Trying to get an accurate water temperature reading
Discussion
I am trying to calibrate my water temperature gauge for the Range Rover sender with an IR gun.
Thought the area just around the otter switch was a sensible place and the fans switched on and off at a measured 92 & 87 deg respectively as the car warmed up on tickover from cold.
I then took the car out for a 'spirited' short drive and when I got back, measuring again at the same place found the fans switching on and off for a similar length of time as before but the readings were between 105-110 deg. I suspect this may be because of heat coming off the manifolds affecting the readings.
The otter switch seems to be working in that the fans are coming on and off but where is there on the car that I can get a better reading?
I have a Rovergauge and know that also measures temp, but I want to check that that is also working correctly.
Thought the area just around the otter switch was a sensible place and the fans switched on and off at a measured 92 & 87 deg respectively as the car warmed up on tickover from cold.
I then took the car out for a 'spirited' short drive and when I got back, measuring again at the same place found the fans switching on and off for a similar length of time as before but the readings were between 105-110 deg. I suspect this may be because of heat coming off the manifolds affecting the readings.
The otter switch seems to be working in that the fans are coming on and off but where is there on the car that I can get a better reading?
I have a Rovergauge and know that also measures temp, but I want to check that that is also working correctly.
That's very useful information, thanks.
How likely is it that the ECU sender be inaccurate, ie, if it is not very likely,then I will just use the Rovergauge + variable resistor to find the point on the guage where the temperature reads, say 92 deg, to correspond with the starting of the fans.
A query though, even if the fans come on at 92 deg, how likely is it for a system that is 'working properly' to carry on heating up to say 100 deg and staying up there, regardless of the fans being on? Is there a limit to the cooling capability of the twin fans?
In the case I described in my first post, the fans were cutting on and off even though the gauge, and my 'readings' were over the 92-87 deg range of assisted cooling.
How likely is it that the ECU sender be inaccurate, ie, if it is not very likely,then I will just use the Rovergauge + variable resistor to find the point on the guage where the temperature reads, say 92 deg, to correspond with the starting of the fans.
A query though, even if the fans come on at 92 deg, how likely is it for a system that is 'working properly' to carry on heating up to say 100 deg and staying up there, regardless of the fans being on? Is there a limit to the cooling capability of the twin fans?
In the case I described in my first post, the fans were cutting on and off even though the gauge, and my 'readings' were over the 92-87 deg range of assisted cooling.
After using a variable resistor, I found that the closest was around 120 ohm to read the gauge at 92 deg, when the fans kicked in. The problem is I am driving around and the gauge is showing between 90 deg and about 98.
I will check it against the Rovergauge while driving around to see what the ECU sender thinks the temperature is.
I have a couple of more modern cars, whose temp gauges do not budge from the middle setting whether you are driving up a cliff or down it, and a 320CE cabrio where the temp gauge goes up and down all the time. But at least you know it is right so you dont worry about it.
I cant understand why TVR were so relaxed about what is a major issue on an engine that generates so much heat, with a cat sat in front of it, that they didnt think to get this one part right.
I will check it against the Rovergauge while driving around to see what the ECU sender thinks the temperature is.
I have a couple of more modern cars, whose temp gauges do not budge from the middle setting whether you are driving up a cliff or down it, and a 320CE cabrio where the temp gauge goes up and down all the time. But at least you know it is right so you dont worry about it.
I cant understand why TVR were so relaxed about what is a major issue on an engine that generates so much heat, with a cat sat in front of it, that they didnt think to get this one part right.
That's right we are in Cyprus and the car is handling the heat really well considering it is usually what you had in the UK for a few days, all summer here.
The car hasn't overheated yet and so far it is not looking likely to, I just want to be better informed about the state of coolant temperature and where the limits actually are.
The car hasn't overheated yet and so far it is not looking likely to, I just want to be better informed about the state of coolant temperature and where the limits actually are.
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