Failing IAT sensor

kulxio · 08-02-2019, 08:59 AM

Hi!

I've been running the 3.5 bar sensor the last 6 months or so, which has been working great until a few weeks ago.
Sometimes it stops working which results in limp mode and a max reading in MHD.
Somedays it's working fine, while somedays it's not working at all. It seems to mostly fail when the engine is getting warm.
The boost reading is always fine even when the IAT reading is failing.

I checked all the cables and cleaned the sensor, with no result.

I could of course order a new sensor, but was wondering if anyone has experienced this?

type-dRew · 08-02-2019, 11:04 AM

Not sure what you want to get out of this.

You have a bum sensor. Unless you have screwed with the wiring or have a DME issue, the fix is replacing the sensor.

kulxio · 08-02-2019, 02:09 PM

Quote:

Originally Posted by type-dRew

Not sure what you want to get out of this.

You have a bum sensor. Unless you have screwed with the wiring or have a DME issue, the fix is replacing the sensor.

Yeah I know the sensor is probably toast, I was more interested in if this is a common issue (the 3.5 bar sensor failing) since I've never heard about it.
Or maybe if the sensor is sensitive to heat or whatever.

I'm using the supplied adapter harness so it would be difficult to screw up.

Jeff@TopGearSolutions · 08-02-2019, 03:07 PM

Normally they are not sensitive whilst installed but if you tug on the wire or bang them around they can easily break. Possibly with high mileage, it could otherwise fail.

dpaul · 08-03-2019, 12:50 PM

According to Terry Burger (Burger Motor Sports) there are a lot of counterfeit N20 sensors floating around. If you didn't get yours from a dealer or authorized OEM source, perhaps you got a fake.

kulxio · 08-03-2019, 05:47 PM

Quote:

Originally Posted by dpaul

According to Terry Burger (Burger Motor Sports) there are a lot of counterfeit N20 sensors floating around. If you didn't get yours from a dealer or authorized OEM source, perhaps you got a fake.

Do you know if there is anyway to tell them apart? I bought it from a dealer I thrust, but it would be interesting to double check.

I noticed that the sensor is only failing when I'm coming to a stop and stays for a while. Then I have to drive for a few minutes before it starts working again.
It won't fail as long as I don't stop.

dpaul · 08-04-2019, 06:33 AM

I don't know the way to tell them apart - some fakes are apparently pretty good (although I once bought an N20 sensor that was supposed to be OEM and had the correct part number but didn't even fit the hole in the manifold correctly). Bosch OEM spark plugs are being counterfeited too (or so I'm informed by usually reliable internet posters). My operating assumption is that anything I get from vendors like FCP Euro, ECS tuning or Tischler (getbmwparts.com) is OK. Certainly if you bought it from a BMW dealer, I'd assume it was legitimate.

08-02-2019, 08:59 AM	#1
kulxio Enlisted Member 8 Rep 30 Posts Drives: E92 335i Join Date: Mar 2018 Location: Europe iTrader: (0)	Failing IAT sensor Hi! I've been running the 3.5 bar sensor the last 6 months or so, which has been working great until a few weeks ago. Sometimes it stops working which results in limp mode and a max reading in MHD. Somedays it's working fine, while somedays it's not working at all. It seems to mostly fail when the engine is getting warm. The boost reading is always fine even when the IAT reading is failing. I checked all the cables and cleaned the sensor, with no result. I could of course order a new sensor, but was wondering if anyone has experienced this?
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08-02-2019, 11:04 AM	#2
type-dRew Major 649 Rep 1,245 Posts Drives: 2009 335i xDrive Join Date: Feb 2019 Location: Newport MI iTrader: (0)	Not sure what you want to get out of this. You have a bum sensor. Unless you have screwed with the wiring or have a DME issue, the fix is replacing the sensor. __________________ 2009 335i xDrive AT / 177k+ miles PSP 750ic / Fuel-It! Stage 1 / BMS CP / Sutphin Tuning / RFP E50 11.61 @ 117.5 New setup; Covid 19Ts on RFP 93 + ARM inlets, dp, VTT cp and PSP outlets
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08-02-2019, 03:07 PM	#4
Jeff@TopGearSolutions 3482 Rep 79,210 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	Normally they are not sensitive whilst installed but if you tug on the wire or bang them around they can easily break. Possibly with high mileage, it could otherwise fail.
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08-03-2019, 12:50 PM	#5
dpaul Lieutenant Colonel 662 Rep 1,893 Posts Drives: 2009 E90 335xi, 2011 E93 M3 Join Date: Dec 2012 Location: Boston iTrader: (3)	According to Terry Burger (Burger Motor Sports) there are a lot of counterfeit N20 sensors floating around. If you didn't get yours from a dealer or authorized OEM source, perhaps you got a fake.
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08-04-2019, 06:33 AM	#7
dpaul Lieutenant Colonel 662 Rep 1,893 Posts Drives: 2009 E90 335xi, 2011 E93 M3 Join Date: Dec 2012 Location: Boston iTrader: (3)	I don't know the way to tell them apart - some fakes are apparently pretty good (although I once bought an N20 sensor that was supposed to be OEM and had the correct part number but didn't even fit the hole in the manifold correctly). Bosch OEM spark plugs are being counterfeited too (or so I'm informed by usually reliable internet posters). My operating assumption is that anything I get from vendors like FCP Euro, ECS tuning or Tischler (getbmwparts.com) is OK. Certainly if you bought it from a BMW dealer, I'd assume it was legitimate.
	Appreciate 0 Quote