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Automatic Transmission Oil Cooler

2003 - 2005 BMW Z4 Transmission Oil Cooler (OEM)

Only 1 left in stock
$89.95

ℹ️ Product Notes

This is a used part. It is an auxiliary transmission oil cooler for vehicles with a 3.0L engine. Please note that one line on this cooler is dented.

Fits automatic transmission models only. Please verify your original part number matches 17227505826 before ordering.

Original Part #(s): 17221436258, 17227505826
Condition: Excellent (A)
Like new, minimal to no wear
86,810 miles
Odometer reading when part was removed
See Other BMW Z4 Automatic Transmission Oil Coolers
SKU #
9259701-5031MB.414

Why Buy Used OEM Parts?

✓ Quality-Verified: Every used OEM part we sell has been professionally inspected and tested to ensure it meets our quality standards. While it may show some cosmetic wear from previous use, it's fully functional and ready to install.

✓ Original Equipment: This is a genuine OEM (Original Equipment Manufacturer) part - the exact same part that came with your vehicle from the factory. It's designed specifically for your make and model, ensuring perfect fitment and performance.

✓ Works Like New: Despite some visual wear, this part will perform just as well as a brand new one. The internal components and functionality are intact, giving you the same reliability you'd expect from OEM quality.

✓ Significant Savings: Save 50-80% compared to buying new! Used OEM parts offer exceptional value - you get factory quality at a fraction of the cost. It's the smart choice for budget-conscious vehicle owners who won't compromise on quality.

✓ Risk-Free Purchase: We stand behind our used parts with a generous 6-month warranty, 30-day returns, and 100% money-back guarantee. If it doesn't work out for any reason, simply return it for a full refund. You have nothing to lose!

🛡️ 30-Day Returns + 6-Month Warranty - Buy with Confidence!

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Vehicle Fitment Guide

This part fits the following vehicles:

BMW
Z4 2003-2005 (tapclick to expand)(tapclick to hide)
Swipe left/right to see more info
SubmodelSUB-
MODEL		 Body Style Years Engine Attributes
2.5i Convertible 2003 - 2005 L6 2.5L RWD | Automatic | Fits models with automatic transmission only
3.0i Convertible 2003 - 2005 L6 3.0L RWD | Automatic | Fits models with automatic transmission only

⚠️ Important: Please verify your vehicle's year, make, model, and specifications before ordering. If you're unsure about fitment, contact our customer service team for assistance.

Policies

Shipping & Handling

  • Standard shipping: 3-7 business days via UPS Ground
  • Parts are carefully packaged to prevent damage during transit

Returns (30 Days)

We accept returns within 30 days of delivery for this part.

  • Defective parts: We will replace the part or issue a refund at our discretion
  • Electronic parts: Must be returned with the sealed inspection bag unopened. The clear bag allows full visual inspection before opening. Once opened, electronic parts can only be exchanged for a replacement if defective — no refunds
  • Programming: "Needs to be programmed to my vehicle" is not a valid return reason. Many modules require dealer programming — we're happy to help connect you with resources if your dealer says it's not programmable
  • Return shipping: We cover return shipping as part of our 100% money-back guarantee
  • Parts must be returned in original packaging and unmodified condition
  • Poorly packaged returns that arrive damaged will not be credited

6-Month Warranty

All used parts include a 6-month warranty from the date of purchase.

  • If your part fails within 6 months, we will send a replacement
  • Refunds are only issued if we cannot provide a suitable replacement
  • Warranty covers defects — not installation errors, misuse, or damage after installation

Note: Warranty is for replacement, not refund. A part failing on day 80? We'll replace it. But the return window for refunds is 30 days.

Damaged in Shipping?

If your part arrives damaged:

  • Stop immediately — do not install the part
  • Keep all original packaging and boxes
  • Take clear photos of the damage and packaging
  • Contact us within 48 hours of delivery

We will handle the carrier claim. You are not responsible for shipping damage — we just need your help documenting it.

Order Cancellation

Orders can be cancelled before shipment for a full refund. Once shipped, cancellations follow our return policy.

Symptoms & Diagnosis

Warning Signs of a Failing Transmission Oil Cooler

  • Transmission overheating: Your car might run hotter than usual.
  • Slipping gears: The transmission might struggle to shift smoothly.
  • Rough shifting: Shifts might feel jerky or harsh.
  • Transmission fluid leaks: Look for red or brown fluid under your car.
  • Unusual noises: You might hear whining or clunking sounds from the transmission.

Testing the Transmission Oil Cooler

  1. Check the fluid: Inspect the transmission fluid for a burnt smell or dark color. This indicates overheating.
  2. Inspect for leaks: Look for leaks around the cooler and its connections.
  3. Pressure test: A mechanic can pressure test the cooler to check for internal leaks.
  4. Temperature check: Compare the temperature of the fluid entering and exiting the cooler. A significant difference indicates a problem.

Common Failure Causes

  • Corrosion: Road salt and debris can corrode the cooler over time.
  • Leaks: Cracks or punctures can cause leaks.
  • Clogging: Debris can clog the cooler, reducing its efficiency.
  • Internal damage: Overheating or high pressure can damage the cooler internally.

Buyer's Checklist

What to Look for When Buying

  • Condition: Choose a part that is in good condition, free from damage or corrosion.
  • Compatibility: Make sure the part is designed for your specific BMW model and year.
  • Reputation: Buy from a reputable source that offers warranties and guarantees.

Quality Indicators

FeatureUsed OEMRefurbished OEMNew Aftermarket
OriginOriginal BMW partOriginal BMW partThird-party manufacturer
TestingTested and inspectedTested and restoredMeets OE specifications
Wear & TearMay show some wearMinimal wearBrand new
PriceGenerally the lowest priceMid-range priceVaries, can be budget to premium

What's Typically Included

  • The transmission oil cooler itself.
  • Mounting brackets (sometimes).
  • Seals or O-rings (sometimes).

Installation Overview

Difficulty Level and Estimated Time

  • Difficulty: Intermediate
  • Estimated Time: 2-4 hours

Special Tools Needed

  • Socket set
  • Wrench set
  • Screwdrivers
  • Torque wrench
  • Fluid catch pan
  • Hose clamps

Critical Steps and Tips

  1. Drain the transmission fluid: Properly drain the old fluid before removing the cooler.
  2. Disconnect the lines: Carefully disconnect the transmission fluid lines from the cooler.
  3. Install the new cooler: Mount the new cooler securely.
  4. Reconnect the lines: Reconnect the fluid lines, ensuring they are properly tightened.
  5. Refill the fluid: Refill the transmission with the correct type and amount of fluid.
  6. Check for leaks: Inspect for leaks after installation.

DIY vs. Professional Installation

  • DIY: Possible for experienced DIYers with the right tools and knowledge.
  • Professional Installation: Recommended for those unfamiliar with automotive repair.

Buying Options

Used OEM

  • Best value for money.
  • Genuine factory parts.
  • Tested and inspected to ensure proper function.
  • Significantly lower price than new.

Refurbished OEM

  • Factory parts that have been professionally restored.
  • May include new components.
  • A good balance of price and quality.

New Aftermarket

  • Brand new parts from third-party manufacturers.
  • Built to meet OE specifications.
  • Can be a cost-effective option.

Typical Lifespan

How Long This Part Normally Lasts

  • Typically lasts 75,000-150,000 miles.

Factors That Affect Longevity

  • Driving habits: Aggressive driving can shorten the lifespan.
  • Maintenance: Regular fluid changes can extend the lifespan.
  • Environmental conditions: Extreme temperatures and road salt can accelerate wear.

Price Ranges

Budget vs. Mid-Range vs. Premium

  • Used OEM: $50 - $150
  • Refurbished OEM: $100 - $250
  • New Aftermarket: $80 - $300

Labor Cost Considerations

  • Labor costs can range from $200 - $500, depending on the shop and location.

Total Job Cost Estimates

  • Total cost can range from $250 - $800, depending on the parts and labor involved.

Vehicle-Specific Notes

Known Issues

  • Some models are prone to leaks at the cooler connections.
  • Overheating can be a common issue in certain driving conditions.

TSBs or Common Complaints

  • Check for any Technical Service Bulletins (TSBs) related to the transmission oil cooler on your specific BMW model.
  • Research common complaints in online forums to identify potential issues.

Verification After Install

How to Confirm Proper Operation

  • Check the transmission fluid level after installation.
  • Monitor the transmission temperature gauge.
  • Test drive the vehicle to ensure smooth shifting.

What to Look/Listen For

  • No leaks around the cooler or connections.
  • Normal transmission temperature.
  • Smooth and consistent shifting.
  • No unusual noises from the transmission.

FAQ

Q: How do I know if my transmission oil cooler is bad?
A: Common signs include transmission overheating, slipping gears, rough shifting, and fluid leaks.

Q: Can I drive with a bad transmission oil cooler?
A: It's not recommended. Driving with a bad cooler can cause serious damage to your transmission.

Q: How often should I replace my transmission oil cooler?
A: There's no set replacement interval, but it's a good idea to inspect it regularly and replace it if you notice any problems.

Q: What type of transmission fluid should I use?
A: Use the type of fluid recommended in your BMW's owner's manual. Using the wrong fluid can damage your transmission.

Q: Is it difficult to replace a transmission oil cooler myself?
A: It can be challenging, especially if you're not familiar with automotive repair. Professional installation is recommended for most people.

Part Specifications

OEM Part Numbers:

  • BMW: 17221436258, 17227505826

Fits Years: 2003 2004 2005

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