You can see from my pic above, the central part just pulls out. Ron B. VK2OTC
2004 L322 V8 Auto
2007 Yamaha XJR1300
Previous: 1983, 1986 RRC; 1995, 1996 P38A; 1995 Disco1; 1984 V8 County 110; Series IIA

I believe ohuntsman is talking about the cast part that holds the heating element. In order for his to be in a different orientation the heating element would need to be redesigned and or the functioning guts would need to be redesigned which just wouldn't be cost effective. That leaves us with the new modified thermostat made wrong or installation error.

That central heating element part goes up inside the thermostat. The wiring on mine had corroded away so it just pulled out.

Since the arrival of the cold spell over the last few weeks, my FF 4.4 V8 takes an age to get up to temp, like in excess of an hour. I guess this is a sign my thermostat is failing. I would like to change it for a lower temp one, I don't want to do any cutting of the housing. Thinking of a straight swop. Does the BMW 740d thermostat work without any mods? it looks like a straight swop, is this correct?

Thanks

If you go back to my post on the 2nd of Jan last year I ordered one of the BMW 88 deg ones. http://www.fullfatrr.com/forum/topic39362-30.html

you can see it here on amazon but i never fitted it so couldn't say if it is a straight swap but it certainly looks like it.
It isn't cheap though..

https://www.amazon.co.uk/dp/B00HAH8AU8/ref..._ttl_sol_0

Have a shop around, i think this is the same one

https://www.ebay.co.uk/itm/Engine-Coolant-...SwSlBYxngF

i still have my one if you want to make me an offer

In my search to find a cheaper option I found the 740d is the identical housing with the lower temp and heating element port capped off. Just wasn't a cheaper option.

Thanks for the explanation, I’ve found one for a reasonable price
https://www.motor-doctor.co.uk/products/70...at-coolant

One thing though, can the 740d still accept the heater sensor, I need a new sensor as mine has broke.

Cheers

If you use the 740d thermostat you have removed where and why you have that connector. With this change most just move the connector out of the way. It will trigger a code but most of the time it doesn't trigger a service engine soon light. Mine did/does trigger a stuck thermostat code that does need to be cleared. I installed a resistor as per instructions from the guys that make the modification but sill it happens from time to time.

Thanks my sensor has been broken for awhile, so no code is generated. In reality what does the sensor do. In the long run is this in anyway detrimental to the system?

If you are talking about the plug on the thermostat it’s not a sensor but a heater.
It’s designed to heat up when the engine is under heavy load to open the thermostat earlier than the 105 degrees it would open at normally

Thanks for the explanation

holidaychicken wrote:

If you are talking about the plug on the thermostat it’s not a sensor but a heater.
It’s designed to heat up when the engine is under heavy load to open the thermostat earlier than the 105 degrees it would open at normally

I get an electric thermostat open circuit fault logged but it doesn’t effect anything and doesn’t cause the EML light to come on, I just waterproofed the disconnected cable and tucked it out the way.

If you connect a resistor across the supply to the heater element what happens if the car decides it wants the heater to activate and puts full power down the wires rather than just detecting a resistance?

I know it’s recommended to do it by the site selling the lower stats but don’t really understand how it wouldn’t give a problem if the full amount of current is sent to it unless it’s a decent sized resistor I guess ?
Reading back over your post, 10 ohms / 100W is a fair size, is that what is recommended ?

If the engine ECU just sends a brief low voltage pulse to check if the thermostat is present , is it possible that a large resistor just presents an effective open circuit ? does the heater element have a resistance of 10 ohms ?
Trying to remember my school days ..

60 x 16 mm body size for the resistor so it is no light weight. By theory the ECU finds the closed circuit provided by the resistor and thinks all is well. The open circuit would be the problem.

That's not a resistor thats a telegraph pole