70deg thermostat for 2.5si

4

4play

Member
 UK
Saw a YouTube video where it was suggested that a lower temp thermostat helps the 2.5 run cooler and that they are less likely to have problems with hardened valve stem seals and various other issues.
Can anyone confirm this
Is the thermostat separate from the housing that's replaced or can they be ordered with various temp valves?
 
That sounds like 100%, gold plated, 32 carat bollox. I'd love to know what channel that is so that I can avoid watching it.

* the thermostat controls water temperature. Valve seals will be more affected by oil temperature which is sort of connected to water but not a hard correlation

* Not running at proper temps will affect fuel consumption and running in general (if only mildly)

* are you starting with a factory fresh engine or brand new valve seals? If not, why worry now? It's an engine that's full of parts that are the thick end of 20 years old - they've not going to be rejuvenated by running a bit cooler.

I can't say I've heard of stem seals being a problem with the N52, they do drink oil but that's a characteristic of alusil lined engines.
 
smorris_12 said:
That sounds like 100%, gold plated, 32 carat bollox. I'd love to know what channel that is so that I can avoid watching it.

* the thermostat controls water temperature. Valve seals will be more affected by oil temperature which is sort of connected to water but not a hard correlation

* Not running at proper temps will affect fuel consumption and running in general (if only mildly)

* are you starting with a factory fresh engine or brand new valve seals? If not, why worry now? It's an engine that's full of parts that are the thick end of 20 years old - they've not going to be rejuvenated by running a bit cooler.

I can't say I've heard of stem seals being a problem with the N52, they do drink oil but that's a characteristic of alusil lined engines.
Click to expand...


Content for contents sake?
 
Definitely misinformation. If you go into the secret menu and have a look, the car runs the electric water pump at a variable speed to target ~100C highway cruising coolant temperature (hotter = more fuel efficiency) and brings the temperature down immediately if you floor it (colder = more power). 70C is too low, and installing that means your oil is being cooled by the radiator via the heater exchanger when it isn't even up to temperature yet, which would worsen cold start lubrication for longer.
 
Rsipad said:
Definitely misinformation. If you go into the secret menu and have a look, the car runs the electric water pump at a variable speed to target ~100C highway cruising coolant temperature (hotter = more fuel efficiency) and brings the temperature down immediately if you floor it (colder = more power). 70C is too low, and installing that means your oil is being cooled by the radiator via the heater exchanger when it isn't even up to temperature yet, which would worsen cold start lubrication for longer.
Click to expand...
Would also not remove moisture and fuel from the oil which will degrade the lubrication properties and clog the PCV system!
 
Ah, a BMW Doctor video. I very nearly put that my the original post as a guess. I've seen a very few of his videos and never made it more than a few minutes in as they're long-winded and he's never demonstrated any accurate technical knowledge.

I think we can safely ignore the entire idea.
 
It's not just thermostats, this weekend I've seen 2 YouTube videos about tyre pressures. Showing us to put the pressure up to 10% less than the max pressure shown on the sidewall. 😱
 
MikeyH said:
It's not just thermostats, this weekend I've seen 2 YouTube videos about tyre pressures. Showing us to put the pressure up to 10% less than the max pressure shown on the sidewall. 😱
Click to expand...
Gee I wonder what that does. I think you should try it and let us know how that goes, Mikey :unsure::LOL:
 
So we come full circle once again.
All the good info and real world experience is on this forum.
FB and YouTube have to be taken with a whole mine-full of salt!
 
Page 54 of this BMW pdf adds more information on the cooling system

This means that four different temperature ranges can be implemented:
• 112°C ECO mode (economy)
• 105°C Normal mode
• 95°C High mode
• 80°C High + mapped thermostat mode
The coolant control sets a higher cylinder head temperature (112°C) if the engine control
unit determines ECO mode based on the current operating conditions.
The engine is operated with relatively low fuel consumption in this temperature range as
the internal friction is reduced.
An increase in temperature therefore favors lower fuel consumption in the low load range.
In HIGH and mapped thermostat mode, the driver wishes to utilize the optimum power
development of the engine. The cylinder head temperature is therefore reduced to 80° C.
This results in improved volumetric efficiency, thus increasing the engine torque. The
engine control unit can therefore set a certain operating mode adapted to the respective
driving situation. Consequently, it is possible to influence fuel consumption and power
output by means of the cooling system.
Click to expand...
 
You must log in or register to reply here.
Back
Top Bottom