Water Temperature reading 61 Degrees when cold in garage!
Discussion
I noticed my temperature sensor was overreading while sitting in the garage with the engine off. I purchases a new sensor. But before fitting I confirmed the fault, then slaved in the new sensor, both read 61 degrees. The ECU sensor was reading (off the laptop) ambient temperature at 14 degrees. With the sensor disconnected the instrument pod was reading 48 degrees. With the main bulkhead plug disconnected, the pod was still reading 48 degrees. I have checked all the ribbon connectors to the pod and they all look OK. Any suggestions? should I change all the ribbon connectors, or is there further fault finding I should be doing first?
If the duff indication has 'just' happened....previously reading normally?...That kinda suggests that the wiring is sound?
I've posted before on the failure of the DASH coolant temp' indication on my car.
Upshot was that I had 4 different sensors supplied before I got one that worked. TVR Parts and RaceTech were the suppliers and were both very helpful when I fed back the weird behaviour/failure mode of the sensors
It was Gordy at Str8Six that advised that a bad batch of sensors was in circulation and to go back to the suppliers to replace....but you tend to get a bit concerned - particularly after the 4th attempt!!
Hope you get it sorted.
Nick
I've posted before on the failure of the DASH coolant temp' indication on my car.
Upshot was that I had 4 different sensors supplied before I got one that worked. TVR Parts and RaceTech were the suppliers and were both very helpful when I fed back the weird behaviour/failure mode of the sensors
It was Gordy at Str8Six that advised that a bad batch of sensors was in circulation and to go back to the suppliers to replace....but you tend to get a bit concerned - particularly after the 4th attempt!!
Hope you get it sorted.
Nick
Thanks Nick. I read that from your post, and I did wonder, especially as i got the sensor from Racing Green. But the one interesting point is if I disconnect the sensor (ie open circuit) I still get 48 degrees.
Can anyone tell me what their's read on dash if the sensor is disconnected
Can anyone tell me what their's read on dash if the sensor is disconnected
s3dave said:
Thanks Nick. I read that from your post, and I did wonder, especially as i got the sensor from Racing Green. But the one interesting point is if I disconnect the sensor (ie open circuit) I still get 48 degrees.
Can anyone tell me what their's read on dash if the sensor is disconnected
....From memory, when I pulled the electrical plug on mine (prior to changing the [duff] sensor) the dash indication went to zero. I guess the "61 degrees" your seeing is with ignition 'ON'?Can anyone tell me what their's read on dash if the sensor is disconnected
Nick
s3dave said:
Thanks Nick. Yes ignition on. This morning with multiplug disconnected it's reading 36 degrees (with both old and new sensor connected it's reading 42 degrees).
OK - wondered if you've sorted this.With my basic(!!??) understanding of what's happening, I can only guess that somewhere in the engine loom you have a (slightly varying) resistance that is indicated by the readings of 40-60 deg.?
It's not unheard of that, with the passage of time and heat cycles, the engine loom starts to fail. I had this on my car, resulting in very poor pick-up under acceleration. On the diagnostics, the ignition advance was not increasing as revs increased. It took a couple of attempts before Str8Six replaced the engine loom and that sorted it.
When I had the dash indication woes, I was advised to do a continuity check - but my logic said that 1) loom was quite new. and, 2) I had readings up to an indicated 92~94 degC, (showing that loom was continuous) and then it would fail/go open circuit...the first one or two sensors would, after a time, then read normally.
Might be time to get the multi-meter out and pin to test resistance along the length of the wire to the bulkhead connector?
Nick
Nick. Still not fixed. You may be right, but not in the engine loom, but maybe the car loom. With the multiplug disconnected I still get a reading of 36 degrees (ie engine loom disconnected). I checked the earths and they seem ok. Not looking forward to trying to hang upside down to do continually checks under dash (or potentially remove the whole dash).
I took the car out today with my laptop connected to the diagnostic port. The car ran well with ECU water temp reading when warm around 86-88 degrees with fan coming on occasionally but the dash was reading around 97, but the delta was not consistent - 10 degrees higher when hot, but over-reading by more than 20 degrees when cold.
I took the car out today with my laptop connected to the diagnostic port. The car ran well with ECU water temp reading when warm around 86-88 degrees with fan coming on occasionally but the dash was reading around 97, but the delta was not consistent - 10 degrees higher when hot, but over-reading by more than 20 degrees when cold.
Hi Dave. Don't you just love'em!
My dash reading failed whilst driving down to Clermont-Ferrand 3 or 4 years ago...started going cranky - zero, then reading - then Code A on dash.
However, I reasoned that I had some 'inferred' data via the oil temp. reading and the engine was running normally. Arriving at Clermont in heavy rush hour traffic, I listened for the radiator fans cutting in and out...which they did. Therefore the (crucial) input to the ECU was good, so I felt confident to continue with the remainder of the holiday.
Good luck with your efforts! Nick
My dash reading failed whilst driving down to Clermont-Ferrand 3 or 4 years ago...started going cranky - zero, then reading - then Code A on dash.
However, I reasoned that I had some 'inferred' data via the oil temp. reading and the engine was running normally. Arriving at Clermont in heavy rush hour traffic, I listened for the radiator fans cutting in and out...which they did. Therefore the (crucial) input to the ECU was good, so I felt confident to continue with the remainder of the holiday.
Good luck with your efforts! Nick
Temp issue fixed. Just to close the loop for anyone in the future.
Symptoms: dash temperature reading over 60 degrees while car was in the garage with engine off.
Solution: Temp sensor changed but issue still present. Dash ECU was sent back to Paul Smith but No Fault Found. Since then on everyone's advice I have been looking for an earth issue. Then last month the fan would only work intermittently. I found if I pressed my thumb on the centre of the Dash ECU, the HVAC fan would work. Again dash ECU sent back to Paul Smith. He found the issue with the fan control and while again he could not reproduce any temp indication issues he change a component "on spec". Great news, the dash temp is now indicating correctly. Many thanks to Paul for a quick turnaround and repair of the dash ECU (I hope he never retires!).
Symptoms: dash temperature reading over 60 degrees while car was in the garage with engine off.
Solution: Temp sensor changed but issue still present. Dash ECU was sent back to Paul Smith but No Fault Found. Since then on everyone's advice I have been looking for an earth issue. Then last month the fan would only work intermittently. I found if I pressed my thumb on the centre of the Dash ECU, the HVAC fan would work. Again dash ECU sent back to Paul Smith. He found the issue with the fan control and while again he could not reproduce any temp indication issues he change a component "on spec". Great news, the dash temp is now indicating correctly. Many thanks to Paul for a quick turnaround and repair of the dash ECU (I hope he never retires!).
Edited by s3dave on Saturday 29th April 22:47
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