E90 320i PFL Coolant Temperature ? Ways to reduce ?

BMW-GK

Well-Known Member
Dear Pro Bros,

Can anyone advise our E90 coolant temperature range ?

I am getting 105 - 110 degree C everyday ... via OBD2.

Is it possible to mod to the thermostat to reduce the temp ??

Thank you...
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

use a lighter engine oil. Castrol 0w-30 only ( german castrol) - reduce by 5
Coolant and water mixture instead of 50/50, use 75/25 water/coolant mixture - reduce by 1 or 2

Please take note that as we are in Singapore, we don't need coolant for it's anti-freeze properties, we need coolant for it's anti rust properties. Water actually is better coolant than coolant itself.
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

I remembered there are thermostats for the water pump / radiator that kicks in at a lower temp ....... saw the guys install it at workshops ..... but that was quite some time back.
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

Why reduce thermostat temp? Sorry but i noob.
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

Red_Bean_Bun;1076489 said:
I remembered there are thermostats for the water pump / radiator that kicks in at a lower temp ....... saw the guys install it at workshops ..... but that was quite some time back.

If I am not wrong... I also saw a post here... some bros here mod his thermostat with picture some more... BUT could not find the POST liao..

Anyone can advise ?? OR any low temp thermostat to change ?
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

alvinado;1076485 said:
use a lighter engine oil. Castrol 0w-30 only ( german castrol) - reduce by 5
Coolant and water mixture instead of 50/50, use 75/25 water/coolant mixture - reduce by 1 or 2

Please take note that as we are in Singapore, we don't need coolant for it's anti-freeze properties, we need coolant for it's anti rust properties. Water actually is better coolant than coolant itself.

We also need coolant to increase the boiling point of the coolant-water mixture, so that it doesn't start boiling everytime it reaches 100 deg C :)
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

It won't boil. The pressure cap is rated at 14 bar. Water has a boiling temp of 400 degree Celsius at 14 bar.
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

That could be the one for the oil cooler if it was recent ................................

I was referring to the radiator / water pump thermostat since stock NA engines got no oil coolers ......

BMW-GK;1076494 said:
If I am not wrong... I also saw a post here... some bros here mod his thermostat with picture some more... BUT could not find the POST liao..

Anyone can advise ?? OR any low temp thermostat to change ?
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

alvinado;1076496 said:
It won't boil. The pressure cap is rated at 14 bar. Water has a boiling temp of 400 degree Celsius at 14 bar.

It should be 14 psi. Normal atmospheric pressure is 14.69psi, giving water a normal boiling point of water of 100C.
With a 14psi radiator cap, the pressure in the system increases to double the atmospheric pressure, giving water a boiling point of around 119C.
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

I am getting mostly 108-113'C max, after watching it for some time.

Guess our e90 engines run hot.

Was contemplating change coolant to engine ice, or motul wetter which claim to reduce coolant temp by 5'C

BMW-GK;1076476 said:
Dear Pro Bros,

Can anyone advise our E90 coolant temperature range ?

I am getting 105 - 110 degree C everyday ... via OBD2.

Is it possible to mod to the thermostat to reduce the temp ??

Thank you...
 
Last edited by a moderator:
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

canuck78;1076595 said:
I am getting mostly 108-113'C max, after watching it for some time.

Guess our e90 engines run hot.

Was contemplating change coolant to engine ice, or motul wetter which claim to reduce coolant temp by 5'C

Bro .. thought of changing to engine ice tooo...

But if our thermostat operate at 105 degree C ... which means the thermostat only open up at 105 for the coolant to go to the radiator... won't it be the same ?

If our thermostat are ECU or temperature control that I think changing to any coolant also no point... we still got the same temperature...

Bros ... correct me if I am wrong... I am here to learn ... :eek:
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

Started with 115c on my engine when I got from my dealer - n54 engine.

- flushed the radiator and filled it with distilled water and coolant (50/50 ratio). Temp dropped slightly - moved a wee bit towards the 110c mark on my temp gauge.
- Bled the system (use bleed screw) and then added redline water wetter. It actually made it worst and went back to 115c
- Bled a bunch out (used the bleeding procedure with engine off) and re-filled with more distilled water. Gauge needle moved back closer to the 110c mark.
- Changed to GC. Gauge needle moved right on top of the 110c mark.
- Changed my oil cooler thermostat and gauge needle moved between the 100c and 110c mark.

Had engine ice on my previous Z4 (NA engine) - not much of a diff back then in terms of temp and it was costly .......

IMHO - I think the engine ice, water wetter stuff is over rated .....


BMW-GK;1076610 said:
Bro .. thought of changing to engine ice tooo...

But if our thermostat operate at 105 degree C ... which means the thermostat only open up at 105 for the coolant to go to the radiator... won't it be the same ?

If our thermostat are ECU or temperature control that I think changing to any coolant also no point... we still got the same temperature...

Bros ... correct me if I am wrong... I am here to learn ... :eek:
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

BMW-GK;1076610 said:
Bro .. thought of changing to engine ice tooo...

But if our thermostat operate at 105 degree C ... which means the thermostat only open up at 105 for the coolant to go to the radiator... won't it be the same ?

If our thermostat are ECU or temperature control that I think changing to any coolant also no point... we still got the same temperature...

Bros ... correct me if I am wrong... I am here to learn ... :eek:

I have the same thought as you bro. I think we should not be so quick to jump to conclusion that our engines are running unusually hot because these "high" readings may be due to where the temp sensor is located in the coolant circuit. My Jap ride coolant temp is consistently around 89-92C and if it get past 100 sure something is wrong (as I've experienced). I find it hard to believe that there is really a 20C difference in normal coolant operating temp between these engines, more likely that our bimmer sensor is tapping into the high temp side of the fluid circuit. This is my conjecture, welcome any correction.
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

I got this from the web... About N46 Engine which can be found in most new E46 or E90 or N87 etcs - BMWClubMalaysia.com Forums

Engine cooling
The opening and closing of the map thermostat (N46 only) is controlled by a characteristic map. This regulating operation can be split into 3 operating ranges:
· Map thermostat closed:
The coolant only flows through the engine and the coolant circuit is closed.
· Map thermostat open:
The entire coolant volume flows through the radiator. This results in maximum use of the available cooling output.
· Control range of the map thermostat:
A proportion of the coolant flows through the radiator. The map thermostat maintains a constant coolant temperature within the control range at the engine inlet.
In this operating range, the coolant temperature can now be selectively controlled with the assistance of the map thermostat. This means that a high coolant temperature can be set in the part-load range of the engine. High operating temperatures in the part-load range result in improved combustion. This in turn leads to reduced consumption and exhaust emission.
During full load operation, certain disadvantages are associated with higher operating temperatures (retarding of ignition due to knock).
A lower coolant temperature is therefore specifically set during full load operation with the assistance of the map thermostat.
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

Also found this at the same web page above ...

Map thermostat
The opening and closing of the map thermostat (N46 only) is controlled by a characteristic map.
The map thermostat ensures that within its control range a constant coolant temperature is maintained at the engine inlet.
For driving conditions with low loads, the map thermostat sets a high coolant temperature (efficient consumption). For full loads or higher engine speeds, the coolant temperature is reduced to protect the components.
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

IS our e90 320i N46 engine thermostat ECU / electronically controlled ?

If it is... can we re-program or tune it ?
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

BMW-GK;1076687 said:
Also found this at the same web page above ...

Map thermostat
The opening and closing of the map thermostat (N46 only) is controlled by a characteristic map.
The map thermostat ensures that within its control range a constant coolant temperature is maintained at the engine inlet.
For driving conditions with low loads, the map thermostat sets a high coolant temperature (efficient consumption). For full loads or higher engine speeds, the coolant temperature is reduced to protect the components.

That prob explains why my coolant is usually running high, coz my loads are low and no where to chiong :shakehea:
 
Re: E90 320i PFL Coolant Temperature ? Ways to reduce ?

Now you got me thinking ........ will be testing this out on a 320i N46........

BMW-GK;1076688 said:
IS our e90 320i N46 engine thermostat ECU / electronically controlled ?

If it is... can we re-program or tune it ?
 

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