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Repair Summary
The following article gives detailed instructions on replacing the cylinder head temperature sensor in a BMW with the N20 2.0 liter 4 cylinder engine. The N20 engine was used in many BMW models including the 1,2,3,4,5,X and Z vehicles. Even though we have used a 2014 BMW 320i to perform this repair, this article can be applied to any vehicle with the N20 engine with minor modifications.
See all vehicles this article applies to
E84 X1 Series X1 16i
F20 1 Series 125i
F20N 1 Series 125i
F21 1 Series 125i
F21N 1 Series 125i
F22 2 Series 228iX
F22 2 Series 228i
F23 2 Series 228iX
F23 2 Series 228i
F30 3 Series 328i
F30 3 Series 328iX
F30N 3 Series 328i
F31 3 Series 328iX
F31 3 Series 328i
F31N 3 Series 328iX
F34 3 Series 328iX
F34 3 Series 328i
F32 4 Series 428iX
F32 4 Series 428i
F33 4 Series 428iX
F33 4 Series 428i
F36 4 Series 428iX
F36 4 Series 428i
F07N 5 Series 528i
F10 5 Series 528i
F10 5 Series 528iX
F10N 5 Series 528iX
F10N 5 Series 528i
F11 5 Series 528iX
F11 5 Series 528i
F11N 5 Series 528iX
F11N 5 Series 528i
E84 X1 Series X1 28iX
E84 X1 Series X1 20i
E84 X1 Series X1 28i
E84 X1 Series X1 20iX
F25 X3 Series X3 18i
F25 X3 Series X3 20i
F25 X3 Series X3 20iX
F25 X3 Series X3 28iX
F25 X3 Series X3 28i
F26 X4 Series X4 28iX
F26 X4 Series X4 20iX
F15 X5 Series X5 28iX
F15 X5 Series X5 40eX
F16 X6 Series X6 28iX
E89 Z4 Series Z4 28i
E89 Z4 Series Z4 20i
E89 Z4 Series Z4 18i
F22 2 Series 220i
F23 2 Series 220i
F30 3 Series 320iX
F30 3 Series 320i
F30N 3 Series 320iX
F30N 3 Series 320i
F31 3 Series 320i
F31 3 Series 320iX
F34 3 Series 320i
F34 3 Series 320iX
F32 4 Series 420iX
F32 4 Series 420i
F33 4 Series 420i
F10 5 Series 520i
F10N 5 Series 520i
F11 5 Series 520i
F11N 5 Series 520i
F35 3 Series 328LiX
F35 3 Series 328Li
F35N 3 Series 328Li
F35N 3 Series 328LiX
F18 5 Series 525Li
F18N 5 Series 528LiX
F18N 5 Series 530Le
F18N 5 Series 525Li
F18N 5 Series 528Li
E84 X1 Series X1 18i
F35 3 Series 320Li
F35N 3 Series 320Li
F18 5 Series 520Li
F18N 5 Series 520Li
A BMW N20 cylinder head temperature sensor failure is a known cause of engine power shutdown and the vehicle entering "limp mode".
There have been reports slowly filtering in from BMW owners of vehicles with the N20 2.0L engine entering "limp mode" while driving for no apparent reason. It usually happens after the engine warms up and while idling at a traffic light or a stop sign. Sometimes a "check engine" light may be displayed...but sometimes it may not.
The 2014 320i that we used for this article started shutting down approximately five minutes into driving with no check engine light and the engine temperature gauge operating correctly. When we turned the engine off and restarted, the vehicle would return to normal operation for a few minutes, only to shut down again. A diagnostic scanner attached to the car revealed a P1290 code, which lead us to believe the cylinder head temperature gauge may be faulty. Replacing the cylinder head temperature gauge immediately cured the issue and the vehicle is back to operating normally.
The BMW N20 cylinder head temperature sensor monitors the engine's coolant temperature at the top of the engine block. This data is sent to the BMW's DME (engine control unit) where it is used to manage engine operation and performance. If the sensor reads that the coolant in the cylinder head is too hot the DME will send the engine into "limp mode", effectively cutting power to the vehicle and avoiding engine overheating.
The issue that is plaguing many BMW owners with the N20 engine is the premature failure of the sensor (the 2014 320i that we repaired for this article only had 43,000 miles). BMW N20 cylinder head temperature sensor failure may cause the DME to falsely assume the engine is overheating, forcing the vehicle to cut power and eventually shut down.
Replacing the BMW N20 cylinder head temperature sensor is a very simple procedure, and depending on the model you are working on can take as little as 15 minutes. It is conveniently located on the front of the engine, and requires a 22mm deep socket to remove and reinstall it.
View the detailed parts diagram for this repair.
Includes detailed part diagrams, part numbers and links to purchase all of the required components needed to complete this repair.
Section 1 - Removing and Installing the Cylinder Head Temperature Sensor
Removing and installing the BMW N20 cylinder head temperature sensor in your four-cylinder engine is very simple. It is conveniently located on the front of the engine and easily accessible without having to clear any parts out of the way.- Locate and identify the cylinder head temperature sensor. It is on the front of the engine as shown in the images below.
- Pinch in the metal locking clip on the temperature sensor's electrical plug. Pull the plug off of the sensor.
- Using a 22mm deep socket wrench, remove the BMW N20 cylinder head temperature sensor from the cylinder head.
- A small amount of engine coolant may drip out of the open hole after the sensor is removed, so have a rag ready.
- Install the new sensor into the cylinder and finger tighten. Torque the new BMW N20 cylinder head temperature sensor to 11 Nm (8 ft-lb).
- It is always good practice to spray the electrical plug liberally with CRC Electronic Cleaner to remove any dirt, oil or old coolant.
- Replace the plug. Make sure it snaps securely into place.
BMW N20 Cylinder Head Temperature Sensor Replacement Finished
