Sensors

All vehicles will lose some degree of performance due to heat soak under the right operating conditions.  Engine management systems constantly monitor operating conditions and modifying parameters based on sensor inputs. BMW integrated the intake air temp sensor in the MAF housing on models such as the E39 M5, and, being sandwiched behind a hot radiator and in some applications next to an even hotter valve cover, this is less than ideal for performance applications. Absorbing excess heat from its surroundings, the MAF can’t shed it fast enough, and the ECU reads an inaccurately high intake air temperature. Compensating for this false hot air measurement, the ECU pulls timing and runs a richer fuel mixture, resulting in a significant loss of torque.

What can you do?  Locate an intake air temp sensor in a location where it can properly measure incoming air temps and where it's less prone to heat soak. Mounting the sensor further away from the heat source and isolating it from the MAF housing, it can both resist the effects of heat soak longer and respond to temperature changes more quickly.  The result is you’ll experience reduced torque loss and more consistent power output when you’re pushing your engine hard. 

The Turner engineering team was initially skeptical of the claimed performance benefits of this modification. They first set out validate the functionality and performance benefit of a temp sensor relocation. Replicating stop-and-go traffic heat soak in a 2001 540i was a simple task in a controlled environment - their dynometer. First the car was heat soaked to simulate being stuck in traffic or moving at low speeds by running the car four times on the dyno with the dyno's cooling fans disabled. The fans were then turned on for three more runs to observe the recovery rate once air flow was reintroduced. The test: following this procedure once with a stock IAT, and once with their relocation kit in place. 

The result? Turner recovered 11lb-ft torque at 2500rpm through use of their relocation kit, with even greater recovery to be found for M5 owners. Here are the heat soak-related torque losses Turner experienced:

Stock IAT location:
18rwtq at 2500rpm
10rwtq at 3000rpm
9rwtq at 3700rpm

Turner IAT Relocation:
7rwtq at 2500rpm
5rwtq at 3000rpm
5rwtq at 3700rpm

**Click here for installation instructions**

The Turner engineering team designed a complete plug and play kit (unlike all other options on the market) that makes for quick, easy, and reversible installation. Weather-sealed connectors keep out the elements, while sheathed wiring offers a clean appearance underhood. With a harness nearly 3 feet long - the Turner IAT relocation kit offers flexibility in positioning, but not too long that you're left with unsightly excess wiring. Turner recommends positioning the sensor in a location away from engine heat, but still within the intake ducting to achieve accurate intake temp readings - such as the far side of the base of the airbox. Vehicles with cold air intakes with cone-style filters can even position the sensor in the end of the filter. Simply drill a hole in your (cool) location of choice and plug in the harness. More information including installation instructions and some good examples of sensor mounting locations can be found in our DIY PDF. 

We include everything you need to relocate your IAT, just select your desired sensor brand below - Genuine BMW or original equipment Beru.

Also the perfect plug-n-play option for anyone looking to upgrade their intake to utilize an Alpha-N tune!

Note for vehicles with M62 engine: applicable to 1999 and up

This sensor monitors the position of the Valvetronic eccentric shaft and feeds data back to the ECU. The common issue with this sensor is that it gets contaminated with oil and fails. It doesn't give a fault code or check engine light, however. What you would notice is sluggish driving, hesitation, poor performance, jerky shifts from an automatic, and other drivability issues. These types of issues are typically diagnosed as ignition coils (which are their own issue altogether) but this sensor may also be faulty.

The eccentric shaft sensor is located at the front of the cylinder head and is only accessible with the valve cover off. It's easy to check for oil by removing the engine trim cover (the outer cover with the BMW roundel), unplug the sensor, and look inside. If oil is present inside, or even on the valve cover itself, the sensor is likely contaminated or ready to fail. You can wipe or clean the oil from sitting inside the sensor but it will come back.

If you're planning this job make sure you have our Valve Cover Overhaul Kit, which includes a new seal for the eccentric sensor as well as the rest of the valve cover and Valvetronic gaskets. You can add the valve cover set from the options below.

OEM VDO is one of the largest OE providers in the world, supplying numerous vehicle brands, including BMW, with many of their genuine parts that build the vehicle before they ever reach the car lot. Entrusted by many of the top names in automotives and with their proven history of reliability, it makes all of us here at Turner confident that their line of OEM replacement parts are a perfect option to restore your vehicles original operation and performance. The same great quality or higher than Genuine BMW parts at a lower cost.

As a leading source of high performance BMW parts and accessories since 1993, we at Turner Motorsport are honored to be the go-to supplier for tens of thousands of enthusiasts the world over. With over two decades of parts, service, and racing experience under our belt, we provide only quality performance and replacement parts.  All of our performance parts are those we would (and do!) install and run on our own cars, as well as replacement parts that are Genuine BMW or from OEM manufacturers. We only offer parts we know you can trust to perform!

This item fits the following BMWs:
2008+ E82 BMW 128i
2006-2011 E90 BMW 325i 325xi 328i 328xi 328i xDrive 330i 330xi - Sedan
2006-2012 E91 BMW 325xi 328i 328xi 328i xDrive - Wagon
2007-2013 E92 BMW 328i 328xi 328i xDrive - Coupe
2007-2013 E93 BMW 328i - Convertible
2006-2010 E60 BMW 525i 525xi 530i 530xi 528i 528xi 528i xDrive
2010+ F07 BMW 535i GT, 535i xDrive GT, 550i GT, 550i xDrive GT
2011 F10 BMW 528i
2006-2010 E83 BMW X3 3.0i X3 3.0si
2011 F25 BMW X3 xDrive28i
2007-2010 E70 BMW X5 3.0si X5 xDrive30i
2006-2008 E85 BMW Z4 3.0i Z4 3.0si
2009+ Z4 BMW Z4 sDrive30i