Here's the issue.....this has happened a couple of times now - when driving, the temperature gauge will drop from half way to about a 1/4 and the viscous fan then kicks in. Eventually the gauge comes back up to normal operating temperature and the viscous fan cuts out.

When this happens - the bottom radiator hose is cold. I reckon that there is air in the system (recently converted to LPG so has had the radiator drained down and refilled)

I have bled the system as per the instructions on Topix, but I reckon there is still an air pocket

Any thoughts ?? Stolen / Gone: 2006MY Supercharged LPG Autobiography - Zambezi Silver with Sand/Jet/Jet Oxford Leather.....

Funny that, this happened to my S/C on Friday too, and I have LPG as well!

Out of interest do you get any any management lights on your car? Mine seems to come on with LPG, I ran a couple of tanks of petrol and it went out. The fault it comes up with is running lean, however when it's run with live diagnostics the figures show its not.

Also on mine, it was choking under full load, so I just had a second vapouriser fitted, which seems to have improved it a lot, but still EML.

I guess the lower temperature on the gauge shouldn't be a problem if it's not going into the danger zone, it's just unusual for it to not be dead centre when it's warmed up! Range Rover-less at the moment - Pining!

That's interesting that you have experienced the same issue as me.....

As for the LPG conversion, I haven't had any management light on (yet !!) Is your light on constantly ? Stolen / Gone: 2006MY Supercharged LPG Autobiography - Zambezi Silver with Sand/Jet/Jet Oxford Leather.....

I have investigated this a bit further but still can't get to the bottom of the problem.

If i drive the car from cold, soon after the temperature gauge gets to normal, it drops to just above the blue and the viscous fan then cuts in (its electonically controlled on the SC)

If I then switch the engine off and restart, everything is fine - the guage comes back to normal and the viscous fan cuts out.

This only ever happens on the first journey from stone cold - it is fine after that.

I changed the engine coolant sensor yesterday but it did exactly the same thing today. I just can't think what can be wrong - I'm going to change the thermostat next.

Has anybody got any idea what could be wrong ????? Stolen / Gone: 2006MY Supercharged LPG Autobiography - Zambezi Silver with Sand/Jet/Jet Oxford Leather.....

I've now changed the engine coolant sensor and the thermostat and yet the problem is still there......also, there are no fault codes stored in the ECU. The system has been bled properly about three times now - I'm sure there is no air trapped.

It's doing my head in - having searched this form, I noticed that two other Supercharged owners have reported the same fault - ngb13 and 44ark, I tried PM'ing them but my messages seem to be stuck in the Outbox so not sure if they have recieved them or not.

Interesting that 3 different Supercharged FFRR's seem to have experienced the same fault - but I cannot come up with the reason behind it  Stolen / Gone: 2006MY Supercharged LPG Autobiography - Zambezi Silver with Sand/Jet/Jet Oxford Leather.....

How is your vapouriser warmed?

It should have a constant supply of coolant to ensure it doesn't freeze up. Is it possible its not plumber in right and this when the thermostat opens they suck a lot of heat out of the water and thus the temp drops??

Does it make any difference if your running with your ac on or off?

Do you start from cold on LPG or let it auto switch over? If the latter is it not long after it switches over the issue occurs?

kingpleb wrote:

How is your vapouriser warmed?

It should have a constant supply of coolant to ensure it doesn't freeze up. Is it possible its not plumber in right and this when the thermostat opens they suck a lot of heat out of the water and thus the temp drops??

Does it make any difference if your running with your ac on or off?

Do you start from cold on LPG or let it auto switch over? If the latter is it not long after it switches over the issue occurs?

I would say that the way the LPG system gets its temperature reading is not correct and causing a drop across the circuit which is cleared with a restart. Possibly needs to use its own sensor and jot share the standard landrover unit instead??

I changed thermostat on my 4.2sc and now temperature gauge sits on the centre point after pointing to 10 o'clock for ages. The rubber seal on the thermostat was completely destroyed.

An easy job, but would recommend removing the housing and getting it in a vice to replace the spring loaded thermostat. I say this after pratting about with it in situ fighting all those prints. Piece of cake in the vice. 2014 5.0 Supercharged Autobiography & 2015 3.0SDV6 HSE Lux Discovery 4
2005 4.2 Supercharged Vogue SE & 2011 3.0SDV6 HSE Discovery 4
2002 4.4 Vogue
2000 4.6 Vogue
2011 Discovery 4 3.0 HSE
2015 Discovery 4 HSE Lux
2010 Freelander 2 TD4 HSE
2009 Freelander 2 TD4.e 2009
1992 Mercedes 300D
1986 Renault 2.1 Turbo D
1976 Morris Marina 1.8

The fan cutting in seems the strange one to me?? Surely it should go off as the temperature drops. Your problem sounds electrical to me not trapped air.

As the OP was 4 years ago I am guessing he no longer cares or has the car! Discovery 4 HSE
1998 110 TUM HS FFR Hard Top XD WOLF
1982 Series 3 Hard Top

*Gone:L462 D5 HSE LUX, L663 Defender 110 HSE, Discovery 3 HSE, 2014MY Range Rover Sport 5.0 Supercharged AB Dynamic; L405 Exec Vogue SE 4.4, 5.0 Supercharged Autobiography, Defender TDCi XS CSW, Defender TD5 HT, Vogue SE TDV8, Vogue TD6, RRSport SC 4.2V8, Classic 3.9 Vogue Auto, Land Rover Series 3 SWB

I wonder if he ever sorted it!!??

YES - I did  Stolen / Gone: 2006MY Supercharged LPG Autobiography - Zambezi Silver with Sand/Jet/Jet Oxford Leather.....

going to ask the next question, what was the problem?.

After replacing my thermostat, I have noticed a puddle under the car. I opened her up to check today to see if I had messed something up. Assuming that I had damaged something or that one of the many tools that I have lost in the engine compartment over the years had ended up damaging the radiator, but no sign of anything associated with my fumblings, but I did notice a leaking joint where two pipes are connected to the bottom of the thermostat housing by a plastic connector.

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