If you don't have a set I would highly recommend getting one. Makes the job a lot easier.I have ordered a new viscous coupling (£40).
I noticed there are several 'versions' available; some say they are for 'hot climates' and some also say they are for 'no electric fan', even though realoem only gives one part number.
I can only presume the bimetallic strip on some move at different temperatures to others??
I have ordered a 'generic' one with the correct part number, so let's hope it makes a difference.
You're not measuring this by your own addon temp sensor mounted way down low by the radiator drain plug? I assume you needed a temp sensor for the temp gauge of your rebody ferrari style dash having lost access to the stock Z3 gauge. But down there you're just measuring the temp of water leaving the bottom of the radiator which is not the actual block temperarure.. . .
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I ran it for an hour and a half and it got to 75c ish. The viscous clutch is making at around 65c and it creeps up to 75 ish . . . . . .
The measurement is via my code reader, but I don't know which sensor it is taking the info from. There are two 'original' sensors; one in the middle of the radiator and one under the intake manifold. My 'gauge' sensor has not replaced anything, it is screwed into the drain plug.You're not measuring this by your own addon temp sensor mounted way down low by the radiator drain plug? I assume you needed a temp sensor for the temp gauge of your rebody ferrari style dash having lost access to the stock Z3 gauge. But down there you're just measuring the temp of water leaving the bottom of the radiator which is not the actual block temperarure.
OK but all of my trials are at tickover which doesn't make sense. And the viscous clutch is purely mechanical, operated via temperature, so is independent of whatever the car is doing (apart from spindle speed which is directly driven by the crank).The stock BMW M54 thermostat, often considered the "tropical" variant, opens at around 97°C (207°F), but the M54 engine also incorporates an engine management system that can open the thermostat earlier to a computer-controlled temperature for increased power. This is a map thermostat that can be commanded open by the DME to reduce coolant temperature when high power is requested.
Understanding the thermostat's operation:
Map Thermostat: The M54 engine uses an electronically controlled thermostat, sometimes referred to as a "map thermostat" or "electronic thermostat".
DME Control: The Engine Control Unit (DME) can command the thermostat to open at different temperatures depending on the engine's demand.
Coolant Temperature Management: When the DME determines maximum power is requested, it can signal the thermostat to open at a lower temperature than its standard 97°C, resulting in a cooler coolant temperature.
Normal operating temperature:
While the thermostat's primary opening point is around 97°C, the engine's normal operating temperature typically fluctuates between 90-95°C.
Temperatures can temporarily rise to around 100-105°C, especially in hot weather or heavy traffic.
Key takeaway:
The BMW M54 thermostat doesn't have a single fixed opening temperature; it can open earlier than its stock 97°C setting at the command of the engine's computer to help the engine achieve maximum efficiency and power when needed.
Yes, indeed. Although this will be no help, and others who obviously know my car better than I do will tell you I'm wrong, I've gone the last few years without a fan at all and, as far as I'm aware, it still works. I didn't notice any mention of actually taking one of these new-fangled IR temp gauges to various parts of the engine and seeing what is happening. The temp never going above 75 is not good, and points towards a defective thermostat, easily checked by taking it out, warming it up in a pan of water, (best done when no fussy people are watching) and seeing when it opens.but surely something is not right here?
AgreedThe temp never going above 75 is not good, and points towards a defective thermostat,
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Also correct but, TBH, If I went to the trouble of undoing the thermostat housing and taking out a 25 year old thermostat then I'd put a new one in anyway.. . .
. . . easily checked by taking it out, warming it up in a pan of water, (best done when no fussy people are watching) and seeing when it opens.
Something like this will do
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You wouldn't get a job in a dealership (or any service sector) these days. That attitude is not conducive to big profits. I have this argument almost every day with the idiots that work for me!I was taught to find out what was wrong first, not to just fit a bunch of parts in the hope that something would cure the fault.
It's clean and quite shiny actually. It was just a bit of grime on the metallic strip. I cleaned that and it made no difference whatsoever.If your viscous coupling is old, black and ugly, it's finished. The black is the oil that gradually seeped out and attracted road grime. They're 50 quid new - if in any doubt, buy a new one.