E91 Overheating Problem (it's not the water pump...)

D3Series · 10-18-2020, 01:10 PM

Good day fellow E9x owners

I sincerely hope you can help me, as it appears my local independent garage cannot...

I would like to give you all the complete recent history on what has happened, in the hopes that some genius amongst you can help me properly diagnose the fault my E91 320i SE 2008 [110,000 miles] is experiencing. Just over a month ago, whilst driving back from taking my son to University, I noticed that the car was doing better than usual MPG (it is usually around 32/33 MPG, but on this trip I was getting 37+ MPG, I have owned this car for two years and it has consistently done 32/33 MPG, sometimes a teeny bit better on motorways...)

So after arriving back home, feeling pretty chuffed that such an old girl was doing decent miles to the gallon, I had to pop out again to the shops.

About 2 miles from home and the yellow overheating warning light came on (the thermometer in water symbol), about 5 seconds after that yellow light came on, it went red and the car immediately went into limp mode. 5 seconds after that, the red light went off and limp mode disapeared and the car was driving like normal again. This was very confusing but I remained at a slow speed...

About a minute later, it did exactly the same thing again. Yellow, then red/limp mode for about 3 to 5 seconds, then cleared and the car was fine again. Then about a minnute later, it would repeat again.

Luckily, my local garage was just around the corner, so I nursed the car over to them.

The car was with them for exactly 4 weeks, whilst they tried to diagnose the fault. They said the water pump was working and they didn't know what to do. I don't have a BMW dealer in my area (the nearest one is about 80 miles away). After much back and forth, the garage owner decided that it would be best to replace the coolant temp. sensor first, to see how that goes and failing that, the water pump and thermostat, as these were high failure parts, and considering the mileage, everything pointed to those..

So I had the coolant temp. sensor replaced, but alas, the fault remained. So myself and the garage agreed to replace the water pump and thermostat.

£614.00 later, I have a new water pump and temp. sensor fitted, but bizarrely, they didn't fit a new thermostat!? I only discovered this yesterday after looking at the invoice for the work done.

The garage said they did not know where to turn next, as the car is still doing the exact same fault/behaviour.

Could this be the thermostat or is this something truly bizarre? I'm going to phone them tomorrow and find out why they didn't fit the thermostat. They knew it was best practice to replace both at the same time. They even told me both had been ordered!

So when I picked the car up yesterday, the owner of the garage said very sorry, but we cannot fix this and don't know what else to try.

So I'm stuck. I drove the car home and it went into limp mode at least 5 times on the short 2.5 miles back home.

The garage assured me that car is not overheating, that it is an electronic fault of some kind. I was also informed when picking the car up that the engine management light had come on and after reading the code, the mechanic said that the oil temperature sensor has also failed. I've since noticed that the car will no longer give me an oil level reading either. I get 'INACTIVE' when trying to read the oil level.

What do I do? Could this be the thermostat alone? I have searched forums and online videos and it seems these electronnic thermostats can fail but usually fail stuck open, so I shouldn't be getting this type of weird error.

Apolgies for the wall of text, but short of scrapping the car, I don't know where to turn.

Thank you all.

Tunafish · 10-18-2020, 01:22 PM

Tough situation you in there and on the forum without being able to diagnostic car its going to a lot of hail marrys.. The water pump and oil has the BSD line in common and one could effect the other through this. To get to the bottom of this you will need a code scanner that for bmw's, do you know the codes that are popping up?

D3Series · 10-18-2020, 01:33 PM

Thank you for your reply, Tunafish - much appreciated.

I don't have the codes but I'm going to ask the garage for all of these tomorrow and will post here.

So the oil temp. sensor could be responsible for this glitch/error overall? That's very interesting.

Thank you again.

F31B48 · 10-18-2020, 01:55 PM

Does your 320i have the N46 engine or N43? The reason i ask is just to clarify first, as the N46 has a mechanical water pump, and N43 is an electric water pump.

Tunafish · 10-18-2020, 02:43 PM

Yeah sorry didnt see the model but BSD might not apply to you..

gbalthrop · 10-18-2020, 02:50 PM

Quote:

Originally Posted by D3Series

... E91 320i SE 2008... About 2 miles from home and the yellow overheating warning light came on (the thermometer in water symbol), about 5 seconds after that yellow light came on, it went red and the car immediately went into limp mode. 5 seconds after that, the red light went off and limp mode disappeared and the car was driving like normal again. This was very confusing but I remained at a slow speed...About a minute later, it did exactly the same thing again. Yellow, then red/limp mode for about 3 to 5 seconds, then cleared and the car was fine again. Then about a minute later, it would repeat again.
So I had the coolant temp. sensor replaced, but alas, the fault remained. So myself and the garage agreed to replace the water pump and thermostat.
£614.00 later, I have a new water pump and temp. sensor fitted, but bizarrely, they didn't fit a new thermostat!? I only discovered this yesterday after looking at the invoice for the work done. The garage said they did not know where to turn next, as the car is still doing the exact same fault/behaviour.
So when I picked the car up yesterday, the owner of the garage said very sorry, but we cannot fix this and don't know what else to try. So I'm stuck. I drove the car home and it went into limp mode at least 5 times on the short 2.5 miles back home. The garage assured me that car is not overheating, that it is an electronic fault of some kind.

I was also informed when picking the car up that the engine management light had come on and after reading the code, the mechanic said that the oil temperature sensor has also failed. I've since noticed that the car will no longer give me an oil level reading either. I get 'INACTIVE' when trying to read the oil level...

(A) If you can scan the invoice(s) that itemize parts fitted & labor, and attach a copy as jpg or pdf to your next post, that would be helpful. (B) Also, please provide the Last-7 Characters of your VIN so those of us with ISTA can look up the correct wiring diagrams for your vehicle. The VIN will probably indicate, but to make SURE we are looking at correct system for you vehicle, (C) please indicate if you have N43 or N46 Engine. BOTH are 4 cylinder, naturally aspirated engines, but the N43 is direct injection.

Your description of the Red Over-Temp warning light that goes away on its own in seconds suggests that the ACTUAL engine temperature is NOT excessive, but rather, the SIGNAL received by the DME (Engine Control Module) from the ECTS (Engine Coolant Temp Sensor) is out of range. Temp Sensors are Thermistors which change resistance (Ohms) inversely proportional to the Coolant Temp, as the Temperature Rises, the resistance Drops. If there is a "Short-circuit" in the Temp Sensor wiring or connector, the DME will get a signal whose voltage is too HIGH based upon too low resistance, and cause the warning light or limp/shutdown. If you had ACTUAL engine temp high enough to cause limp/shutdown & Red Temp Warning Light, the overheat condition would NOT dissipate in 5 seconds.

Also, the SES light and Oil Sensor Fault Code & "Inactive" readout when trying to check level (same sensor measures Oil LEVEL & Oil Temperature), suggests you have a BSD bus wiring or connector fault. The BSD Bus is the signal line for the Oil Sensor, Coolant Pump, Alternator, & IBS (Intelligent Battery Sensor). So rather than immediately have concern for replacement of the OZS (Oil Condition Sensor), I would look for a common issue for BOTH the Engine Temp Warning Light and the OZS code.

Your 2008 BMW may be in very good ACTUAL condition, with ONLY some electrical Gremlins. First thing I would recommend is to let the car idle for several minutes while you monitor the ACTUAL engine temperature at the ECTS Housing using an Infrared Thermometer, and as you or a helper ALSO monitor the ECTS Signal (Temp) as received by the DME, using either a basic scan tool or "Hidden Menu 7.00" which allows you to view that parameter on the Instrument Cluster.
http://e90.wikifoundry.com/page/BC+hidden+menus

FIRST thing needed to be determined is if Coolant Temp at the Sensor (ECTS) Housing is ACTUALLY excessive, or if you JUST have an ERRONEOUS signal fault. If your shop did NOT do that

Also, I would ask shop what BRAND water pump was installed, and what BRAND pump was removed, AND if they still have the pump removed. Try to have the shop explain what tests led them to "assure you that the car is NOT overheating". I would HOPE that is correct, but we need to be SURE of that fact BEFORE we chase an electrical fault. The fact that they changed the Coolant Pump, only to have the SAME symptoms remain, suggests they did NOT properly test FIRST.

YOU should be aware that there is BMW Diagnostic Software offered on MULTIPLE Web Sites, FREE. If you have a Windows OS Laptop, your only expense is a $45 US "K+DCAN" Cable that connects the USB port of the laptop to the OBD II Socket of your car. THEN with help of the Forum YOU can view and save Screens that show data (Fault Codes, Parameter such as Temp Signals, etc.) which you can save ScreenPrints of and post here for ANALysis by the "Self-appointed" experts who hangout here.

If that's too much trouble, at least find a local shop that has that Software and knows how to use it. Based upon posts by UK residents, it sounds like INPA/ISTA - using shops are somewhat rare in UK?

Unless you have totally sworn off tools and any hope of DIY, you might consider getting a DMM (Digital Multimeter) and Infrared Thermometer, or even an entry level Scan Tool, such as these examples from Amazon UK:
https://www.amazon.co.uk/Silverline-...049439&sr=8-47
https://www.amazon.co.uk/Thermometer...%2C239&sr=8-28
https://www.amazon.co.uk/Autel-AutoL...049908&sr=8-19

The Scan Tool linked will NOT connect to modules OTHER than the DME, and is in NO WAY as good as INPA/ISTA. It is a good tool however for reading basic Engine Module Codes in most any motor vehicle built this millennium, and easy entry-level tool that will give you what you need for your current issues.

Please let us know what tools you have available & what you find,
George

D3Series · 10-19-2020, 02:59 AM

George, what a reply, thank you very much. I truly appreciate you taking the time to send over all of that info. I feel a lot better about the situation now.

The last 7 characters of the VIN are: A153336

I believe the engine is the N43 (it is certainly an electronic water pump).

The garage have said it is a Pierburg water pump that was fitted.

I will request the further info from the garage today (but I'm not hopeful and rather irritated with them, I feel that because they couldn't properly diagnose it, they just wanted to get rid of me).

I will purchase those additional tools you have kindly linked to and will get back here as soon as I have the necessary info.

Thank you very much again, George and to all who replied.

Darin

gbalthrop · 10-19-2020, 11:00 AM

Quote:

Originally Posted by D3Series

... The last 7 characters of the VIN are: A153336. I believe the engine is the N43 (it is certainly an electronic water pump). [Yes, ISTA indicates that VIN has N43 Engine & MT. The garage have said it is a Pierburg water pump that was fitted. [That should be brand installed @ Factory, so should NOT have caused BSD bus issue].
I will request the further info from the garage today (but I'm not hopeful and rather irritated with them, I feel that because they couldn't properly diagnose it, they just wanted to get rid of me). [It's "Human Nature" to "Avoid" troublesome cases (Back-of-the-desk syndrome), which I and most folks I know engage in, at least on occasion -- so try to get info from them, or share what YOU may learn from the forum to see if you can help them help you]...Darin

Hi Darin,

I don't know what your prior experience level has been with automotive systems, mechanical or electrical, but you seem to have interest and be a quick study. If you want to see what Resources/ References are available online to properly maintain your E91, see the attached pdf: "E9x References". Unfortunately, after nearly three years of successful operation on the Web, "newtis.info" has closed, so we have to use ISTA to get equivalent information. See pdf for information about BMW Standard Tools, E89 Datens & Rheingold/ISTA, along with the K+DCAN Cable to connect computer to vehicle.

If you have the time & interest, you can go a long way toward "DIY" (DIAGNOSING ISSUES Yourself ;-) by downloading Rheingold/ISTA to your Windows computer (whether Laptop or Desktop) and spending a few hours getting familiar with HOW to Search the program for "Documents" such as Repair Procedures, Wiring Diagrams, Installation Locations, Connector Views, etc. for YOUR specific vehicle.

ALL the stuff a Tech needs to know or reference to correctly diagnose & repair a fault. The Download is FREE, and you do NOT need to be connected to the vehicle to research a vehicle's systems. The Documents (SSP wiring diagrams) attached to the next post (so as NOT to ruin the margins here), are examples of what is found in ISTA, and obviously I am NOT connected to your vehicle.

What is attached to next post:
1) Engine Cooling System SSP: showing Coolant pump, Thermostat & ECTS.
2) Fuse F38 SSP: F38 Power Supply to Thermostat Control & OZS (Oil Condition Sensor).
3) Oil Supply SSP: F38 Power supply, ground and Signal to DME @ X6254 OZS Connector.
4) Fuse Chart, 2 pages, from Bentley Manual pdf, 2008 & later models.

So forget what we said earlier about BSD bus, as the OZS is NOT on that bus system on your 2008 320i. I would test the OZS "Inactive" issue separately from the "Overheat" (whether ACTUAL or Bogus Signal), EXCEPT for F38 check.

Note that fuse F38 powers BOTH the OZS and the MAP Thermostat. The thermostat functions as a Normal mechanical thermostat, EXCEPT it has an electrical heater in the wax bulb which can signal to thermostat to open more or at lower coolant temp if engine demands suggest. So although the engine were NOT getting too warm, if there were a fault in that "heater" supply/ function, that fault would be noted by the DME & perhaps warning lights, etc. could occur. Obviously if there is an F38 failure, the OZS is NOT powered and can't function.

So check F38 FIRST, and then let us know what you find & what questions you may have.

George

gbalthrop · 10-19-2020, 11:02 AM

Attached, related to 2008 320i N43:

1) Engine Cooling System SSP: showing Coolant pump, Thermostat & ECTS.
2) Fuse F38 SSP: F38 Power Supply to Thermostat Control & OZS (Oil Condition Sensor).
3) Oil Supply SSP: F38 Power supply, ground and Signal to DME @ X6254 OZS Connector.
4) Fuse Chart, 2 pages, from Bentley Manual pdf, 2008 & later models.

George

D3Series · 10-21-2020, 01:52 PM

George, you have restored my faith in humanity. Seriously, I can't express properly here on this thread how grateful I am for your time and imparting your extensive and incredible expertise - it is truly appreciated. You are a true gent.

I am not mechanically minded at all. I have a fairly low IQ and am not very practical either. I'm quite useless with cars and other such technical machines. Actually, overall, I'm just useless.

I won't be able to diagnose this. It is way beyond me, so I have decided to scrap the car. It's old (like me) and tired (like me too). I have given up.

Thank you again, George. And what an asset you are to this forum and I suppose anyone else around you that would need expert advice on these automobiles. I have no doubt that to anyone else, your advice would have had them back on the road. Regretfully for me, it's a lost cause - but I did try, in my limited capacity and understanding, I promise.

Take good care and all the best.

Darin

vazcm · 05-18-2022, 05:55 AM

I'm having the same issue. My engine is N46. The yellow overheating warning light came on, about 5 seconds after that yellow light came on, it went red and the car immediately went into limp mode. 5 seconds after that, the red light went off and limp mode disapeared and the car was driving like normal again.

My oil sensor is also INACTIVE.

Any updates on this?

Quote:

Originally Posted by D3Series

Good day fellow E9x owners

I sincerely hope you can help me, as it appears my local independent garage cannot...

I would like to give you all the complete recent history on what has happened, in the hopes that some genius amongst you can help me properly diagnose the fault my E91 320i SE 2008 [110,000 miles] is experiencing. Just over a month ago, whilst driving back from taking my son to University, I noticed that the car was doing better than usual MPG (it is usually around 32/33 MPG, but on this trip I was getting 37+ MPG, I have owned this car for two years and it has consistently done 32/33 MPG, sometimes a teeny bit better on motorways...)

So after arriving back home, feeling pretty chuffed that such an old girl was doing decent miles to the gallon, I had to pop out again to the shops.

About 2 miles from home and the yellow overheating warning light came on (the thermometer in water symbol), about 5 seconds after that yellow light came on, it went red and the car immediately went into limp mode. 5 seconds after that, the red light went off and limp mode disapeared and the car was driving like normal again. This was very confusing but I remained at a slow speed...

About a minute later, it did exactly the same thing again. Yellow, then red/limp mode for about 3 to 5 seconds, then cleared and the car was fine again. Then about a minnute later, it would repeat again.

Luckily, my local garage was just around the corner, so I nursed the car over to them.

The car was with them for exactly 4 weeks, whilst they tried to diagnose the fault. They said the water pump was working and they didn't know what to do. I don't have a BMW dealer in my area (the nearest one is about 80 miles away). After much back and forth, the garage owner decided that it would be best to replace the coolant temp. sensor first, to see how that goes and failing that, the water pump and thermostat, as these were high failure parts, and considering the mileage, everything pointed to those..

So I had the coolant temp. sensor replaced, but alas, the fault remained. So myself and the garage agreed to replace the water pump and thermostat.

£614.00 later, I have a new water pump and temp. sensor fitted, but bizarrely, they didn't fit a new thermostat!? I only discovered this yesterday after looking at the invoice for the work done.

The garage said they did not know where to turn next, as the car is still doing the exact same fault/behaviour.

Could this be the thermostat or is this something truly bizarre? I'm going to phone them tomorrow and find out why they didn't fit the thermostat. They knew it was best practice to replace both at the same time. They even told me both had been ordered!

So when I picked the car up yesterday, the owner of the garage said very sorry, but we cannot fix this and don't know what else to try.

So I'm stuck. I drove the car home and it went into limp mode at least 5 times on the short 2.5 miles back home.

The garage assured me that car is not overheating, that it is an electronic fault of some kind. I was also informed when picking the car up that the engine management light had come on and after reading the code, the mechanic said that the oil temperature sensor has also failed. I've since noticed that the car will no longer give me an oil level reading either. I get 'INACTIVE' when trying to read the oil level.

What do I do? Could this be the thermostat alone? I have searched forums and online videos and it seems these electronnic thermostats can fail but usually fail stuck open, so I shouldn't be getting this type of weird error.

Apolgies for the wall of text, but short of scrapping the car, I don't know where to turn.

Thank you all.

gbalthrop · 05-18-2022, 11:08 AM

Quote:

Originally Posted by vazcm

I'm having the same issue. My engine is N46. The yellow overheating warning light came on, about 5 seconds after that yellow light came on, it went red and the car immediately went into limp mode. 5 seconds after that, the red light went off and limp mode disapeared and the car was driving like normal again. My oil sensor is also INACTIVE.

Welcome to the Forum!

NOT familiar with the N46 Engine. If you will provide the LAST-7 Characters of your VIN, we can suggest things to check.

Please indicate if you have ANY of the following:
Scan Tool (Brand & Model)
Diagnostic Software (INPA/ISTA)
Multimeter
Infrared Thermometer

Has that Warning Light issue happened on MORE than the ONE occasion you describe?
How long has the engine been operating before the Warning Lights appear?

George

Saywhen · 12-12-2022, 02:47 AM

I have a problem: Just got an overheating light on my dash. less than 5k miles ago I had a service engine soon light with code p0128 saying my thermostat wasnt working properly. Replaced it and engine light went away and everything was solid. New coolant, no leaks whatsoever (left splash guard off and checked every day to make sure no leaks). After I did the thermostat and coolant I did the flush thing to burp all the air out, took like 10 mins but again everything was kosher. No idea why its overheating now, with no service engine light, only the over heating light.
when I got overheating light on dash I pulled over and stopped and let it cool off, had absolutely no coolant leaking out of reservoir. Any ideas?

10-18-2020, 01:10 PM	#1
D3Series New Member 0 Rep 5 Posts Drives: BMW E91 320i SE Join Date: Oct 2020 Location: Wales iTrader: (0)	E91 Overheating Problem (it's not the water pump...) Good day fellow E9x owners I sincerely hope you can help me, as it appears my local independent garage cannot... I would like to give you all the complete recent history on what has happened, in the hopes that some genius amongst you can help me properly diagnose the fault my E91 320i SE 2008 [110,000 miles] is experiencing. Just over a month ago, whilst driving back from taking my son to University, I noticed that the car was doing better than usual MPG (it is usually around 32/33 MPG, but on this trip I was getting 37+ MPG, I have owned this car for two years and it has consistently done 32/33 MPG, sometimes a teeny bit better on motorways...) So after arriving back home, feeling pretty chuffed that such an old girl was doing decent miles to the gallon, I had to pop out again to the shops. About 2 miles from home and the yellow overheating warning light came on (the thermometer in water symbol), about 5 seconds after that yellow light came on, it went red and the car immediately went into limp mode. 5 seconds after that, the red light went off and limp mode disapeared and the car was driving like normal again. This was very confusing but I remained at a slow speed... About a minute later, it did exactly the same thing again. Yellow, then red/limp mode for about 3 to 5 seconds, then cleared and the car was fine again. Then about a minnute later, it would repeat again. Luckily, my local garage was just around the corner, so I nursed the car over to them. The car was with them for exactly 4 weeks, whilst they tried to diagnose the fault. They said the water pump was working and they didn't know what to do. I don't have a BMW dealer in my area (the nearest one is about 80 miles away). After much back and forth, the garage owner decided that it would be best to replace the coolant temp. sensor first, to see how that goes and failing that, the water pump and thermostat, as these were high failure parts, and considering the mileage, everything pointed to those.. So I had the coolant temp. sensor replaced, but alas, the fault remained. So myself and the garage agreed to replace the water pump and thermostat. £614.00 later, I have a new water pump and temp. sensor fitted, but bizarrely, they didn't fit a new thermostat!? I only discovered this yesterday after looking at the invoice for the work done. The garage said they did not know where to turn next, as the car is still doing the exact same fault/behaviour. Could this be the thermostat or is this something truly bizarre? I'm going to phone them tomorrow and find out why they didn't fit the thermostat. They knew it was best practice to replace both at the same time. They even told me both had been ordered! So when I picked the car up yesterday, the owner of the garage said very sorry, but we cannot fix this and don't know what else to try. So I'm stuck. I drove the car home and it went into limp mode at least 5 times on the short 2.5 miles back home. The garage assured me that car is not overheating, that it is an electronic fault of some kind. I was also informed when picking the car up that the engine management light had come on and after reading the code, the mechanic said that the oil temperature sensor has also failed. I've since noticed that the car will no longer give me an oil level reading either. I get 'INACTIVE' when trying to read the oil level. What do I do? Could this be the thermostat alone? I have searched forums and online videos and it seems these electronnic thermostats can fail but usually fail stuck open, so I shouldn't be getting this type of weird error. Apolgies for the wall of text, but short of scrapping the car, I don't know where to turn. Thank you all.
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10-18-2020, 01:22 PM	#2
Tunafish Banned 262 Rep 818 Posts Drives: BMW 335i N55 Join Date: Dec 2019 Location: Home iTrader: (0)	Tough situation you in there and on the forum without being able to diagnostic car its going to a lot of hail marrys.. The water pump and oil has the BSD line in common and one could effect the other through this. To get to the bottom of this you will need a code scanner that for bmw's, do you know the codes that are popping up?
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10-18-2020, 01:33 PM	#3
D3Series New Member 0 Rep 5 Posts Drives: BMW E91 320i SE Join Date: Oct 2020 Location: Wales iTrader: (0)	Thank you for your reply, Tunafish - much appreciated. I don't have the codes but I'm going to ask the garage for all of these tomorrow and will post here. So the oil temp. sensor could be responsible for this glitch/error overall? That's very interesting. Thank you again.
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10-18-2020, 01:55 PM	#4
F31B48 Captain 278 Rep 657 Posts Drives: BMW G21 E61 LCI Join Date: Feb 2019 Location: Australia iTrader: (0)	Does your 320i have the N46 engine or N43? The reason i ask is just to clarify first, as the N46 has a mechanical water pump, and N43 is an electric water pump. Last edited by F31B48; 10-18-2020 at 03:48 PM..
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10-18-2020, 02:43 PM	#5
Tunafish Banned 262 Rep 818 Posts Drives: BMW 335i N55 Join Date: Dec 2019 Location: Home iTrader: (0)	Yeah sorry didnt see the model but BSD might not apply to you..
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10-19-2020, 02:59 AM	#7
D3Series New Member 0 Rep 5 Posts Drives: BMW E91 320i SE Join Date: Oct 2020 Location: Wales iTrader: (0)	George, what a reply, thank you very much. I truly appreciate you taking the time to send over all of that info. I feel a lot better about the situation now. The last 7 characters of the VIN are: A153336 I believe the engine is the N43 (it is certainly an electronic water pump). The garage have said it is a Pierburg water pump that was fitted. I will request the further info from the garage today (but I'm not hopeful and rather irritated with them, I feel that because they couldn't properly diagnose it, they just wanted to get rid of me). I will purchase those additional tools you have kindly linked to and will get back here as soon as I have the necessary info. Thank you very much again, George and to all who replied. Darin
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10-19-2020, 11:02 AM	#9
gbalthrop Brigadier General 2689 Rep 4,031 Posts Drives: 2007 328xi E91 Join Date: May 2017 Location: Fairfax Co, VA iTrader: (0)	Attached, related to 2008 320i N43: 1) Engine Cooling System SSP: showing Coolant pump, Thermostat & ECTS. 2) Fuse F38 SSP: F38 Power Supply to Thermostat Control & OZS (Oil Condition Sensor). 3) Oil Supply SSP: F38 Power supply, ground and Signal to DME @ X6254 OZS Connector. 4) Fuse Chart, 2 pages, from Bentley Manual pdf, 2008 & later models. George Attached Images
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10-21-2020, 01:52 PM	#10
D3Series New Member 0 Rep 5 Posts Drives: BMW E91 320i SE Join Date: Oct 2020 Location: Wales iTrader: (0)	George, you have restored my faith in humanity. Seriously, I can't express properly here on this thread how grateful I am for your time and imparting your extensive and incredible expertise - it is truly appreciated. You are a true gent. I am not mechanically minded at all. I have a fairly low IQ and am not very practical either. I'm quite useless with cars and other such technical machines. Actually, overall, I'm just useless. I won't be able to diagnose this. It is way beyond me, so I have decided to scrap the car. It's old (like me) and tired (like me too). I have given up. Thank you again, George. And what an asset you are to this forum and I suppose anyone else around you that would need expert advice on these automobiles. I have no doubt that to anyone else, your advice would have had them back on the road. Regretfully for me, it's a lost cause - but I did try, in my limited capacity and understanding, I promise. Take good care and all the best. Darin
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12-12-2022, 02:47 AM	#13
Saywhen Registered 0 Rep 2 Posts Drives: bmw 335i Join Date: Dec 2022 Location: US iTrader: (0)	I have a problem: Just got an overheating light on my dash. less than 5k miles ago I had a service engine soon light with code p0128 saying my thermostat wasnt working properly. Replaced it and engine light went away and everything was solid. New coolant, no leaks whatsoever (left splash guard off and checked every day to make sure no leaks). After I did the thermostat and coolant I did the flush thing to burp all the air out, took like 10 mins but again everything was kosher. No idea why its overheating now, with no service engine light, only the over heating light. when I got overheating light on dash I pulled over and stopped and let it cool off, had absolutely no coolant leaking out of reservoir. Any ideas?
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