Thanks, that explanation was nice and clear. Just an additional thought for anyone thinking of trying the same test... The thermostat for the N43 engine on my wife's e92 320i is either supposed to open at 97°C or 102°C, depending on the part number. So not all of them should open when submerged in boiling water. (From a quick search for the part number, I think the example here is meant to open at 97°C, so it does seem to be faulty.)

By far this is the best demo of how these thing works . I never heard of it until code po597 came on my 2012 chevy cruze. I clear the code with no drive ability issue but i know that it will come back on after driving at higher speed like 60-80 mph for highway speed. I did the resistance and it was 35 ohms and the spec on it is 15-16 ohms

Nice little video thanks !!!! I'm stumped, ice cold inlet and output pipe to Thermostat, car boils up, closed off system. I replaced it twice and then checked again.... My 2x new OEM spec Mahle did not open in hot water pan at 100c but didn't also have 12v power to it now know with MAP based Thermostats. 'learning' ... The circuit must not be working guess as on or off the car the Mahle stays closed. That is both the new Mahle thermo's. I took this 12 reg corsa in for crankcase oil leak and came out unable to stop overheat and had a Water pump, thermo, and header tank. Most puzzling, no head gasket issue, drives as should..... Indeed I have tested 20 kilometre driven with housing thermo pipe wide open, thermo in housing totally removed. Once 2x new Mahle Thermo on car boils up in 2k again as radiator loop closed off, thermo closed. I'm stuck to understand why this MAP thermo won't open on my car and on an OHMS test in the house.... these Thermo are not faulty, the car isn't operating them . Can you think where I have gone wrong, temp coolant sensor on order...... Many thanks

Thank You, I have had two failed ones both failed closed, the second brand new OEM out of the box, that turned out to be broken electrical connections inside the thermostat, awaiting replacement from BMW. Not sure if this is the right move, with the cost of new OEM parts, might be better to buy two cheap after market units, worst mistake I made was throwing away the original one because of age but was working normally, you live and learn.

Best explanation!!!! If you have a BMW N55 335i and you drive crazy like me and engine temp gets like 120c, replace its thermostat with the Ford f150 thermostat and ENJOY driving fast and crazy or maybe drifting at all time!!! In middle East we call it “change it from electric to mechanic” 🤜🏻🤛🏻

Thanks Gerard for this great video. I'm trying to diagnose an over heating issue on my N43 engine'd E88 -when the heaters are turned off the engine will overheat quickly and the bottom hose rad remains ice cold, your video demonstrates these thermostats fail close so I'll definitely be replacing that ASAP.

thanks for your contribution

The benefits to reducing emissions and improving fuel economy are grossly exaggerated. This thermostat does not do anything different than a conventional one during engine warm up where the engine is running rich. On the other end of the spectrum this system merely adds another layer of completely unnecessary CEL events and codes, costing big bucks to the car owner for diagnosis, parts, and repairs.

Emissions, emissions, emissions! The reason for most of our failing components. Unfortunately, the manufacturers don't seem to come up with long term components that are able to cope with the strict requirements of emission control.

Well explained Gerard like always.🔧

Can this ever stuck open? I am trying to figure out why the coolant temp on my F30 316i (N13 engine) takes ages to get to 80C and never past that.

Hi friend, Two positions for the electric thermostat? If 12V to open and if not 12V to cloed. Right?

Great Video. Thanks🙏

how many volts should the connection for the thermostat have when it is cold?

Well explained Gerard, Thankyou:):)

nice work & thanx

How to make thermostat quickly,any idea?

Hi I have a Z4e85 2.0i that mounts a map twrmostat with 105° opening in fuel economy the range is always between 107° and 109° in the norm I would like to lower this range in fuel economy by making it remap from the ecu from a computer can you force it to open with a lower temperature?

My car is a 528xi and it has this thermostat here. When driving, the temperature drops to 76-80 degrees and the engine runs cold, is there any way to increase the temperature a little?

Mini has the temp sensor on the housings

Engineers at BMW "lets screw and overcomplicate the simple things"

Can I convert my Yaris to a BMW. I need to control the coolant temp especially at speeds above 200 km per hour. Now that's just down your regular country boreen never mind the motorway.

Whats the point in having a thermostat opening earlier to get better emission figures before the engine has got up to operating temperature? Surly this defeats the purpose of the thermostat? Not having the engine up to operating temperature as soon as possible would cause premature engine wear thus shortening the life of the engine. Where is environmental benefit in wearing out the engine faster?

But from my point of view I don't think an electrical thermostat will close with the water temperature because it's already using a 12v supply to close meaning if the solenoid is damaged it won't open with the water temperature as the way you tried to demonstrate to us or maybe I'm wrong?

👍

This stupid high temp thermostat is killing the engine