Range Rover Temp Sender Thread Size?
Discussion
Interesting discussion on thermostats gents.
I think it brings us full circle to the theme of this thread.
If the standard set-up works i.e. the stock thermostat and otter switch etc - as evident by IR thermometers, then the villain of the peace is the errant location of the original sender - meaning that the gauge doesn't read accurately.
With no means of knowing if the temp gauge wasn't reading accurately, you'd condemn the rest of the cooling system either by fitting a lower range otter switch or thermostat.
Case in point - my Chim would run at an indicated 100deg and even read off the scale in traffic. Naturally this caused a lot of worry until a TVR specialist told me the gauge was over-reading by around 15deg!
No wonder the PO fitted a 74deg stat in a bid to make the car run cooler!
With the COG sender fitted, I have complete confidence in the cooling system (and gauge).
I think it brings us full circle to the theme of this thread.
If the standard set-up works i.e. the stock thermostat and otter switch etc - as evident by IR thermometers, then the villain of the peace is the errant location of the original sender - meaning that the gauge doesn't read accurately.
With no means of knowing if the temp gauge wasn't reading accurately, you'd condemn the rest of the cooling system either by fitting a lower range otter switch or thermostat.
Case in point - my Chim would run at an indicated 100deg and even read off the scale in traffic. Naturally this caused a lot of worry until a TVR specialist told me the gauge was over-reading by around 15deg!
No wonder the PO fitted a 74deg stat in a bid to make the car run cooler!
With the COG sender fitted, I have complete confidence in the cooling system (and gauge).
Just to wrap this thermostat business up its important to understand for those still running the Lucas 14CUX the thermostat is an important component integral to the correct functioning of this sophisticated electronic fuel injection system, and the thermostat value specified when the system was designed for the Rover V8 engine was 88c.
On page 26 of the factory cooling system manual it clearly states the value of the thermostat is 88c and outlines the testing procedure to check it is correctly functioning within a window of 85 - 89c.
This is further supported by the following factory thermostat spec that also included the Morgan Plus 8.
Now if you go to the factory fuel injection manual covering the Lucas 14CUX Hotwire system there is clear instruction that all checks must be completed with the coolant temperature between 80c - 95c, clearly this tells us this is the correct operating temperature window for the engine when warm and even more critically what the fuel injection system expects to see from a warm engine and considers the optimum operating temperature window.
It's quite clear operating the engine outside of this 80c - 95c window specified by the designers of 14CUX fuel system is not recommended, lower than 80c and the 14CUX will very likely still be applying a level of cold start enrichment and going above 95c is considered above the safe threshold and optimal 15c operating window.
Further more Mark Adams contributes the following in the ACT website....
"It is essential that the coolant thermostat is working correctly, especially on catalyst-equipped cars. The fuel injection system is optimised to provide accurate mixture control within normal temperature ranges."
And of course we now know from the factory fuel injection manual covering the Lucas 14CUX Hotwire system that the 'normal' temperature range is 80c - 95c.
Mark Adams goes on to sate....
"In the case of catalyst-equipped vehicles Oxygen/Lambda control does not start until the engine has reached 70 degrees Centigrade, therefore the absence of a thermostat may cause terminal cat damage."
https://www.actproducts.co.uk/2011/lucas-14cux-fue...
As previously stated the function of a thermostat is to help the engine reach its optimum operating temperature as quickly as possible which we now know to be 80c - 95c as specified by the engine manufacturer and critically the designers of the electronic fuel injection system that feeds it.
We also now know to achieve the 80c - 95c optimum operating temperature Land Rover working in partnership Lucas specified an 88c thermostat, this is what I mean when I say the thermostat is a an important component integral to the correct functioning of the electronic fuel injection system.
Of course it's entirely up to the readers of this post if they decide they know better and choose to ignore the fact an 88c thermostat was specified and the 80c - 95c optimum operating temperature window was clearly laid out by the engine manufacturer and the designers of the electronic fuel injection system, but be aware the 14CUX while very out of date by modern standards is still actually a very sophisticated system and for it to work correctly it needs to operate as designed.
Despite the fact the thermostat value the designers specified was 88c I'm not here to tell you you absolutely must fit an 88c thermostat, all I'm doing is presenting the component and operating specifications clearly communicated by the designers and manufacturers of the system. With this unarguable factual evidence laid before us you can of course choose to do with it what you will, but personally I'd recommend paying close attention to what the manufacturers of the engine and the designers of the electronic fuel injection system are saying/specifying because one thing is for sure..... they're not publishing this information for fun
At least with the TT6811-03 temp sender fitted you'll finally easily and reliably be able to see if you are operating your engine inside or outside of the important 80c - 95c optimum operating temperature window Land Rover and Lucas specified, as such I now feel my attempts to help the TVR Chimaera community on this one can be considered concluded.
Hope it helps chaps
On page 26 of the factory cooling system manual it clearly states the value of the thermostat is 88c and outlines the testing procedure to check it is correctly functioning within a window of 85 - 89c.
This is further supported by the following factory thermostat spec that also included the Morgan Plus 8.
Now if you go to the factory fuel injection manual covering the Lucas 14CUX Hotwire system there is clear instruction that all checks must be completed with the coolant temperature between 80c - 95c, clearly this tells us this is the correct operating temperature window for the engine when warm and even more critically what the fuel injection system expects to see from a warm engine and considers the optimum operating temperature window.
It's quite clear operating the engine outside of this 80c - 95c window specified by the designers of 14CUX fuel system is not recommended, lower than 80c and the 14CUX will very likely still be applying a level of cold start enrichment and going above 95c is considered above the safe threshold and optimal 15c operating window.
Further more Mark Adams contributes the following in the ACT website....
"It is essential that the coolant thermostat is working correctly, especially on catalyst-equipped cars. The fuel injection system is optimised to provide accurate mixture control within normal temperature ranges."
And of course we now know from the factory fuel injection manual covering the Lucas 14CUX Hotwire system that the 'normal' temperature range is 80c - 95c.
Mark Adams goes on to sate....
"In the case of catalyst-equipped vehicles Oxygen/Lambda control does not start until the engine has reached 70 degrees Centigrade, therefore the absence of a thermostat may cause terminal cat damage."
https://www.actproducts.co.uk/2011/lucas-14cux-fue...
As previously stated the function of a thermostat is to help the engine reach its optimum operating temperature as quickly as possible which we now know to be 80c - 95c as specified by the engine manufacturer and critically the designers of the electronic fuel injection system that feeds it.
We also now know to achieve the 80c - 95c optimum operating temperature Land Rover working in partnership Lucas specified an 88c thermostat, this is what I mean when I say the thermostat is a an important component integral to the correct functioning of the electronic fuel injection system.
Of course it's entirely up to the readers of this post if they decide they know better and choose to ignore the fact an 88c thermostat was specified and the 80c - 95c optimum operating temperature window was clearly laid out by the engine manufacturer and the designers of the electronic fuel injection system, but be aware the 14CUX while very out of date by modern standards is still actually a very sophisticated system and for it to work correctly it needs to operate as designed.
Despite the fact the thermostat value the designers specified was 88c I'm not here to tell you you absolutely must fit an 88c thermostat, all I'm doing is presenting the component and operating specifications clearly communicated by the designers and manufacturers of the system. With this unarguable factual evidence laid before us you can of course choose to do with it what you will, but personally I'd recommend paying close attention to what the manufacturers of the engine and the designers of the electronic fuel injection system are saying/specifying because one thing is for sure..... they're not publishing this information for fun
At least with the TT6811-03 temp sender fitted you'll finally easily and reliably be able to see if you are operating your engine inside or outside of the important 80c - 95c optimum operating temperature window Land Rover and Lucas specified, as such I now feel my attempts to help the TVR Chimaera community on this one can be considered concluded.
Hope it helps chaps
I don't think anyone is questioning the accuracy of the information for a Range Rover.
But we all drive TVR's, who's engines (at least the larger versions) were modified significantly by TVR and who specified a 82C thermostat as standard, no doubt for good reason. Suggest a call to Dom at Powers, who both built many V8's for TVR and now runs Powers Performance would be able to explain the rationale.
BTW Caterham Cars can also supply the sender under part number 71167 for about £20 delivered if you only want to buy one.
But we all drive TVR's, who's engines (at least the larger versions) were modified significantly by TVR and who specified a 82C thermostat as standard, no doubt for good reason. Suggest a call to Dom at Powers, who both built many V8's for TVR and now runs Powers Performance would be able to explain the rationale.
BTW Caterham Cars can also supply the sender under part number 71167 for about £20 delivered if you only want to buy one.
I personally feel that a RV8 is a RV8 and their temp requirements remain the same. More power?....just need better cooling effiency to maintain the optimum temp range.
Rover states 88degrees and that's what my new thermostats rated at for my GEMS.
Thanks for ALL your work COG, I'll be getting the correct sender some time soon.
Rover states 88degrees and that's what my new thermostats rated at for my GEMS.
Thanks for ALL your work COG, I'll be getting the correct sender some time soon.
I’d never really question the words of manufacturer info until proven otherwise but I would point out the engines in Tvr probably errr get a lot more stick at higher revs than the vehicles these manuals were written for so keeping oil at workable temps vital and possibly why a lower temp stat was fitted to the 5.0 cars as part of a crude attempt.
It’s all nonsense as if your fans are doing there job and your not thrashing it temps will stay in the correct operating window and once hot the lower tamp stat won’t help anyway.
An oil cooler should have been fitted from new imo but saying that there’s lots of standard cars running well to this day.
I’d like to see how well this new mod does with a long wait sat in traffic, say 40 mins at least, see if heat soak and hot wiring effect the readings in anyway.
Using the standard gauge I’ve had my car sat in a garage running for at least that long with Mbe software showing a rock solid 88/89 with fans doing the job and always going off, gauge accurate until engine bay very warm, took about 40 mind then crept upto about 105. Not at anytime did the software read anything other than the figures stated above. They rarely overheat in normal operation.
Once we know this mod can take serious heat for long periods of slow or stationary running it’s a winner
It’s all nonsense as if your fans are doing there job and your not thrashing it temps will stay in the correct operating window and once hot the lower tamp stat won’t help anyway.
An oil cooler should have been fitted from new imo but saying that there’s lots of standard cars running well to this day.
I’d like to see how well this new mod does with a long wait sat in traffic, say 40 mins at least, see if heat soak and hot wiring effect the readings in anyway.
Using the standard gauge I’ve had my car sat in a garage running for at least that long with Mbe software showing a rock solid 88/89 with fans doing the job and always going off, gauge accurate until engine bay very warm, took about 40 mind then crept upto about 105. Not at anytime did the software read anything other than the figures stated above. They rarely overheat in normal operation.
Once we know this mod can take serious heat for long periods of slow or stationary running it’s a winner
I totally understand it's tempting to believe our engines are significantly different from the Rover V8 fitted to a Range Rover or Discovery, but the truth is this just isn't the case, in all the important aspects and perhaps with the exception of the stroked 5.0 litre a Rover V8 in a TVR is really no different to those installed in the Land Rover vehicles.
Even the 5.0 litre has the exact same architecture, water jacket volumes, water pump, and as we all know the radiator TVR used on Chimaeras was just a Range Rover rad with some very minor changes to the hose outlet angles. Ok so compression ratio is going to have a bearing on heat production for sure, but I've said it hundred times now so I'll say it again... "the peak coolant temperature seen by your engine (no matter which capacity it is) will always be after the thermostat (even an 88c thermostat) has fully opened".
Once this is understood you'll soon realise why you can not solve overheating issues with a lower value thermostat, FACT!
When the fans chime in on your Chimaera the coolant will be at 90c and will reach an absolute maximum of 95c before the fans help bring the coolant temp down to roughly 86c, a 5.0 litre fitted with a low value thermostat is still going to hit that absolute maximum of 95c because all the thermostats being discussed here up to and including the correct 88c one will be fully open at the 90c fan activation point.
Now we know you can't solve overheating with a lower value thermostat we need to understand all you're going to do when you fit a lower value thermostat is force the engine to take longer to warm up to it's correct 80c - 95c operating window and in the winter months run cooler than the minimum 80c out on the open road when driving at speed, however if you fit the correct 88c thermostat your engine even on a warm day will run at a consistent 86/87c which is absolutely perfect and running 86/87c is of course totally safe and exactly what the 14CUX expects to see from a fully warmed engine!
With the correct 88c thermostat fitted your ECU will be managing the fuel metering and idle behaviour precisely as it's designers intended, at this point we should not kid ourselves, it's important we all accept while some chipping of the ECU went on at TVR this only really made small changes to the fuel map. The chips used by TVR did not alter the fact the 14CUX ECU is still looking to identify a fully warmed engine condition by virtue of the coolant temperature being within the 80c - 95c window as clearly laid out in the factory fuel injection manual, this critical perimeter is embedded within the core workings of the ECU does not change one bit by fitting a fuel chip!
So if you fit a lower value thermostat you're not protecting your engine from liner slip or overheating, all you're doing is forcing the engine to take longer to reach this very important 80c - 95c coolant temp window that tells the ECU to come out of cold start enrichment and that the engine is not exceeding 95c.
What also tends to happen with an 82c thermostat is you'll see a true 80c - 83c on a warm day when driving at speed which is actually fine, however come the cooler months the coolant tends to take for ever to get there and indeed what you typically see is 75c which is well below the 80c low limit of the correct operating temp the ECU uses to determine the engine is in its fully warmed running condition.
I've run both an 82c thermostat and and the correct 88c thermostat and I can 100% guarantee you the 88c thermostat gives better results, by switching from an 82c to an 88c thermostat you'll exchange 82c for 86c when driving at speed during the summer months, this 4c difference makes absolutely fek all difference so there are no disadvantages to running an 88c thermostat... FACT!
Where the totally summer safe 88c thermostat comes into its own is when ambient temps stat to cool a little, this will typically be from the autumn months on but even during the summer if you drive your TVR at night you'll immediately start to see the benefits of switching to the correct 88c thermostat. During cooler ambient temps with an 82c thermostat you will definitely suffer sub 80c running temps at speed which puts you outside what the ECU interprets as a fully warmed engine, and for heavens sake don't fit a 74 degree thermostat what ever you do.
Even with my 88c thermostat fitted my coolant temp will fall to 81c when on the motorway on a really cold day but the engine warms up so much faster than with my old 82c thermostat and unlike the 82c thermostat coolant temps never dip below the all important 80c lower threshold.
So there are no disadvantages in fitting the correct 88c thermostat, only benefits!
TVR may well have supplied the Chimaera with an 82c thermostat but they also fitted the engine with way too cool and highly inappropriate shrouded electrode NGK B7ECS, these two choices may be perfect if you're endurance racing and probably came as a consequence of what was needed on the Tuscan Challenge cars, but the uncomfortable truth is despite the fact as TVR owners we all think we are race car driving Gods we are just not using our cars the way a Tuscan Challenge TVR got used.
The 82c thermostat and highly inappropriate way too cool shrouded electrode NGK B7ECS spark plugs used by TVR is why we so often see this....
What we are seeing here is an NGK B7ECS spark plug that being a No7 is simply not getting hot enough to self clean, we are almost certainly also seeing it the problem has compounded by the fact the coolant is not reaching the 80c - 95c window so the ECU is still applying the last stages of cold start enrichment and is a classic symptom of the too lower value thermostat syndrome.
Change the plugs to a No6, and a set of good old cheap as chips BPR6ES plugs are just fine, then replace that 82c thermostat with the correct value 88c one and all this plug fouling goes away in an instant. Your TVR will idle better, run smother out on the open road and use less fuel, finally with your new found improved combustion efficiency will come more power too.
The reality is 99.9% of us drive our TVR Chimaeras on the road 99% of the time, we are not out there campaigning in the Tuscan Challenge going balls out a wide open throttle, we are driving normally on the public highway where we will inevitably experience periods at idle and everything in between. If you are choosing components for a race car they will be very different from those that deliver optimum performance on the road, you now just need to be honest with yourself as to the genuine type of driving to actually do and admit you yourself the Rover V8 in your TVR and the 14CUX electronic fuel injection system that meters fuel to it is really 99.8% all Rage Rover/Discovery.
All this may not be what the TVR community wants to hear, but thems the facts folks!
Even the 5.0 litre has the exact same architecture, water jacket volumes, water pump, and as we all know the radiator TVR used on Chimaeras was just a Range Rover rad with some very minor changes to the hose outlet angles. Ok so compression ratio is going to have a bearing on heat production for sure, but I've said it hundred times now so I'll say it again... "the peak coolant temperature seen by your engine (no matter which capacity it is) will always be after the thermostat (even an 88c thermostat) has fully opened".
Once this is understood you'll soon realise why you can not solve overheating issues with a lower value thermostat, FACT!
When the fans chime in on your Chimaera the coolant will be at 90c and will reach an absolute maximum of 95c before the fans help bring the coolant temp down to roughly 86c, a 5.0 litre fitted with a low value thermostat is still going to hit that absolute maximum of 95c because all the thermostats being discussed here up to and including the correct 88c one will be fully open at the 90c fan activation point.
Now we know you can't solve overheating with a lower value thermostat we need to understand all you're going to do when you fit a lower value thermostat is force the engine to take longer to warm up to it's correct 80c - 95c operating window and in the winter months run cooler than the minimum 80c out on the open road when driving at speed, however if you fit the correct 88c thermostat your engine even on a warm day will run at a consistent 86/87c which is absolutely perfect and running 86/87c is of course totally safe and exactly what the 14CUX expects to see from a fully warmed engine!
With the correct 88c thermostat fitted your ECU will be managing the fuel metering and idle behaviour precisely as it's designers intended, at this point we should not kid ourselves, it's important we all accept while some chipping of the ECU went on at TVR this only really made small changes to the fuel map. The chips used by TVR did not alter the fact the 14CUX ECU is still looking to identify a fully warmed engine condition by virtue of the coolant temperature being within the 80c - 95c window as clearly laid out in the factory fuel injection manual, this critical perimeter is embedded within the core workings of the ECU does not change one bit by fitting a fuel chip!
So if you fit a lower value thermostat you're not protecting your engine from liner slip or overheating, all you're doing is forcing the engine to take longer to reach this very important 80c - 95c coolant temp window that tells the ECU to come out of cold start enrichment and that the engine is not exceeding 95c.
What also tends to happen with an 82c thermostat is you'll see a true 80c - 83c on a warm day when driving at speed which is actually fine, however come the cooler months the coolant tends to take for ever to get there and indeed what you typically see is 75c which is well below the 80c low limit of the correct operating temp the ECU uses to determine the engine is in its fully warmed running condition.
I've run both an 82c thermostat and and the correct 88c thermostat and I can 100% guarantee you the 88c thermostat gives better results, by switching from an 82c to an 88c thermostat you'll exchange 82c for 86c when driving at speed during the summer months, this 4c difference makes absolutely fek all difference so there are no disadvantages to running an 88c thermostat... FACT!
Where the totally summer safe 88c thermostat comes into its own is when ambient temps stat to cool a little, this will typically be from the autumn months on but even during the summer if you drive your TVR at night you'll immediately start to see the benefits of switching to the correct 88c thermostat. During cooler ambient temps with an 82c thermostat you will definitely suffer sub 80c running temps at speed which puts you outside what the ECU interprets as a fully warmed engine, and for heavens sake don't fit a 74 degree thermostat what ever you do.
Even with my 88c thermostat fitted my coolant temp will fall to 81c when on the motorway on a really cold day but the engine warms up so much faster than with my old 82c thermostat and unlike the 82c thermostat coolant temps never dip below the all important 80c lower threshold.
So there are no disadvantages in fitting the correct 88c thermostat, only benefits!
TVR may well have supplied the Chimaera with an 82c thermostat but they also fitted the engine with way too cool and highly inappropriate shrouded electrode NGK B7ECS, these two choices may be perfect if you're endurance racing and probably came as a consequence of what was needed on the Tuscan Challenge cars, but the uncomfortable truth is despite the fact as TVR owners we all think we are race car driving Gods we are just not using our cars the way a Tuscan Challenge TVR got used.
The 82c thermostat and highly inappropriate way too cool shrouded electrode NGK B7ECS spark plugs used by TVR is why we so often see this....
What we are seeing here is an NGK B7ECS spark plug that being a No7 is simply not getting hot enough to self clean, we are almost certainly also seeing it the problem has compounded by the fact the coolant is not reaching the 80c - 95c window so the ECU is still applying the last stages of cold start enrichment and is a classic symptom of the too lower value thermostat syndrome.
Change the plugs to a No6, and a set of good old cheap as chips BPR6ES plugs are just fine, then replace that 82c thermostat with the correct value 88c one and all this plug fouling goes away in an instant. Your TVR will idle better, run smother out on the open road and use less fuel, finally with your new found improved combustion efficiency will come more power too.
The reality is 99.9% of us drive our TVR Chimaeras on the road 99% of the time, we are not out there campaigning in the Tuscan Challenge going balls out a wide open throttle, we are driving normally on the public highway where we will inevitably experience periods at idle and everything in between. If you are choosing components for a race car they will be very different from those that deliver optimum performance on the road, you now just need to be honest with yourself as to the genuine type of driving to actually do and admit you yourself the Rover V8 in your TVR and the 14CUX electronic fuel injection system that meters fuel to it is really 99.8% all Rage Rover/Discovery.
All this may not be what the TVR community wants to hear, but thems the facts folks!
Classic Chim said:
I’d never really question the words of manufacturer info until proven otherwise but I would point out the engines in Tvr probably errr get a lot more stick at higher revs than the vehicles these manuals were written for so keeping oil at workable temps vital and possibly why a lower temp stat was fitted to the 5.0 cars as part of a crude attempt.
It’s all nonsense as if your fans are doing there job and your not thrashing it temps will stay in the correct operating window and once hot the lower tamp stat won’t help anyway.
An oil cooler should have been fitted from new imo but saying that there’s lots of standard cars running well to this day.
I’d like to see how well this new mod does with a long wait sat in traffic, say 40 mins at least, see if heat soak and hot wiring effect the readings in anyway.
Using the standard gauge I’ve had my car sat in a garage running for at least that long with Mbe software showing a rock solid 88/89 with fans doing the job and always going off, gauge accurate until engine bay very warm, took about 40 mind then crept upto about 105. Not at anytime did the software read anything other than the figures stated above. They rarely overheat in normal operation.
Once we know this mod can take serious heat for long periods of slow or stationary running it’s a winner
Did the mod couple of weeks ago used the car yesterday sat in very slow stationary traffic for about half an hour fans cutting in about 90 and off about 78 felt more confident with it than before but I do have an ally radIt’s all nonsense as if your fans are doing there job and your not thrashing it temps will stay in the correct operating window and once hot the lower tamp stat won’t help anyway.
An oil cooler should have been fitted from new imo but saying that there’s lots of standard cars running well to this day.
I’d like to see how well this new mod does with a long wait sat in traffic, say 40 mins at least, see if heat soak and hot wiring effect the readings in anyway.
Using the standard gauge I’ve had my car sat in a garage running for at least that long with Mbe software showing a rock solid 88/89 with fans doing the job and always going off, gauge accurate until engine bay very warm, took about 40 mind then crept upto about 105. Not at anytime did the software read anything other than the figures stated above. They rarely overheat in normal operation.
Once we know this mod can take serious heat for long periods of slow or stationary running it’s a winner
Tony91 said:
Did the mod couple of weeks ago used the car yesterday sat in very slow stationary traffic for about half an hour fans cutting in about 90 and off about 78 felt more confident with it than before but I do have an ally rad
Excellent. Slightly curious why your fans would stay on until temps down to 78 as mine hovers around 88/89 with fans coming on/off every few minutes but I use a different Ecu.
The TVR one is a spade connector.
The Range Rover one is a round prong.
The new one for the Range Rover hole is a spade connector.
Problem solved.
I had the resistor fitted on my car to use the RR sender, but it had a spade to round adaptor in the kit. Without a resistor, you wouldn’t be using the RR sender.
The Range Rover one is a round prong.
The new one for the Range Rover hole is a spade connector.
Problem solved.
I had the resistor fitted on my car to use the RR sender, but it had a spade to round adaptor in the kit. Without a resistor, you wouldn’t be using the RR sender.
QBee said:
The TVR one is a spade connector.
The Range Rover one is a round prong.
The new one for the Range Rover hole is a spade connector.
Problem solved.
I had the resistor fitted on my car to use the RR sender, but it had a spade to round adaptor in the kit. Without a resistor, you wouldn’t be using the RR sender.
But the problem is that the original TVR sender is not a single spade connector, it is two small spades that fit into a plug socket connector as per photo belowThe Range Rover one is a round prong.
The new one for the Range Rover hole is a spade connector.
Problem solved.
I had the resistor fitted on my car to use the RR sender, but it had a spade to round adaptor in the kit. Without a resistor, you wouldn’t be using the RR sender.
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