Range Rover Temp Sender Thread Size?
Discussion
Yes. PM me your details.
BTW fitted mine (took a while for Caerbont to get it to me, but no matter) in 5 minutes without draining down at all. Only lost about a thimbleful of coolant, flow was quite slow so I wondered if there is a slight blockage? I did put finger in the hole (!) to keep loss to a minimum.
Only driven it once since and didn't have Rovergauge connected, but the temp gauge got nicely up to 92 degrees max. as the fans switched in, then cooled below 90. Never seen the gauge above 80 before. Definite improvement, it looks really credible.
BTW fitted mine (took a while for Caerbont to get it to me, but no matter) in 5 minutes without draining down at all. Only lost about a thimbleful of coolant, flow was quite slow so I wondered if there is a slight blockage? I did put finger in the hole (!) to keep loss to a minimum.
Only driven it once since and didn't have Rovergauge connected, but the temp gauge got nicely up to 92 degrees max. as the fans switched in, then cooled below 90. Never seen the gauge above 80 before. Definite improvement, it looks really credible.
Had a good run out today in warm weather with mixed driving including traffic jams and brisk running. Gauge read as it should under all conditions. I checked it several times with Rovergauge and during the initial warm-up from cold, up til 70 degrees or so indicated, the gauge read about 5 degrees higher than Rovergauge. Once past 70, the difference reduced to 2 degrees and for all the important temperatures (80 - 92 degrees) the gauge was within 2 degrees of the RG readings, to the best of my judgment.
Very pleased with this mod, it is great to be able to trust the gauge; it was clearly not credible previously. Thanks COG for finding this one and passing it on.
Very pleased with this mod, it is great to be able to trust the gauge; it was clearly not credible previously. Thanks COG for finding this one and passing it on.
Austin Seven said:
Very pleased with this mod, it is great to be able to trust the gauge; it was clearly not credible previously. Thanks COG for finding this one and passing it on.
Great news, gad it helped 
I fully expect the TVR parts specialists get hold of this one, which I think will be a good thing for the TVR community as they will buy in bulk and sell in singles.
Fitted mine yesterday and all seems good. Gauge reading 92 as fans come on/off and readings stable.
Haven't tried it on a long run but can’t see any reason why readings would change.
I’ve had yo-yo water temp readings based on road speed for years, heat soak when in traffic and gauge slowly creeping north although temps via Mbe Ecu sender have always been stable .
Credit where credits due,
I often say this but MOD of the year by the looks of this.
Excellent research and results so far.
Thanks for taking the time to share this useful info COG.
Haven't tried it on a long run but can’t see any reason why readings would change.
I’ve had yo-yo water temp readings based on road speed for years, heat soak when in traffic and gauge slowly creeping north although temps via Mbe Ecu sender have always been stable .
Credit where credits due,
I often say this but MOD of the year by the looks of this.
Excellent research and results so far.
Thanks for taking the time to share this useful info COG.
A very interesting thread that has provided me with lots of really clear information so thank you first of all. I am experiencing the very problems detailed with my new Chim not getting to temperate when driving at motorway speeds. This to me sounds like the thermostat is most likely sticking open.
I have now ordered the replacement sender from Caerbont to resolve the inaccuracy in what the gauge is reading.
With regard to the recommended 88 degree thermostat what have you guys been fitting? The usual TVR parts suppliers only look to have 82 degree ( big bore 31mm) and 74 degrees.
Would anyone be kind enough to point me in the right direction please.
I can find 88 degree thermostats from various Land Rover suppliers but am unsure if there is a TVR spec 88 degree thermostat available that has the 31mm bore or am I looking into this to far and any 88 degree one will be just fine.
Many thanks Andy
PS - I am new here so please be gentle !!
I have now ordered the replacement sender from Caerbont to resolve the inaccuracy in what the gauge is reading.
With regard to the recommended 88 degree thermostat what have you guys been fitting? The usual TVR parts suppliers only look to have 82 degree ( big bore 31mm) and 74 degrees.
Would anyone be kind enough to point me in the right direction please.
I can find 88 degree thermostats from various Land Rover suppliers but am unsure if there is a TVR spec 88 degree thermostat available that has the 31mm bore or am I looking into this to far and any 88 degree one will be just fine.
Many thanks Andy
PS - I am new here so please be gentle !!
Edited by Winged_Avenger on Wednesday 7th August 17:26
An 88 degree thermostat works just fine, warm up is fast and it holds 85 - 88c on a run, it's also the thermostat value the engine is intended to run.
A lot of people fit an 82c thermostat (TVR included) but that doesn't make it right any more than the too cold no 7 endurance plugs TVR fitted were right, TVR seemed to be setting the engine up for the track but the truth is most drive exclusively on the road so no 6 plugs and an 88c thermostat are a far more suitable choice.
An 82c thermostat is probably preferably if you're a track day kind of guy, but you will hold around 80c on a run and often lower in winter so you'll suffer poor heater performance, but more importantly the engine management system expects a higher figure of 85 to 88c on a run.
Never fit a thermostat in the 70s as these will give very poor heater performance in the winter when you need it and the engine management system will not leave warm up enrichment, this will shorten spark plug life, kill your fuel economy and probably your kill lambda sensors too.
Enjoy, Dave.
A lot of people fit an 82c thermostat (TVR included) but that doesn't make it right any more than the too cold no 7 endurance plugs TVR fitted were right, TVR seemed to be setting the engine up for the track but the truth is most drive exclusively on the road so no 6 plugs and an 88c thermostat are a far more suitable choice.
An 82c thermostat is probably preferably if you're a track day kind of guy, but you will hold around 80c on a run and often lower in winter so you'll suffer poor heater performance, but more importantly the engine management system expects a higher figure of 85 to 88c on a run.
Never fit a thermostat in the 70s as these will give very poor heater performance in the winter when you need it and the engine management system will not leave warm up enrichment, this will shorten spark plug life, kill your fuel economy and probably your kill lambda sensors too.
Enjoy, Dave.
Just to add to Dave’s comments, the whole point of a thermostat is to get the engine quickly up to proper operating temperature, which is around 90 degrees C. Look at the temp gauge in your daily driver. If it even has numbers, the needle will be around 90.
One issue with our cars in winter is that the cooling system is so good that the heater never gets warm.
The other issue is that the heater matrix is in the wing and gets so s
tted up with rubbish that the heater cannot operate at all. My heater never worked properly from day one of my ownership. When my heater fan gave up I asked Mat Smith to change it for a new one. In the process of the change,(it too lives in the passenger side wing) he took the matrix out and photographed it. It was completely clogged. He cleaned it up and my heater is now toasty in all conditions of frost and snow.
One issue with our cars in winter is that the cooling system is so good that the heater never gets warm.
The other issue is that the heater matrix is in the wing and gets so s
tted up with rubbish that the heater cannot operate at all. My heater never worked properly from day one of my ownership. When my heater fan gave up I asked Mat Smith to change it for a new one. In the process of the change,(it too lives in the passenger side wing) he took the matrix out and photographed it. It was completely clogged. He cleaned it up and my heater is now toasty in all conditions of frost and snow.Winged_Avenger said:
A very interesting thread that has provided me with lots of really clear information so thank you first of all. I am experiencing the very problems detailed with my new Chim not getting to temperate when driving at motorway speeds. This to me sounds like the thermostat is most likely sticking open.
I have now ordered the replacement sender from Caerbont to resolve the inaccuracy in what the gauge is reading.
With regard to the recommended 88 degree thermostat what have you guys been fitting? The usual TVR parts suppliers only look to have 82 degree ( big bore 31mm) and 74 degrees.
Would anyone be kind enough to point me in the right direction please.
I can find 88 degree thermostats from various Land Rover suppliers but am unsure if there is a TVR spec 88 degree thermostat available that has the 31mm bore or am I looking into this to far and any 88 degree one will be just fine.
Many thanks Andy
PS - I am new here so please be gentle !!
Personally I have never had any issues of over cooling with and 82C thermostat in any weather conditions. In fact in cold conditions the cabin gets hotter faster than my other TVR's. I have now ordered the replacement sender from Caerbont to resolve the inaccuracy in what the gauge is reading.
With regard to the recommended 88 degree thermostat what have you guys been fitting? The usual TVR parts suppliers only look to have 82 degree ( big bore 31mm) and 74 degrees.
Would anyone be kind enough to point me in the right direction please.
I can find 88 degree thermostats from various Land Rover suppliers but am unsure if there is a TVR spec 88 degree thermostat available that has the 31mm bore or am I looking into this to far and any 88 degree one will be just fine.
Many thanks Andy
PS - I am new here so please be gentle !!
I suspect the vast majority of owners are running with an 82C thermostat as that is what TVR fitted, no doubt for good reason. If you want to know more, I'd suggest a call to Dom a Powers Performance who has probably dealt with and built more TVR V8 engines than anyone else.
I hate to burst your bubble, but TVR Power who were responsible for prepping the engines they bought in from Land Rover didn't always get it right, indeed its truly laughable to think TVR knew better than the highly qualified, experienced, and well funded engineers who designed the Lucas 14CUX and developed the Rover V8 engine.
This post alone proves that TVR didn't always make the right choices or do things properly, if they had done the job properly they would have fitted a properly matched sender in a proper waterway and we wouldn't need the improved sender I've presented here and so many of us have seen great improvements from.
The truth is if you fit an 82c thermostat you may well see what you think is the right temperatures on the guage, but as proved by so many its almost certainly not your true coolant temp because temp sender accuracy is apalling due to the craaapy way TVR fitted the sender in an adapter which creates a blind spur.
Im sorry to say this is just another example of the quality of TVRs engineering standards what they did with the sender was a lazy bodge so I wouldnt blindly follow what thermostat value they specified if I were you.
The sender positioning TVR got it wrong is much like their use of inappropriately too cool and shrouded number 7 heat range spark plugs, TVR were clearly taking the lessons they learned on the track and started applying them to their road cars. This is of course a flawed approach as what works well on a race car most certainly does not work well on a road car.
If you run an 82c thermostat and the shrouded numbe 7 plugs get ready for this which is a textbook example of a spark plug failing to self clean because it's not reaching a high enough temperature to self clean.
You could follow little old TVR who built cars in a shed in Blackpool, but you'll be ignoring what the very clever engine and ECU designers/engineers at Lucas & Land Rover intended, seriously just because some blokes who worked for TVR said its right doesn't instantly mean they new better than the highly qualified engineers from Lucas and Land Rover.
History teaches us quite often the complete opposite is true in fact!
This post alone proves that TVR didn't always make the right choices or do things properly, if they had done the job properly they would have fitted a properly matched sender in a proper waterway and we wouldn't need the improved sender I've presented here and so many of us have seen great improvements from.
The truth is if you fit an 82c thermostat you may well see what you think is the right temperatures on the guage, but as proved by so many its almost certainly not your true coolant temp because temp sender accuracy is apalling due to the craaapy way TVR fitted the sender in an adapter which creates a blind spur.
Im sorry to say this is just another example of the quality of TVRs engineering standards what they did with the sender was a lazy bodge so I wouldnt blindly follow what thermostat value they specified if I were you.
The sender positioning TVR got it wrong is much like their use of inappropriately too cool and shrouded number 7 heat range spark plugs, TVR were clearly taking the lessons they learned on the track and started applying them to their road cars. This is of course a flawed approach as what works well on a race car most certainly does not work well on a road car.
If you run an 82c thermostat and the shrouded numbe 7 plugs get ready for this which is a textbook example of a spark plug failing to self clean because it's not reaching a high enough temperature to self clean.
You could follow little old TVR who built cars in a shed in Blackpool, but you'll be ignoring what the very clever engine and ECU designers/engineers at Lucas & Land Rover intended, seriously just because some blokes who worked for TVR said its right doesn't instantly mean they new better than the highly qualified engineers from Lucas and Land Rover.
History teaches us quite often the complete opposite is true in fact!
Englishman said:
Winged_Avenger said:
A very interesting thread that has provided me with lots of really clear information so thank you first of all. I am experiencing the very problems detailed with my new Chim not getting to temperate when driving at motorway speeds. This to me sounds like the thermostat is most likely sticking open.
I have now ordered the replacement sender from Caerbont to resolve the inaccuracy in what the gauge is reading.
With regard to the recommended 88 degree thermostat what have you guys been fitting? The usual TVR parts suppliers only look to have 82 degree ( big bore 31mm) and 74 degrees.
Would anyone be kind enough to point me in the right direction please.
I can find 88 degree thermostats from various Land Rover suppliers but am unsure if there is a TVR spec 88 degree thermostat available that has the 31mm bore or am I looking into this to far and any 88 degree one will be just fine.
Many thanks Andy
PS - I am new here so please be gentle !!
Personally I have never had any issues of over cooling with and 82C thermostat in any weather conditions. In fact in cold conditions the cabin gets hotter faster than my other TVR's. I have now ordered the replacement sender from Caerbont to resolve the inaccuracy in what the gauge is reading.
With regard to the recommended 88 degree thermostat what have you guys been fitting? The usual TVR parts suppliers only look to have 82 degree ( big bore 31mm) and 74 degrees.
Would anyone be kind enough to point me in the right direction please.
I can find 88 degree thermostats from various Land Rover suppliers but am unsure if there is a TVR spec 88 degree thermostat available that has the 31mm bore or am I looking into this to far and any 88 degree one will be just fine.
Many thanks Andy
PS - I am new here so please be gentle !!
I suspect the vast majority of owners are running with an 82C thermostat as that is what TVR fitted, no doubt for good reason. If you want to know more, I'd suggest a call to Dom a Powers Performance who has probably dealt with and built more TVR V8 engines than anyone else.
And you wont Hoofa 
I wouldn't dream of running a lairy N/A or boosted RV8 build on a 88 stat , running hotter it is only for emission purposes nothing more 
anything I've ever built runs in the low 80's make more HP and help swerve knock running lower temps too 
TVR knew what they was doing lowering the stat opening in the crowded and cramped engine bay with the intended abuse these cars might see
I wouldn't dream of running a lairy N/A or boosted RV8 build on a 88 stat , running hotter it is only for emission purposes nothing more anything I've ever built runs in the low 80's make more HP and help swerve knock running lower temps too TVR knew what they was doing lowering the stat opening in the crowded and cramped engine bay with the intended abuse these cars might see 
At the risk of bursting a few more bubbles for the vast majority of us what we have is just a good old low compression Range Rover engine that may or may not have had a little bit of head porting work from TVR..... but mostly not!
If you put this engine in a light sports car it may well get down the road very well indeed, but not because your old Range Rover engine has suddenly and miraculously become a highly strung, high compression, high performance exotic power plant, its still an old Range Rover engine it's just moving around a lot less mass.
TVR definitely didn't know what they were doing when they fitted the temp sender in a blind spur or we wouldn't have needed this post, and they also didn't choose well when they selected NGK B7ECS spark plugs or it wouldn't be that so many have reported benefits by switching to a BPR6ES, the exact same spark pugs specified for the old Range Rover our old Rover V8 engine was directly lifted from by the way.
For the avoidance of any doubt I'm not talking about cammed up higher compression RV8 engine builds, supercharged or turbocharged engines, I'm talking to by far the vast majority who read these pages who I recommend fit an 88c thermostat. The vast majority who just like me use a good old TVR Chimaera on the road not the race track, a road car that carries what is essentially the same good old Rover V8 that in absolutely in every important respect is exactly what you got in a good old Range Rover.
Now, if you study the engine management system the vast majority of us run which of course is the exact same engine management system used on and designed for the the good old Range Rover engine you'll discover the very clever engineers who designed it intended the engine to run within a 85-95c window, of course it's up to every owner to choose if they ignore this.
The good old Range Rover and its good old Rover V8 as fitted to the average good old TVR Chimaera used on the road which fits the profile of the vast majority of us is an engine that was designed to run BPR6ES spark plugs an an 88c thermostat, indeed the value of the thermostat is one of the critical components that not only makes up the cooling system its and equally critical component in the Lucas14CUX fuel injection system.
Of course despite the fact the highly qualified engineers at Land Rover would have conducted extensive reliability testing of the good old Rover V8 engine with an 88c thermostat in engine testing facilities that would have made the whole TVR company look like a shed at the bottom of your garden I would still never recommend an 88c thermostat to my TVR friends unless I myself had completed my own testing and seen clear benefits with absolutely no risks or downsides.
So for anyone still questioning what Land Rover specified for the good old Rover V8 and if its the right choice for your good old Chimaera that runs the same good old low compression Rover V8, I'm here to tell you I've run the 88c thermostat for some six years now and over tens of thousands of miles.
For the record my TVR does not live under a cover in the back of the workshop 90% of the year doing next to no miles every year, my TVR gets used almost every day of the week in all road conditions and all weathers. Time and time again my good old Rover V8 engine with its 88c thermostat has seen ambient temperatures soar to over 100 degrees Fahrenheit while stop start creeping along in horrific traffic jams in the South of France and Itally.
Also keep in mind my 88c thermostat equipped TVR runs on hot burning LPG that has none of the cooling effects of petrol, so if you're still not sure the engineers at Land Rover knew what they were doing when they specified an 88c thermostat for the good old Rover V8 as fitted to the vast majority of good old road driven Chimaeras don't worry, I've done six years and tens of thousand of miles of additional exhaustive and intensive stress testing of my engine fitted with an 88c thermostat and I'm hear to 100% reassure you all there are absolutely no risks whatsoever.
Now if we focus on the dreaded overheating condition for a moment of course it doesn't matter a jot if you fit a 75c, 82c or an 88c thermostat, because the fact is your peak temperature when you actually run the risk of overheating is still going to be the exact same 95c because all these example thermostat values will be fully open well below 90c, so all of them will be doing absolutely nothing to assist engine cooling at idle to save you from overheating.
Remember engines don't tend to to overheat when you're just driving about, air flow through your radiator sees to that, liquid cooled engines tend to overheat at idle which is why we tend to see this happen in traffic jams. To be clear if you fit an 82c thermostat you'll be driving about at 80-82c so the only difference when driving about on an 88c thermostat is you'll see 85-88c and both will hit the same 95 absolute peak at idle but mostly more like 93ish, if you are really worried about overheating just lower your fan on temp as this will actually do something where no thermostat even a 75c one can ever hope to help because it will be fully open long before your engine reaches peak coolant temp.
Thems the facts folks so don't be put off fitting an 88c thermostat, all its going to give you is faster warm up times, better heater performance in the cooler months when you need it, and an engine that will operate in the temperature window the designers of the fuel injection system intended.
This post is for the vast majority of good old Chimaeara owners who run their good old standard Rover V8 in their good old Chimaera on the road, track day types and the forced induction crowd should follow the more track focused spark plug and thermostat choices made by TVR. For the record TVR did get it right, its just somewhere along the way they forgot the vast majority of the cars they where building were actually going to be used on the road... not the race track!
If you put this engine in a light sports car it may well get down the road very well indeed, but not because your old Range Rover engine has suddenly and miraculously become a highly strung, high compression, high performance exotic power plant, its still an old Range Rover engine it's just moving around a lot less mass.
TVR definitely didn't know what they were doing when they fitted the temp sender in a blind spur or we wouldn't have needed this post, and they also didn't choose well when they selected NGK B7ECS spark plugs or it wouldn't be that so many have reported benefits by switching to a BPR6ES, the exact same spark pugs specified for the old Range Rover our old Rover V8 engine was directly lifted from by the way.
For the avoidance of any doubt I'm not talking about cammed up higher compression RV8 engine builds, supercharged or turbocharged engines, I'm talking to by far the vast majority who read these pages who I recommend fit an 88c thermostat. The vast majority who just like me use a good old TVR Chimaera on the road not the race track, a road car that carries what is essentially the same good old Rover V8 that in absolutely in every important respect is exactly what you got in a good old Range Rover.
Now, if you study the engine management system the vast majority of us run which of course is the exact same engine management system used on and designed for the the good old Range Rover engine you'll discover the very clever engineers who designed it intended the engine to run within a 85-95c window, of course it's up to every owner to choose if they ignore this.
The good old Range Rover and its good old Rover V8 as fitted to the average good old TVR Chimaera used on the road which fits the profile of the vast majority of us is an engine that was designed to run BPR6ES spark plugs an an 88c thermostat, indeed the value of the thermostat is one of the critical components that not only makes up the cooling system its and equally critical component in the Lucas14CUX fuel injection system.
Of course despite the fact the highly qualified engineers at Land Rover would have conducted extensive reliability testing of the good old Rover V8 engine with an 88c thermostat in engine testing facilities that would have made the whole TVR company look like a shed at the bottom of your garden I would still never recommend an 88c thermostat to my TVR friends unless I myself had completed my own testing and seen clear benefits with absolutely no risks or downsides.
So for anyone still questioning what Land Rover specified for the good old Rover V8 and if its the right choice for your good old Chimaera that runs the same good old low compression Rover V8, I'm here to tell you I've run the 88c thermostat for some six years now and over tens of thousands of miles.
For the record my TVR does not live under a cover in the back of the workshop 90% of the year doing next to no miles every year, my TVR gets used almost every day of the week in all road conditions and all weathers. Time and time again my good old Rover V8 engine with its 88c thermostat has seen ambient temperatures soar to over 100 degrees Fahrenheit while stop start creeping along in horrific traffic jams in the South of France and Itally.
Also keep in mind my 88c thermostat equipped TVR runs on hot burning LPG that has none of the cooling effects of petrol, so if you're still not sure the engineers at Land Rover knew what they were doing when they specified an 88c thermostat for the good old Rover V8 as fitted to the vast majority of good old road driven Chimaeras don't worry, I've done six years and tens of thousand of miles of additional exhaustive and intensive stress testing of my engine fitted with an 88c thermostat and I'm hear to 100% reassure you all there are absolutely no risks whatsoever.
Now if we focus on the dreaded overheating condition for a moment of course it doesn't matter a jot if you fit a 75c, 82c or an 88c thermostat, because the fact is your peak temperature when you actually run the risk of overheating is still going to be the exact same 95c because all these example thermostat values will be fully open well below 90c, so all of them will be doing absolutely nothing to assist engine cooling at idle to save you from overheating.
Remember engines don't tend to to overheat when you're just driving about, air flow through your radiator sees to that, liquid cooled engines tend to overheat at idle which is why we tend to see this happen in traffic jams. To be clear if you fit an 82c thermostat you'll be driving about at 80-82c so the only difference when driving about on an 88c thermostat is you'll see 85-88c and both will hit the same 95 absolute peak at idle but mostly more like 93ish, if you are really worried about overheating just lower your fan on temp as this will actually do something where no thermostat even a 75c one can ever hope to help because it will be fully open long before your engine reaches peak coolant temp.
Thems the facts folks so don't be put off fitting an 88c thermostat, all its going to give you is faster warm up times, better heater performance in the cooler months when you need it, and an engine that will operate in the temperature window the designers of the fuel injection system intended.
This post is for the vast majority of good old Chimaeara owners who run their good old standard Rover V8 in their good old Chimaera on the road, track day types and the forced induction crowd should follow the more track focused spark plug and thermostat choices made by TVR. For the record TVR did get it right, its just somewhere along the way they forgot the vast majority of the cars they where building were actually going to be used on the road... not the race track!
Edited by ChimpOnGas on Friday 9th August 08:05
I agree with both COG and Sardonicus 
For the vast majority of people who don't often use their car in anger then the hotter stat is good, for those who regularly track or thrash their car then something cooler will be good. I guess once you've got all the info you can make an informed choice about what will work best for you and your driving style.
Good info posted by all.
On a point for Lucas users though .. the ecu only learns a long term trim at hot idle (over 85C) and so people who have fitted a lower stat AND fan switch will be reducing the chances on the long term trim taking effect.
I mentioned this to John Ravenscroft once when I was with him with a car from my Harrogate HC days . We were sat in a chimaera on road test waiting for the long term trim to react and I commented on the lower stat and fan switch preventing the long term trim updating more often.
Just a small point but worth bearing in mind if you have a lower fan temp switch.
For the vast majority of people who don't often use their car in anger then the hotter stat is good, for those who regularly track or thrash their car then something cooler will be good. I guess once you've got all the info you can make an informed choice about what will work best for you and your driving style.
Good info posted by all.
On a point for Lucas users though .. the ecu only learns a long term trim at hot idle (over 85C) and so people who have fitted a lower stat AND fan switch will be reducing the chances on the long term trim taking effect.
I mentioned this to John Ravenscroft once when I was with him with a car from my Harrogate HC days . We were sat in a chimaera on road test waiting for the long term trim to react and I commented on the lower stat and fan switch preventing the long term trim updating more often.
Just a small point but worth bearing in mind if you have a lower fan temp switch.
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