BMW Engine Parts for BMW 5 Series E39 (1996-2003)

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

Introducing our newest upgrade for your E36: a full billet aluminum valve cover engineered to eliminate factory and aftermarket valve cover issues. If you're familiar with our new Turner Motorsport products for 2023 and 2024 you can tell that our engineering team at Turner has a focus on older chassis, especially the E36.

Our valve cover is designed to fit some of the best engines BMW ever came out with, single vanos M50/M52 and S50/S52. Not only are these great motors in general and deserve an upgraded valve cover but they are also prime for boosting. When adding boosting you will be introducing heat which can wreak havoc on your ignition system and make your factory valve cover extremely prone to failure.

The reality of the M5x/S5x motors is that the plastic valve covers are sub-par and the magnesium versions are no longer available from BMW and even those can even warp. You can end up replacing your valve cover time and time again dealing with issues if you prefer but the option is here for you. The last valve cover you buy for your E36.

Our engineers designed this valve cover with experience and personal passion that offers a plethora of benefits for your M5x/S5x motor. Whether you plan to cherish your E36 for years to come or envision a turbocharger upgrade, our valve cover is the ultimate solution. It boasts rugged durability and brilliant aesthetics, ensuring it's a perfect fit for any enthusiast.

Featuring full 6061 billet construction and a type-3 hard coat finish, our valve cover is built to endure extreme conditions and rigorous use. Whether you opt to retain your factory PCV setup or upgrade to a catch can for racing purposes, the cover provides dedicated, direct-fit ports for both configurations.

The base kit includes all the necessary components for a seamless installation. Additionally, the description provides part numbers for optional replacements and add-ons, ensuring you have everything you need to complete your install.

Features:

Integrated -10AN ORB ports for a catch can setup to keep your intake free from oil in racing applications
Compatible with factory M5x/S5x ignition coil packs
Compatible with Red Top "Smart Coils" (Audi R8) for standalone ECU applications
Stainless steel coil pack heat shield for enhanced protection in factory and top mount turbocharger applications
Compatible with factory oil cap
Modular heatshield with bendable tab to accommodate 96-99 coil harness that crosses over the top of the exhaust manifold
Online instructions included for PCV, heatshield and coil pack installation
Benefits:

Leak-free - Never deal with a warped valve cover again thanks to the full billet aluminum construction
Retains all factory PCV functions
Protected ignition coils and wiring
Superior heat resistance - Will not melt like plastic replacement valve covers
Durable and clean anodized coating able to withstand excessive engine and exhaust temperatures
Optimized oil path for vanos/timing chain lubrication
Design:

Full 6061-T6 Billet Aluminum
Type 3 black hard coat for increased durability and thermal capacity
Compatible with all Single Vanos M5x/S5x engines
Heat shield with black anodized Turner back plate for a clean and durable finish
Designed to utilize M50/S50 valve cover gasket - fits all M50, M52, S50, S52
Kit options:

The base kit includes:
Billet Valve Cover
Heat Shield, PCV Adapter - QTY 1
-10AN ORB Block-Off Fittings - QTY 2
M50/S50 Valve Cover Gasket Set
Valve Cover Securing Hardware Grommets - QTY 15
Ignition Coil Install Hardware (M6x1, 25mm length) - QTY 12
Heat Shield Install Hardware (M6x1, 12mm length) - QTY 4
Optional Ignition Coils
PCV options:

There are different PCV connections based on year splits for M5x/S5x motors. If you have a damaged or worn-out PCV component please reference the replacement component that matches your motor.

(1995 Only) Valve cover breather connector - P# 11151703710
(1996-1999) Replacement oil separator hose - P# 11151703775
Looking for catch can and or AN lines and fittings?

Right angle catch can feed/return lines - T#26493912
Feed/Return line separator - T#26493913
Universal catch can kit with mounting - T#398786

Upgrade your engine build with Turner's WPC-treated Race Series Bearings, engineered for serious performance enthusiasts. Starting with ACL’s high-performance bearing shells, these Race Series bearings are built to withstand extreme RPMs and stress. Utilizing a "Duraglide" tri-metal construction and a high-strength overlay plate, these bearings offer superior oiling and heat resistance for high-RPM operation.

Our WPC-treated bearings take ACL’s already impressive design and enhance it even further. The WPC treatment process strengthens and smooths the bearing surface by firing high-speed, ultra-fine particles at the bearing shells, reducing friction and improving durability. This advanced surface treatment ensures smoother operation and improved heat dissipation, which are critical for any high-performance engine.

Key Features:

Duraglide Tri-Metal Construction: ACL's Race Series bearings feature a high-strength overlay for enhanced performance. Optimized Oiling: Designed to promote better oil flow during high-RPM conditions. Precise Fitment: Manufactured with OEM-level precision using micron tolerance machining. WPC-Treated for Strength: Surface treatment adds strength and reduces friction for improved engine performance. No Flash Plating: Allows for better heat transfer and bearing retention. Thermal Discharge Process: Smoother, stronger components through WPC’s unique thermal discharge technology. Enhanced Heat and Friction Resistance: Built to combat the biggest enemies of high-performance engines. Don’t settle for standard bearings—choose Turner Motorsport WPC-treated Race Series Bearings for the ultimate engine performance upgrade. Perfect for your next engine rebuild or rod bearing service!

When we designed this catch we wanted to have the most function options available, the best separation method, and the easiest to service. The Turner engineered catch cans offer a pre-setup design based ion desired flow direction, however this does not limit you to this flow. The inner baffle orientation can be easily adjusted to flow in both directions in case you decide to move this catch can to a different vehicle. A 4 chamber system  baffle system inside the catch can was engineered to create multiple changes in the direction of airflow within the separator to cause oil droplets to fall out of suspension before exiting the catch can. Having a closed / recirculated design reduces oil ingestion and promotes cleaner emissions and odor-less operation.

Our catch can was also designed with the idea that the cans fill level can easily be checked with a top mounted dipstick and an optional use bottom drain hole. The drain hole can be used with a valve and hose to be mounted at a lower area of the vehicle so when you're doing an oil change you can drain the catch can.

Features:

• 6061-T6 billet machined body, anodized black for lasting protection and appearance
• Strategically positioned 4 chamber baffle system maximizes oil / air separation 
• Knurled and black anodized oil dipstick makes inspecting oil volume of reservoir clean and simple
• Sealed with a pre-installed viton O-Ring
• Includes 2.5mm allen key to remove baffle plates for cleaning
• Engineered to create multiple changes in the direction of airflow within the separator to cause oil droplets to fall out of suspension before exiting the catch can
• Closed / recirculated design reduces oil ingestion and promotes cleaner emissions and odor-less operation
• Optional use drain hole (valve and hose sold separately, watch for our model specific drain kits!)

Through experimentation and data acquired from our E36 World Challenge Touring Cars, it was discovered that in long corners and under heavy braking that there was an oil starvation problem in the M50 and M52 engines. This system was developed to keep oil in the sump and eliminate the starvation problem. After several iterations, further testing and data acquisition in the Touring Cars showed that this system eliminates the problem of oil starvation. This is a less expensive alternative to replacing the stock oil pan with the factory BMW M3 Lightweight oil pan, while still achieving the similar results.

*Requires Professional Welding

Installation instructions (E36/Z3 Oil Pan Baffle for M50, M52, S50, S52 engines)

This item fits the following BMWs:
1992-1999 E36 BMW 323is 323ic 325i 325is 325ic 328i 328is 328ic M3
1992-1995 E34 BMW 525i
1997-1998 E39 BMW 528i
1997-1998 Z3 BMW Z3 2.8
1998-2000 Z3 BMW Z3 M Coupe M Roadster S52

Underdrive Power Pulleys work to 'free up' horsepower. Any accessory that spins from the main drive belt is using up power. That's power that could otherwise be used to move the car. By giving some of that power back to the engine, you can make the car faster! It's like FREE HORSEPOWER!

Underdrive pulleys for your BMW will slow down engine-mounted accessories - the water pump, power steering pump, and alternator*. These systems contribute to 'parasitic losses' - power lost from what the engine could produce if it did not have these systems. Since less energy is used to move them, that power is transferred back to the engine and used to propel the car. Our pulleys give a 10-20% reduction in rotation, releasing up to 11hp on most BMW six-cylinder engines. There's also a small but noticeable improvement in throttle response too! We have done extensive testing and development work, both on and off the track, to ensure that the accessory systems function as they should. On our Racing pulley kits we actually underdrive certain components more so we feel our Street pulleys are an ideal compromise between power/torque gains, reliability, and system performance. Our pulley kits have been on the market for over ten years, and used in all of our own cars, with zero component failures related to their use.

Our pulleys are made from T-6061 aluminum and finished in a durable black hard anodize that is very resistant to wear, chemical exposure, and heat. We designed our pulleys to look similar to the factory parts but also to be stronger and, in most cases, slightly lighter too. For example, a Turner alternator pulley is less than half the weight of the stock steel pulley! With our hardcoat aluminum you will never have to worry about a serious failure of a stock plastic pulley. A 'stealth' approach to aesthetics was our goal and we let the results speak for the pulley design. Installation is straight forward and easy with simple hand tools. Removal of the fan is required for access to the front of the engine. Total install time for a 3-piece pulley set should be around 1.5 hours. A new longer belt is included and we also recommend replacing the separate A/C belt, belt tensioners, and the guide and deflection pulleys at the same time.

* Alternator Pulley Options

Bosch or Valeo? BMW built your car with either a Bosch or Valeo brand alternator. Unfortunately, the pulley is not the same for both brands. The brand is usually printed on the black plastic cover of the alternator but may be facing the frame rail or the ground. If you know which brand you have, select your option below and we'll send you the correct alternator pulley for your BMW. Don't know which you have? NO PROBLEM! We can send you both. The 2nd pulley costs $40 but you will receive a refund once we get the un-used pulley back (return shipping not included).

Stereo Systems. We offer our kits in two different ways: the full Power Pulley Kit with all 3 pulleys or as a 2 pulley kit if you do not wish to underdrive your alternator (for large stereo systems or other critical-charging modifications). Our kits have been tested for compatability with the factory premium stereo systems (Harmon Kardon, etc). But any major upgrades from the factory premium systems will work best with our 2 pulley kit and no underdriving of the alternator. For all stock stereo systems the full 3-piece set is recommended because the Turner alternator pulley will help make more power and is also much lighter than the stock pulley.

Additional Info

Clickhere for example dyno graph

Click here for installation instructions.

Turner Pulley Kit contents:

• Turner water pump pulley
• Turner power steering pump pulley
• Turner alternator pulley
• new extended length belt
• instructions
  
  
   
• This underdrive pulley kit fits the following BMW:
  1997-1998 E39 BMW 528i

Underdrive Power Pulleys work to 'free up' horsepower. Any accessory that spins from the main drive belt is using up power. That's power that could otherwise be used to move the car. By giving some of that power back to the engine, you can make the car faster! It's like FREE HORSEPOWER!

Underdrive pulleys for your BMW will slow down engine-mounted accessories - the water pump, power steering pump, and alternator*. These systems contribute to 'parasitic losses' - power lost from what the engine could produce if it did not have these systems. Since less energy is used to move them, that power is transferred back to the engine and used to propel the car. Our pulleys give a 10-20% reduction in rotation, releasing up to 11hp on most BMW six-cylinder engines. There's also a small but noticeable improvement in throttle response too! We have done extensive testing and development work, both on and off the track, to ensure that the accessory systems function as they should. On our Racing pulley kits we actually underdrive certain components more so we feel our Street pulleys are an ideal compromise between power/torque gains, reliability, and system performance. Our pulley kits have been on the market for over ten years, and used in all of our own cars, with zero component failures related to their use.

Our pulleys are made from T-6061 aluminum and finished in a durable black hard anodize that is very resistant to wear, chemical exposure, and heat. We designed our pulleys to look similar to the factory parts but also to be stronger and, in most cases, slightly lighter too. For example, a Turner alternator pulley is less than half the weight of the stock steel pulley! With our hardcoat aluminum you will never have to worry about a serious failure of a stock plastic pulley. A 'stealth' approach to aesthetics was our goal and we let the results speak for the pulley design. Installation is straight forward and easy with simple hand tools. Removal of the fan is required for access to the front of the engine. Total install time for a 3-piece pulley set should be around 1.5 hours. A new longer belt is included and we also recommend replacing the separate A/C belt, belt tensioners, and the guide and deflection pulleys at the same time.

* Alternator Pulley Options

Bosch or Valeo? BMW built your car with either a Bosch or Valeo brand alternator. Unfortunately, the pulley is not the same for both brands. The brand is usually printed on the black plastic cover of the alternator but may be facing the frame rail or the ground. If you know which brand you have, select your option below and we'll send you the correct alternator pulley for your BMW. Don't know which you have? NO PROBLEM! We can send you both. The 2nd pulley costs $40 but you will receive a refund once we get the un-used pulley back (return shipping not included).

Stereo Systems. We offer our kits in two different ways: the full Power Pulley Kit with all 3 pulleys or as a 2 pulley kit if you do not wish to underdrive your alternator (for large stereo systems or other critical-charging modifications). Our kits have been tested for compatability with the factory premium stereo systems (Harmon Kardon, etc). But any major upgrades from the factory premium systems will work best with our 2 pulley kit and no underdriving of the alternator. For all stock stereo systems the full 3-piece set is recommended because the Turner alternator pulley will help make more power and is also much lighter than the stock pulley.

Additional Info

Clickhere for example dyno graph

Click here for installation instructions.

Turner Pulley Kit contents:

• Turner water pump pulley
• Turner power steering pump pulley
• Turner alternator pulley
• new extended length belt
• instructions
  
  
   
• This underdrive pulley kit fits the following BMW:
  2001-2002 E39 BMW 525i 530i

Over time, the factory valve cover hardware on M50, M50TU, M52, M52TU, M54, S50 (US), and S52 engines is subjected to continuous heat cycling, oil vapor, and moisture, causing original cap nuts to oxidize, corrode, or thread-strip during routine maintenance. Our Polished Valve Cover Cap Nut serves as a direct replacement designed to address these common failure points while improving upon overall engine bay aesthetics.

Because maintaining precise gasket compression is critical to preventing oil leaks, these cap nuts and washers are machined directly to OE-style dimensions. This exact fitment allows for direct compatibility with original and replacement valve cover studs (see T#55317643) and ensures the hardware can be torqued precisely to OEM specifications without guesswork. Manufactured to grade 8.8 structural strength standards, the hardware maintains the necessary clamp force required under normal and high-performance engine operating conditions.

To resist corrosion, both the cap nut and washer undergo an electroless nickel plating process during production. Unlike standard zinc coatings that dull or rust over time, electroless nickel provides a uniform layer of corrosion resistance that withstands long-term chemical exposure and extreme temperature swings while giving the hardware a polished, high-end appearance. Each cap nut assembly includes an OE rubber washer seal, ensuring a tight, leak-free barrier that prevents oil from escaping through the mounting studs.

Spark Plug Replacement for Enhanced Engine Performance

Periodic replacement of spark plugs is crucial in averting common problems arising from worn or contaminated plugs. Issues like misfires, reduced power, and a lit Check Engine Light are effectively prevented by timely plug replacements.

Fresh spark plugs not only boost engine performance and fuel efficiency but also play a significant role in reducing engine misfires, subsequently preserving expensive ignition coils and catalytic converters.

Turner Motorsport provides an array of brands, plug configurations, and heat ranges meticulously recommended by OEMs for various European applications, ensuring optimal performance and compatibility.

Benefits:

• Prevents misfires and engine performance issues
• Enhances fuel efficiency
• Reduces strain on ignition coils and catalytic converters
• Recommended by OEMs for European applications

Ensure the correct voltage is being sent to/from the alternator, keep you electrical system safe from excessive voltage peaks that could cause damage to sensitive electronics and blow out fuses. Bosch's high quality unit will give you peace of mind knowing the electrical system will be safe and the voltage will remain steady. OEM replacement for BMW part # 12317559183 and 12317501752.

Cars that have oval or D shaped connector use BMW part # 12317515319

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

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!

Bosch fuel injectors provide the precision manufacturing required for advanced fuel injection systems.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

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!

Knock sensors detect pings in the engine and adjust ignition timing to restore perfect operation. Faulty knock sensors will throw engine codes or even lead to engine damage. Replace your sensor with a reliable, high quality Bosch sensor to ensure proper engine ignition timing.

Bosch # 12141741648 OEM replacement for BMW part # 12141741648.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely s  eupplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

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!

Fits the following vehicles:
1996-09/1999 E39 BMW 540i
1995-09/1999 E38 BMW 740i 740iL
1990-1999 E31 BMW 840Ci

Knock sensors detect pings in the engine and adjust ignition timing to restore perfect operation. Faulty knock sensors will throw engine codes or even lead to engine damage. Replace your sensor with a reliable, high quality Bosch sensor to ensure proper engine ignition timing.

Bosch # 13627568421 OEM replacement for BMW part # 13627568421, 12141709317, and 12141435502.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

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!

If your car has died on the side of the road from a dead battery and you notice flickering or low powered head lights, it's likely your alternator failing. To be sure you are getting a high quality part with a long life-span, choose this OEM Bosch Alternator. This is an OEM replacement for BMW part # 12311407440.

Bosch is one of the largest OEM producers of Genuine BMW and aftermarket parts in the world, providing parts for almost every major automotive manufacturer. Bosch has likely supplied many of the original electrical (and mechanical) parts for your BMW. Thanks to their quality, high durability, and reliability, you should expect a long service life from Bosch products.

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!

A refundable $70.00 core charge must be applied to this alternator. Upon receipt of your rebuildable alternator core, you will be refunded the core charge.

This item fits the following BMWs: 
1999-2003 E39 BMW M5