sensor can cause this.
I am in Mongolia and trying to source the engine ones and also the fuel temp sensor in the FIP but cant find the part number for any of them so would appreciate if any one could supply them and also a supplier on the net that will send them here.

ovalandrover said:

I have high change issues with my auto diesel and have read on the forum in range rovers .net that a faulty temp sensor can cause this.
I am in Mongolia and trying to source the engine ones and also the fuel temp sensor in the FIP but cant find the part number for any of them so would appreciate if any one could supply them and also a supplier on the net that will send them here.

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Range Rover P38 94-02 - Island 4x4 - Specialists in Land Rover and Range Rover Parts and accessories for all models. UK and worldwide mail order.

Do you have any form of diagnostic with you?

ovalandrover said:

I have high change issues with my auto diesel and have read on the forum in range rovers .net that a faulty temp sensor can cause this.
I am in Mongolia and trying to source the engine ones and also the fuel temp sensor in the FIP but cant find the part number for any of them so would appreciate if any one could supply them and also a supplier on the net that will send them here.

Click to expand...

Look in my "How to" for a link to fuel temp sensor. Don't know if he still has stock but worth a try. I don't see how fuel temp sensor would cause gearbox problems.

Druim said:

Digging up this old post again as my temperature gauge doesn't seam quite right.

2001 P38 V8

Fan & Thermostat works 100% fine, checked and re-checked and again to be sure.

Gauge doesn't go much above blue, see the photo.

I have changed sensor MEK 100160 to no avail.

Only have obd2 reader but i can see the temperature raising up to mid 80's

Really baffling, thinking Earth or Gauge fault, any suggestions welcome

Click to expand...

The temperature reading goes via an analogue to digital convertor in the BECM then via another digital to analogue convertor to the gauge. I'm not aware of any standard OBD reader that can read BECM data.
If diagnostics show the temperature rising at the BECM, then the fault is either bad connections on the output to the gauge, a bad earth or the gauge itself. Diagnostics can be used to drive the gauge to test it.