[jeepzj96]

Good morning all,

I was driving in this morning (I have about an hour drive) and right from the start the car wasn't runing like it always does. When I stepped on the gas to hop on the hwy it was gutless and too a while to get up to the normal cruising speed. I left it like that for a while and then I noticed that my temp guage was not increasing and I still had cold air blowing out of my vents - which is unusual as I always have hot within like 10 min of driving.

I did the secret menu to pull up the temps and bam....looks like my coolant temp is -128°C (impossible), and I have no indication of oil temp - which is weird as well.

Now, it has been cold here in Ontario (around -10°C or so), and the car was parked outside, but this has never been an issue in the past.

Any ideas on how and what to investigate?? Much appreciate any help.



Thanks,

-Hubert

[n3985]

Erratic sensor readings and cold weather would suggest your battery is old and on its way out. Get your battery tested and look at label how old it is.

Long time to reach operating temp and no heat would suggest bad thermostat.

[jeepzj96]

Originally Posted by n3985

Erratic sensor readings and cold weather would suggest your battery is old and on its way out. Get your battery tested and look at label how old it is.

Long time to reach operating temp and no heat would suggest bad thermostat.

I thought so too, but I actually just replaced the battery lasty week, registered it and it scanned good...so I don't think it would be related?

-H

[BrandBMW]

First thing is to check or replace is the coolant temp sensor since you have an outrageous reading. The heater valve that allows hot coolant to the hvac heater core may not open if the coolant temp is not showing the coolant is warm enough. Keeping the heater valve closed until the engine coolant is warm enough improves cold engine running and emissions.

A bad thermostat would still show the lowest ambient temp outside or it getting too hot due to it not opening.

[jeepzj96]

Originally Posted by BrandBMW

First thing is to check or replace is the coolant temp sensor since you have an outrageous reading. The heater valve that allows hot coolant to the hvac heater core may not open if the coolant temp is not showing the coolant is warm enough. Keeping the heater valve closed until the engine coolant is warm enough improves cold engine running and emissions.

A bad thermostat would still show the lowest ambient temp outside or it getting too hot due to it not opening.

Question...where do I find this sensor? Is this the one on the radiator hose?

So to build on this...any idea why I'm not seeing a readout for oil temp? I would have assumed these are all different sensors.. no?


I'm woried that this could lead to overheating the engine possibly since the coolant might not cool the engine thinking that it's already cool.

thanks
-H

[BrandBMW]

Hmm, I thought it was on the block. RealOEM describes it as both coolant/oil temp sensor and perhaps the oil and coolant readings are affected by this one sensor. Maybe check the connection first. Looks like a good place to start.

p/n 13627580635
#16 in the parts list and diagram
https://www.realoem.com/bmw/enUS/sho...47#13627580635

[jeepzj96]

Originally Posted by BrandBMW

Hmm, I thought it was on the block. RealOEM describes it as both coolant/oil temp sensor and perhaps the oil and coolant readings are affected by this one sensor. Maybe check the connection first. Looks like a good place to start.

p/n 13627580635
#16 in the parts list and diagram
https://www.realoem.com/bmw/enUS/sho...47#13627580635

Thanks, love that site. I did a search and I think you were looking at the wrong year. I have a 2013, so this is the part # I found -> 13621433076
It looks to be located right on side of the head, right by the oil filter housing.

I took the connector off and it was full of oil...so I'm suspecting that this could possible be a bad sensor? I'm thinking there should be no oil in the electrical connector? Makes sense.. right?



Did a scan with ISTA and this is the main screen of errors as well as the engin temp error...I'm thinking an engine temp of - 1000°C is def not correct.


..
..



What else should I be looking at?


-H

[BrandBMW]

Awesome! Yup, you said it. There shouldn't be any oil in the connector. Do you know why there is oil there?....such as the oil filter housing gasket?

Might still work if you can clean the connector (both male & female) ends. If it doesn't, maybe you will need a new one if it shorted.

[jeepzj96]

Originally Posted by BrandBMW

Awesome! Yup, you said it. There shouldn't be any oil in the connector. Do you know why there is oil there?....such as the oil filter housing gasket?

Might still work if you can clean the connector (both male & female) ends. If it doesn't, maybe you will need a new one if it shorted.

Now that I pulled it out and am looking at it, it looks more like a oil pressure sensor and not temp to be honest. I looked up the #'s on it SENSATA V759253280-01 and Google is showing me results for an oil pressure sensor.. damn..

https://partsauto360.com/oil-pressur...ta-133590.html

Here is where I found it..



and the sensor (oil pressure I think)



And I did find the coolant/oil temp sensor as well just a tad below the pressure sensor :

..
So now the million dollar question...how can I test the temp sensor if it's good or faulty? Any ideas?


And also, should I replace the oil pressure sensor at the same time since it had oil in it?


I know..I know.. the engine is filthy..I never got around to washing it prior to winter, was busy building my 1,200 sq ft garage..

-H

[BrandBMW]

Yes, that would make sense if it is connected to the oil filter housing area. You will know if it is an oil pressure sensor if it has a tiny hole at the end. The temp sensor should be in the coolant flow, which you show in the last pic.

I don't have the resistance figures, but if you cleaned the connections and the sensor is still operating faulty, then probably a good idea to replace it. No need to replace the oil pressure sensor if you don't get a warning.