[F30NFifty5]

I was attempting to swap my coolant temp sensor that supposed to attach to the radiator hose on my "n52" 07 328xi sedan when i realized that it isn't there. or maybe i just don't see/feel it... but I swear it's not there. made me wonder if the fan was replaced with maybe a N51 fan if at all even possible..

The radiator fan I have now is the one where the oil cooler connects to the bottom... and the power connector is on the right side of the fan(if you were facing the engine bay)

anybody replace theirs and can point me in the right direction?

[gbalthrop]

Originally Posted by F30NFifty5

I was attempting to swap my coolant temp sensor that supposed to attach to the radiator hose on my "n52" 07 328xi sedan when i realized that it isn't there. or maybe i just don't see/feel it... but I swear it's not there...

Is your A/C Compressor functioning OK and is the A/C cooling OK?
Have you Scanned the DME (Engine Control Module) for Fault Codes?
WHAT Codes are read, if any?
If you start the engine "cold" with IHKA/Climate Control switched OFF, does Fan turn for a few seconds & stop?
Does your Fan run at full speed even when engine is cold and A/C OFF?
Does your Engine Temp warning light ever come on, either Yellow or Red?
Do you have any of the following, and if so, describe Make/Model: Scan Tool, Diagnostic Software, Digital Multimeter, Meter that can read "Duty Cycle" or PWM (Pulse Width Modulated) signal?

If you have an N52 as opposed to N51 SULEV, then you do NOT have an ROTS (Radiator Outlet Temp Sensor on the Lower Radiator Hose, and the E-Fan Speed is generally controlled by the DME based upon (1) ECTS (Engine Coolant Temp Sensor) signal as received by the DME, (2) Vehicle Speed, and (3) Refrigerant Pressure Sensor signal as received by the JBE Module and IHKA Module (The Refrigerant Pressure Parameter can be read using INPA connected to EITHER of those Modules). If the E-Fan goes to Max Speed any time the A/C is switched ON, regardless of cooling or vehicle speed, that suggests a bad Refrigerant Pressure Switch, connector or wiring.

The Fan Speed-regulating electronics is built into the Fan Unit & NOT replaceable as a separate unit. Once again, INPA can test for proper fan response to speed signal input, and you can control E-Fan Speed using "Activation" of E-Fan, where you select speed, 15%, 50% or 90% of max speed, and observe Actual Fan Speed in response to that "Over-ride" of DME Control, ALL on your computer screen, NO Guesswork. There have been a number of reported cases where the fan speed control electronics have failed in such a way that the Fan ALWAYS ran at full speed, simply OFF/ON, without any speed regulation. Based upon what you have described thus far, the E-fan Electronics would by my "most likely candidate".

Perhaps time to get INPA: $45 for a BimmerGeeks K+DCAN Cable, several hours to download (FREE) & install BMW Standard Tools which includes INPA, BMW Factory-level Diagnostic Software, and we can help you connect & read the correct Screen so you do NOT waste time/$$$ throwing parts or paying someone else to Diagnose the issue.

If you had INPA, you could quickly read the Refrigerant Pressure Sensor "Parameter" or the Signal (Pressure readout in "bar" value) from that sensor. Any decent Scan Tool can read the ECTS Parameter, OR you can use "Hidden Menu 7.00" to display the value as received by the DME on the Instrument Cluster as you drive. If you are concerned about the ECTS or its Connector or wiring, you can check the signal as you drive. The signal as received by the DME (and displayed on Hidden Menu 7.00 & Scan Tool Engine Temp Parameter) is what you need to be concerned about. If that value is where it SHOULD be (~95C - 105C) then Fan should NOT be running full speed with car MOVING.

You can check the ECT Sensor itself (independent of connector & wiring) by measuring resistance across the two spades/pins of the Sensor. That Sensor is a "Thermistor", meaning its resistance varies inversely with temperature. The resistance measured across the pins after removing connector should be in the range of 2500 Ohms at 20C and 250 Ohms at 90C.

Proper Diagnostics using INPA is about a LOT MORE than just reading Fault Codes. That's ONLY the starting point. INPA allows you to (1) Read Live Data from INPUTS from Sensors to the Module to which they connect (such as ECTS Temp Value, or Refrigerant Presure Sensor Value, OR Actual Fan Speed; and to (2) Activate a Motor (solenoid, relay or other electrical device) such as E-Fan, Coolant Pump, Fuel Pump, by "Over-riding" Module control of that Motor WHILE you observe the speed or other response to that "Over-riding Control", allowing you to test the OUTPUT circuit from the Module to the Motor/Device, and the function of the Motor/Device itself.

Please let us know answers to questions above, and we can suggest "next steps".

George