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fuel burning heater

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Hi , i have a 51 plate td4 es and noticed white smoke coming from in front of the n/s/f wheel, i have since found out it has a fuel burning heater to help speed up engine temperatures on cold mornings or if the coolant temp is below a certain temperature . I believe this is controlled by the ecu but was wondering if this can be altered to operate from a timer so that it can be set to switch on say 15 minutes before i am due to go out in a morning to warm up the cab and defrost the windows ?. has anybody done this or know if it can be done and if so who sells the timers .

regards

gary

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Chances are it'll be a Webasto or Eberspacher unit, it'll probably have a sticker on it telling you what it is. All the manuals & specs are available online, so that's not too hard. You may find the timer as an optional extra from LR, if not I'm sure you'd find one on eBay as loads of people sell the bits for them.

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Hi had the same thing thought omg what is that its a bit annoying as on every time you start up on it goes (is that normal) & if i move around drive to get another car out it still has to go through a shut down cycle it starts to get a bit smokey after 3 or 4 start stops plus it is burning fuel, can they be removed or shut down in any way, are they set by thermostat as mine starts up every time freebe is started i only use the freebie to take dog and me training shoooting 4-5 miles the most all farm tracks 10 mph (it does get muddy) i get to bunny warrens switch of & they get their own smoke screen plus whiiiiiiiiiiiiiiiirrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr for 30 secs any advice

cheers viz

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It's a Webasto heater, a version of the Thermotop C IIRC. Webasto offered a timer upgrade kit for the Freelander in the early days.

It's a long time since I fiddled with one, but the standard C can be switched on and off by grounding one wire. The standard timer also outputs a coded signal saying how long it's set to run for, but the C doesn't use/need it.

If you just want to disable it, one owner I know just pulled the multiplug out of the unit.

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hi i have freelander 54 reg td4 auto my wife drives it daily we have had it over a month it has been fine but in the last 2 weeks my wife reports that she has see smoke coming from wheel arch passenger side next time it was the grill passenger side low down and there is a electric buzz coming from behind passenger headlight and last about 30 seconds i think it has a fuel burning heater could it be that or could it be the brake sticking on cheers men

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If you do a search you will see this has been covered before, and the manuals are all at www.cameltrophyvehicles.com/downloads

Cheers

Blippie

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Hi all, another newbie here. As an aside to the discussion on the pre heater, I have just bought a `54 plate Td4 200 SE and so far, including the last couple of days at 0-1 deg. temps, I reckon my pre heater isn`t working. In fact it takes about 4 miles or so before any heat starts making itself felt.

Where should I look to A; make sure I`ve got one fitted, and B; look for a fault.

Could it be the temp sensor not working? Evidently they brought out a new one with different parameters, which was green. Where is this fitted?

Thanks in advance for any info, and it`s nice to be accepted as a Land Rover owner, even though the Freebie is looked down on by "real" Landie owners! ;)

Ray.

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Hi all, another newbie here. As an aside to the discussion on the pre heater, I have just bought a `54 plate Td4 200 SE and so far, including the last couple of days at 0-1 deg. temps, I reckon my pre heater isn`t working. In fact it takes about 4 miles or so before any heat starts making itself felt.

Where should I look to A; make sure I`ve got one fitted, and B; look for a fault.

Could it be the temp sensor not working? Evidently they brought out a new one with different parameters, which was green. Where is this fitted?

Thanks in advance for any info, and it`s nice to be accepted as a Land Rover owner, even though the Freebie is looked down on by "real" Landie owners! ;)

Ray.

As a follow up to my last post, I do have a fuel heater fitted, I can hear it working, especially after switching off. However, I don`t get any early heat in the car, just normal heat when the engine warms up, 3 - 4 miles.

When I was clearing snow from drive, I had car running and felt at the heater exhaust under bumber. Warm air was coming out, but no smoke/steam.

It appears to me the heater is coming on, but not putting any heat into the car, which is a waste of time, and fuel, if indeed it is burning any!

Any comments? How long should it take to get warm air into the car from the FBH?

Ray.

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Before you decide it's not making a difference, try unplugging it and see how long it takes to get heat into the car without it. It's a small unit and it's got a big cold block of metal to heat up, you can't expect miracles.

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Before you decide it's not making a difference, try unplugging it and see how long it takes to get heat into the car without it. It's a small unit and it's got a big cold block of metal to heat up, you can't expect miracles.

So it heats up the engine? I thought it somehow put heat into the car until the engine got up to temp.

This is the bit of info I wanted to answer my questions. Crikey, that TD4 IS cold blooded! Every other car I had was putting warm air in the car inside 1 mile! Mind you, I havn`t owned a diesel before. I just swapped my Jaguar XJ6 3.2 in for my landie about 3 weeks ago, just in time, and that thing had heat before I had done 1/2 mile. That "big cold block of metal" also kicks out a lot of heat.

About the only things I miss about the Landie is acceleration, especially when cold, (Er, should I go now? could you please confirm the last throttle position please!), and the above lack of heat. Otherwise I love it, and I got a newer car for the same price as an older Disco, which is what I was going to get.

Ray.

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Having just read the RAVE manual on this unit, it heats the coolant on its way to the heater matrix but only fires up when the air temp is below 5degC, looks from the wiring diagram like the 5deg switch (and it seems to be just a thermoswitch) could be replaced/bypassed. I'll be looking at doing this soon having just bought one and the boss showing off his telestart every time it gets a bit nippy :rolleyes:

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Having just read the RAVE manual on this unit, it heats the coolant on its way to the heater matrix but only fires up when the air temp is below 5degC, looks from the wiring diagram like the 5deg switch (and it seems to be just a thermoswitch) could be replaced/bypassed. I'll be looking at doing this soon having just bought one and the boss showing off his telestart every time it gets a bit nippy :rolleyes:

Won`t that mean it`s on all the time? could affect fuel consumption. Maybe it could be connected to a switch, to turn off when coolant warms through?

Ray.

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It would only be on all the time if you modified it to be on all the time :P

Given they burn about ~0.3 litres/hour flat out and 0.1 on low power I don't think it's going to be sucking your tank dry.

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Modern diesel engines like the TD4 are much more efficient than petrol (due to higher compression ratio - it's a thermodynamics thing) and they will not warm up unless they are under load. I have a TD4 auto and a drive to work of 7 miles of country roads consisting of about half a mile up a hill then flat for 5 miles then a 1.5 mile slow incline. It's only in the last mile that the engine gets properly warm and that's with the fuel burning heater going. It's not much different in the summer.

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I have just got back from a 200 mile motorway trip in cold weather with my TD4 auto and whenever I stopped anywhere (eg motorway services) the fuel burning heater was still going. Does this sound right? I am beginning to wonder if this engine is overcooled or if the thermostat (where is it?) is stuck open.

Does anyone remember in the old days how we used to blank off half the radiator in the winter? I am thinking of doing it again!

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I'd suggest a read of the Webasto manual - the heaters don't (can't) just shut off - there's a small fire going on inside, so they have to keep the fan running and wait for the fire to go out (fuel to burn off) and things to cool down (I.E. it's definitely not on fire any more) before they can shut down. The Eberspachers have a special mode for use in hazardous goods vehicles (petrol tankers etc.) where they can be forced to switch off instantly, but the intimation is it's not the best thing for the heater to be doing.

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well blow me down with a feather, my freelander has one of these heaters too ! :D I've had it for over a year, probably didn't know I had one because it doesn't seem to work lol,.

So I have the part number for a new sensor just in case i need one, I just need to check the fuse......any pointers to the correct fuse would be appreciated ;)

and then buy a controller for manual operations,

any further info out there gents?

thanks nathan

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Nathan - there's not much to it and all the wiring & fuses are in the RAVE manual, which is in the sticky at the top of the part numbers forum. To force it to start manually you can probably just change the sensor for a switch and extend the wires.

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Am I right in thinking that the heater runs constantly?

Like the above post states, I've driven 30+ miles and find the heater is still going when I park up. I would have thought once the engine has reached optimal temperature the heater should switch off?

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Since RTFM seems to be the hardest thing in the world...

Fuel Burning Heater (FBH) System (Where Fitted)

The FBH system only operates while the engine is running and the ambient temperature is less than 5 °C (41 °F).

With the engine running and the ambient temperature below 5 °C (41 °F), the air temperature sensor connects the alternator power supply to the ECU in the FBH unit. On receipt of the alternator power supply, the ECU starts the circulation pump and, depending on the input from the temperature sensor in the heat exchanger, enters either a standby or active mode of operation. If the heat exchanger casing temperature is 65 °C (149 °F) or above, the ECU

enters a standby mode of operation. If the heat exchanger casing temperature is below 65 °C (149 °F), the ECU enters an active mode of operation. In the standby mode, the ECU monitors the heat exchanger casing temperature and enters the active mode if it drops below 65 °C (149 °F). In the active mode, the ECU initiates a start sequence and then operates the system at full or part load combustion to provide the required heat input to the coolant.

Start Sequence

At the beginning of the start sequence the ECU energises the glow plug function of the glow plug/flame sensor, to preheat the combustion chamber and start the combustion air fan at slow speed. After approximately 30 seconds, the ECU energises the FBH fuel pump at the starting sequence speed. The fuel delivered by the FBH fuel pump evaporates in the combustion chamber, mixes with air from the combustion air fan and is ignited by the glow plug/flame sensor. The ECU then progressively increases the speed of the FBH fuel pump and the combustion air fan to either part or full load speed, as required by the system. Once full or part load speed is achieved, the ECU switches the glow plug/flame sensor from the glow plug function to the flame sensing function to monitor combustion. From the beginning of the start sequence to stable combustion takes approximately 90 seconds for a start to part load combustion and 150 seconds for a start to full load combustion

Coolant Temperature Control

When the ECU first enters the active mode, it initiates a start to full load combustion. Full load combustion continues until the heat exchanger casing temperature reaches 60 °C (140 °F), at this point the ECU decreases the speed of the FBH fuel pump and the combustion air fan to half speed, to produce part load combustion. The ECU maintains part load combustion while the heat exchanger casing temperature remains between 54 and 65 °C (129 °C and 149°F). If the heat exchanger casing temperature decreases to 54 °C (129 °F), the ECU switches the system to full load combustion again. If the heat exchanger casing temperature increases to 65 °C (149 °F), the ECU enters a control idle phase of operation.

On entering the control idle phase, the ECU immediately switches the FBH fuel pump off, to stop combustion, and starts a timer for the combustion air fan. After a 2 minute cool down period, the ECU switches the combustion air fan off and then remains in the control idle phase while the heat exchanger casing temperature remains above 59 °C (138°F). If the heat exchanger casing temperature decreases to 59 °C (138 °F) , within 15 minutes of the ECU entering the control idle phase, the ECU initiates a start to part load combustion. If more than 15 minutes elapse before the heat exchanger casing temperature decreases to 59 °C (138 °F), the ECU initiates a start to full load combustion.

In order to limit the build up of carbon deposits on the glow plug/flame sensor, the ECU also enters the control idle phase if the continuous part and/or full load combustion time exceeds 72 minutes. After the cool down period, if the heat exchanger casing is still in the temperature range that requires additional heat, the ECU initiates an immediate

restart to part or full load combustion as appropriate.

Shutdown

The FBH system is de-activated when the alternator power supply to the FBH unit is disconnected, either by the engine stopping or, if the ambient temperature increases to 5 °C (41 °F) or above, by the contacts in the air temperature sensor opening. If the system is active when the alternator power supply is disconnected, the ECU deenergises

the FBH fuel pump to stop combustion, but continues operation of the combustion air fan and the circulation pump to cool down the FBH unit. The cool down time depends on the combustion load at the time the alternator power input is disconnected.

Fuel Burning Heater (FBH) System (Diesel Models Only)

The FBH system is an auxiliary heating system that compensates for the relatively low coolant temperatures inherent

in the diesel engine. At low ambient temperatures, the FBH system heats the coolant supply to the heater assembly, and maintains it within the temperature range required for good in-car heating performance. Operation is fully automatic, with no intervention required by the driver.

The system consists of an ambient air temperature sensor, a FBH fuel pump and a FBH unit. Fuel for the FBH system is taken from the vehicle fuel tank, through a line attached to the fuel tank's fuel pump, and supplied via the FBH fuel pump to the FBH unit. The connection on the fuel tank's fuel pump incorporates a tube which extends down into the tank. In the FBH unit, the fuel delivered by the FBH fuel pump is burned and the resultant heat output is used to heat the coolant. An ECU integrated into the FBH unit controls the operation of the system at one of two heat output levels, 5kW at full load (i.e. maximum output) and 2.5 kW at part load.

The ambient air temperature sensor controls a power supply, from the alternator via the Engine Control Module (ECM) to the FBH unit. The sensor is installed on a bracket attached to the body behind the RH side of the front bumper valance. The sensor contains a switch that is closed at temperatures below 5 °C (41 °F) and open at temperatures of 5 °C (41 °F) and above.

FBH Fuel Pump

The FBH fuel pump regulates the fuel supply to the FBH unit. The FBH fuel pump is installed in a rubber mounting in a bracket attached inside the rear RH wheelarch. The pump is a self priming, solenoid operated plunger pump, with a fixed displacement of 0.063 cm3/Hz (0.002 US fl.oz/Hz). The ECU in the FBH unit outputs a pulse width modulated signal to control the operation of the pump. When the pump is de-energised, it provides a positive shut-off of the fuel supply to the FBH unit.

The FBH unit is installed behind the front bumper, in front of the LH wheelarch. It is connected in series with the coolant supply to the heater assembly. Two electrical connectors on the FBH unit connect it to the vehicle wiring.

Spring clamps secure the fuel supply line to a spigot on the FBH unit.

Circulation Pump

The circulation pump is installed at the coolant inlet to the FBH unit to assist the coolant flow through the FBH unit and the heater assembly. The pump runs continuously while the FBH unit is in standby or active operating modes.

While the FBH unit is inactive, coolant flow is reliant on the engine coolant pump.

Combustion Air Fan

The combustion air fan regulates the flow of air into the unit to support combustion of the fuel supplied by the FBH pump and to purge and cool the FBH unit. A canister type filter is included in the air inlet supply line to prevent particulates entering and contaminating the FBH unit.

Burner Housing

The burner housing contains the burner insert and also incorporates connections for the exhaust pipe, the coolant inlet from the circulation pump and the coolant outlet to the heater assembly. The exhaust pipe directs exhaust combustion gases to atmosphere through a pipe below the FBH unit.

The burner insert incorporates the fuel combustion chamber, an evaporator and a glow plug/flame sensor. Fuel from the FBH fuel pump is supplied to the evaporator, where it evaporates and enters the combustion chamber to mix with air from the combustion air fan. The glow plug/flame sensor provides the ignition source of the fuel:air mixture and,

once combustion is established, monitors the flame.

ECU/Heat Exchanger

The ECU controls and monitors operation of the FBH system. Ventilation of the ECU is provided by an internal flow of air from the combustion air fan. The heat exchanger transfers heat generated by combustion to the coolant. A sensor in the heat exchanger provides the ECU with an input of heat exchanger casing temperature, which the ECU

relates to coolant temperature and uses to control system operation. The temperature settings in the ECU are calibrated to compensate for the difference between coolant temperature and the heat exchanger casing temperature detected by the sensor. Typically, as the coolant temperature increases, the coolant will be approximately 7 °C (12.6°F) hotter than the temperature detected by the sensor; as the coolant temperature decreases, the coolant will be approximately 2 °C (3.6 °F) cooler than the temperature detected by the sensor

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Just done a 100 mile run down the M5 in my 04 reg TD4 auto in freezing conditions and noticed that the engine temperature (on the temp gauge) varied noticeably according to whether the engine was under load going up or down hill. Surely this is a sign of overcooling or a thermostat problem. Has anyone else noticed this sort of behaviour?

PS the fuel burning heater appears to be on continuously in this weather.

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