Member Since: 29 Jan 2012
Location: Germany
Posts: 35
Temperature falling to below zero intermittently
Have since 4-5 weeks the following issue on my 2008 2.7TDV6 (German original) Discovery 3:
- starts up normal even around 0 degrees Celsius
- daily commute to school / office consists of circa 5min inner city driving and then 15 min driving at highway (between 100-140km/hr so revs are above 2000 rpm all the time)
- HVAC set at 21 degrees / no defrost
- FBH installed but not functioning at the moment (need to be taken out for inside cleaning)
- body-off took place in Feb21 when all belts / oil pump housing / brake lines / main gaskets were replaced
> after circa 8-10 min the temperature rises to about 1/4; and about 2-3min later to 1/2 (normal level)
> however during the drive on the highway, the temperature drops from 1/2 to below 0
> depending on the time left, the temperature slowly rises again to 1/2 (normal level)
> on longer trips on the highway this can happen in the first 30 min 1-2x in addition
Discovery 3 is with my LR independent and we have done the following:
- replaced the thermostat + renewed coolant
- replaced the coolant sensor
After replacing the thermostat and refilling with cooling fluid, the Discovery was put on idle running to fully flow the new coolant through the circuit and heat up the cabin (thus temperature on HVAC set on high). After about 10min, the engine started to sputter. Turns out there is Diesel in the connector for the fuel temperature sensor in the fuel return line. New return line setup incl. Temperature sensor is now on order
Questions that I have now:
- with new fuel return line + fuel temperature sensor, should I also renew the oil temperature sensor in the sump?
- would I need to test the injectors?
- any other causes the temperature dropping intermittently?
Many thanks for your thoughts / sharing your experiencesD5 HSE TDV6 (gone but not forgotten)
D3 HSE 60 Years Edition
D2 TD5 Highlander (gone but not forgotten)
8th Dec 2021 2:59 pm
rrhool
Member Since: 28 Aug 2014
Location: Norfolk
Posts: 4471
The engine temperature is dropping because your FBH is not working. The FBH is not just for starting, it will cut in intermittently to maintain the engine temperature.Richard
D3 SE 2007. Triumph 2.5Pi 1973. Ferguson TEA20 1948.
Discovery 2 4.0 ES 2001- Gone
Discovery 1 300Tdi ES '95 - Gone
Range Rover Classic '79 - Gone
8th Dec 2021 3:24 pm
Lee Trinder
Member Since: 12 Aug 2018
Location: Henley in arden
Posts: 515
Hi there, I had this on mine a couple of years ago, I was advised on here to change the oil temp sensor, been fine ever since. Cost about £30 and really east to change, especially if your changing the oil at the same time.
8th Dec 2021 8:04 pm
winmar
Member Since: 29 Jan 2012
Location: Germany
Posts: 35
Thanks for confirming my approach.D5 HSE TDV6 (gone but not forgotten)
D3 HSE 60 Years Edition
D2 TD5 Highlander (gone but not forgotten)
I had this. Yes bodsy recommended changing the oil temp sensor. Which fixed it. Easy job but do not over tighten the sensor!!! I did as I was using a big spanner. It breaks really easy .
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