BMW Z3 1.8 1995-2000 1.9 1995-1999 1.9i 2000-2002 Alternator Bracket Tensioner
Actual Item For Sale
This is a used original BMW component. Please study the actual item photographs carefully because cosmetic marks, oxidation and signs of previous use are normal on a used engine-mounted component.
Important part-number status: the present photographs do not show a sufficiently clear factory number for us to state the number as physically confirmed. Catalogue and visual comparison indicate BMW reference 12 31 1 247 646 / 12311247646 as the principal number to verify before purchase.
BMW Z3 Compatibility Guide
The table below describes the Z3 applications associated with the 12311247646 catalogue reference. The physical item must first be confirmed as that reference before these rows are treated as final fitment.
| Model | Production | Engine | Body | Status |
|---|---|---|---|---|
| BMW Z3 1.8 | 09/1995–09/2000 | M43 / later M43TU | E36/7 2-door Roadster | Catalogue application — VIN check required |
| BMW Z3 1.9 | 09/1995–03/1999 | M44, 140 bhp | E36/7 2-door Roadster | Catalogue application — VIN check required |
| BMW Z3 1.9i | 09/2000–08/2002 | M43TU, 118 bhp | E36/7 2-door Roadster | Catalogue family application — VIN check required |
This catalogue reference is not listed for the Z3 six-cylinder accessory-drive applications. Do not order it merely because the vehicle is a 1995–2002 Z3. This includes Z3 2.0, 2.2i, 2.3, 2.5i, 2.8, 3.0i and Z3 M variants. Z3 Coupé applications must also be verified separately.
Production date matters: a vehicle registered in one calendar year can have been manufactured earlier. The VIN/build date and engine code are more reliable than registration year.
Correct Vehicle-Type Reference Photos
These reference photographs show the correct BMW Z3 E36/7 two-door Roadster body style. They are identification references only; the cars photographed are not the donor vehicle for the item being sold.
Where Is This Part Fitted?
The supporting bracket is fitted in the front accessory-drive area of the four-cylinder engine. It provides the mounting/support geometry for the alternator and related belt-tensioning arrangement.
It does not electronically “control” the vehicle. Its job is mechanical: maintaining the correct position, support and alignment of the alternator, tensioner/pulley system and drive belt.
What This Component Does
The alternator support bracket is a substantial cast metal mounting component forming part of the engine accessory-drive system. Correct geometry is important because the alternator pulley, tensioner and drive belt need to remain correctly aligned while the engine is operating.
The visible main support body is a cast aluminium/alloy component. The exact aluminium alloy grade has not been independently verified and is therefore not claimed in this listing.
Catalogue weight for the bare 12311247646 supporting bracket is approximately 1.58 kg. The photographed item may weigh more where additional tensioner/pulley components remain attached.
Possible Symptoms Of A Fault In This Area
| ✓ | Visible cracking or damage around bracket mounting points |
| ✓ | Alternator or tensioner movement that should not be present |
| ✓ | Accessory belt running out of alignment |
| ✓ | Belt squeal, chirping or abnormal pulley/tensioner noise |
| ✓ | Abnormal or accelerated belt-edge wear |
| ✓ | Tensioner wobble or unstable belt tension |
| ✓ | Charging warning symptoms if the alternator drive belt slips or fails |
These are possible symptoms only and are not a diagnosis. Belt noise can also be caused by the belt, alternator, pulley bearings, tensioner, other accessories or incorrect alignment elsewhere in the drive system.
Why Choose An Original BMW Used Component?
Where the part number is correctly matched, an original BMW component was designed around the vehicle's factory mounting points, fastener positions, alternator location and accessory-drive geometry.
A used original component can also provide substantial savings compared with buying a current new replacement, while avoiding the uncertainty associated with an unknown low-cost reproduction where dimensional tolerances, material specification and component life may be unknown.
The most important factor remains correct part-number and VIN matching. An original component for the wrong engine is still the wrong component.
Other BMW Applications Associated With Reference 12311247646
These are useful part-number cross-references only. They are not permission to order by model/year alone. The BMW catalogue gives a production-start year for these variants but does not provide a safe single end year on the source used here, so no end year has been invented.
| Series | Model / Body | Engine | Catalogue Start |
|---|---|---|---|
| E46 | 318i Touring | M43 | 1999 |
| E46 | 318i Saloon | M43 | 1999 |
| E46 | 318Ci Coupé | M43 | 1999 |
| E46 | 316Ci Coupé | M43 | 1999 |
| E46 | 316i 1.9 Saloon | M43 | 2001 |
| E46 | 316i 1.6 Saloon | M43 | 2001 |
| E36 | 318i Touring | M43 | 1995 |
| E36 | 316i Touring | M43 | 1997 |
| E36 | 318ti Compact | M44 | 1996 |
| E36 | 316i 1.9 Compact | M43 | 1999 |
| E36 | 316i 1.6 Compact | M43 | 1994 |
| E36 | 316g Compact | M43 | 1996 |
| E36 | 318is Saloon | M44 | 1996 |
| E36 | 318i Saloon | M43 | 1998 |
| E36 | 316i Saloon | M43 | 1997 |
| E36 | 318is Coupé | M44 | 1996 |
| E36 | 316i Coupé | M43 | 1993 |
| E36 | 318i Convertible | M43 | 1994 |
Fitting Guidance
- Confirm VIN, engine code and replacement-component identification before dismantling.
- Park securely on level ground, switch the ignition off and allow the engine to cool.
- Disconnect the battery negative terminal following the correct vehicle procedure.
- Record or photograph the accessory-belt routing before removal.
- Remove only the air intake, undertray, shrouding or fan components required for access on that exact engine.
- Safely relieve accessory-belt tension and remove the belt.
- Inspect the belt, tensioner, idlers and pulley alignment while access is available.
- Disconnect/remove or support the alternator as required by the correct workshop procedure.
- Remove the support/tensioner fasteners and withdraw the old bracket without forcing surrounding components.
- Compare the replacement casting, bosses, mounting holes and tensioner/pulley orientation side-by-side.
- Clean the mating areas and inspect threads, fasteners, bushes and surrounding components for damage.
- Install using the correct VIN-specific BMW tightening sequence and torque specifications.
- Route the belt exactly as specified and verify every belt rib is seated correctly.
- Reassemble removed components and reconnect the battery correctly.
- After starting, visually check belt tracking, charging operation and abnormal noise. Stop the engine immediately if the belt runs out of line.
Typical Tools Required
| Metric socket and ratchet set |
| Socket extensions and metric spanners |
| Correct accessory-belt tensioner tool / suitable breaker bar for the engine fitted |
| Calibrated torque wrench |
| Screwdrivers / trim tools for surrounding intake or shroud components |
| Battery-terminal tools |
| Inspection lamp |
| Variant-specific fan/fan-clutch tools where required |
Exact socket sizes and special-tool requirements can vary by engine/build, so they should be established from the VIN-specific repair information before work starts.
Garage Labour Cost Calculator
Planning allowance: approximately 1.5–2.5 labour hours, depending on engine specification, access, corrosion, existing damage and additional components requiring attention.
This is a planning estimate, not a BMW factory flat-rate time. Formula: garage hourly rate × actual labour time.
| Garage Rate | 1.5 Hours | 2.0 Hours | 2.5 Hours |
|---|---|---|---|
| £60/hr | £90 | £120 | £150 |
| £80/hr | £120 | £160 | £200 |
| £100/hr | £150 | £200 | £250 |
| £120/hr | £180 | £240 | £300 |
| £150/hr | £225 | £300 | £375 |
Labour illustration excludes the part, additional replacement components, consumables, diagnostics and any other charges made by the chosen repairer.
Fitting Service Available
THEPARTPILOT can also offer a fitting / repair service subject to workshop availability and prior arrangement. Please enquire through eBay Messages before travelling or making arrangements.
THEPARTPILOT specialises in supplying quality used automotive components, with careful identification and compatibility information designed to help customers order the correct part first time.
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UK & International Delivery
International orders are available through eBay's Global Shipping Programme where the item and destination are eligible. Final availability, postage cost, import charges and delivery options are determined by eBay and displayed at checkout.
Current GSP eligible EU destinations include:
Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain and Sweden.
Current GSP eligible non-EU destinations include:
Antigua and Barbuda, Aruba, Australia, Bahamas, Bahrain, Bangladesh, Barbados, Belize, Bermuda, Bolivia, Brazil, Brunei Darussalam, Cambodia, Canada, Cayman Islands, Chile, China, Colombia, Costa Rica, Dominica, Dominican Republic, Ecuador, Egypt, El Salvador, French Guiana, Grenada, Guadeloupe, Guatemala, Guernsey, Honduras, Hong Kong, Iceland, Indonesia, Israel, Jamaica, Japan, Jersey, Jordan, Kuwait, Liechtenstein, Macau, Malaysia, Maldives, Martinique, Mexico, Monaco, Montserrat, New Zealand, Nicaragua, Norway, Oman, Pakistan, Panama, Paraguay, Peru, Philippines, Qatar, Reunion, Saint Kitts and Nevis, Saint Lucia, Saudi Arabia, Singapore, South Africa, South Korea, Sri Lanka, Switzerland, Taiwan, Thailand, Trinidad and Tobago, Turks & Caicos Island, UAE, Ukraine, Uruguay, USA and Vietnam.
eBay may alter programme eligibility. The destination and shipping service displayed by eBay at checkout are the final authority for each transaction.
Please ensure the delivery address shown during eBay checkout is complete and correct before payment. We must dispatch using the address supplied through the eBay order and cannot simply substitute a different address after checkout.
Fitment & Returns
We put detailed compatibility information into our listings to reduce incorrect orders and unnecessary returns. If you are unsure, please ask for VIN verification before ordering.
Returns are handled in accordance with the return policy displayed on the eBay order/listing, applicable eBay policies and statutory consumer rights.
Where eBay policy legally permits a deduction because a returned item has been used, altered, damaged, is incomplete or has suffered a genuine loss in value, any deduction will be made only in accordance with the applicable eBay process. There is no automatic blanket restocking deduction.
VAT / Global Accounting
Eligible used goods are sold under the applicable Global Accounting / VAT Margin Scheme. Under the margin-scheme rules, VAT is not shown separately as an itemised amount on the relevant sale/invoice.
Buying a quality used automotive component supports the circular economy by keeping usable parts in service for longer, reducing avoidable waste and making use of components that have already been manufactured.
Your purchase also supports an independent local automotive parts business. Thank you for choosing THEPARTPILOT and helping us keep good components working rather than unnecessarily sending them for disposal.