MOPAR 68139779AC Engine Mount Isolator Rear

( Manufacturer Part Number: 68139779AC ), ( Part Type: Engine Mount ), ( Genuine Oem: Yes ), ( Manufacturer Warranty: 1 Year ), ( Fitment Type: Direct Replacement ), ( Parts Included: Only Part Reference 8 On The Diagram Is Included ), ( Replaces Part Number: 68072778ab, 68072778ac, 68139779aa, 68139779ab )

Review MOPAR Genuine Engine Mount Isolator Rear

The **Mopar 68139779AC Engine Mount Isolator (Rear)** is a high-performance, precision-engineered component designed specifically for Ford vehicles equipped with the iconic 5.0L (302 cubic inch) Coyote or Modular V8 engines, including models like the Mustang, F-150, Expedition, and Navigator. This rear engine mount isolator serves as a critical vibration-dampening and noise-reduction component, ensuring a smoother, quieter, and more refined driving experience while protecting the engine bay from excessive road-induced vibrations. Crafted from durable, high-grade rubber with a reinforced steel insert, the isolator is engineered to absorb and dissipate harmonic forces generated by the engine, transmission, and drivetrain, thereby reducing harshness in the cabin and minimizing wear on surrounding components. Its unique conical design and optimized rubber compound provide superior isolation at multiple frequencies, making it an ideal upgrade for both stock and modified vehicles seeking enhanced comfort and longevity. The 68139779AC is a direct replacement for the factory part, ensuring a perfect fit with no modifications required, and is built to withstand the rigors of daily driving, high-performance applications, and extreme temperatures, from freezing winters to scorching summers. Whether you're looking to eliminate road noise, reduce engine mount fatigue, or simply restore your vehicle to factory specifications, this isolator delivers reliable performance and durability, reinforcing the structural integrity of your powertrain while maintaining the integrity of your vehicle s suspension and drivetrain alignment.

**Pros and Cons of buying a Mopar 68139779AC Engine Mount Isolator (Rear)**

The **Mopar 68139779AC** is a rear engine mount isolator designed for certain Chrysler, Dodge, and Jeep vehicles (commonly found on 3.6L Pentastar V6 engines). Below is a detailed breakdown of its advantages and disadvantages.

### **Pros**

1. **OEM Quality and Fitment**

The part is manufactured by Mopar, Chrysler s official aftermarket division, ensuring it meets the same engineering standards as the original equipment. It is designed to fit directly into the vehicle s mounting system without modification, reducing the risk of installation errors.

2. **Improved Vibration Reduction**

Engine mount isolators are specifically engineered to dampen vibrations and road noise, enhancing cabin comfort. The rubber compound used in these mounts is formulated to absorb harmonic vibrations, which can be particularly noticeable in V6 engines like the Pentastar.

3. **Extended Engine and Transmission Life**

By isolating the engine from excessive vibration, the isolator helps reduce stress on the engine mounts, transmission, and drivetrain components. This can prevent premature wear on gaskets, seals, and mounting hardware, potentially extending the lifespan of these parts.

4. **Compatibility with Aftermarket Upgrades**

If you ve installed performance parts (e.g., exhaust, intake, or suspension modifications), a properly functioning isolator ensures that these upgrades don t introduce unwanted vibrations or noise. It also helps maintain proper alignment of the engine bay components.

5. **Ease of Installation**

The part is designed for straightforward replacement, typically requiring only basic tools. Most users can install it in under an hour, especially if they have access to a lift or jack stands. Mopar provides clear installation instructions, reducing the likelihood of mistakes.

6. **Cost-Effective Solution**

Compared to full engine mount replacements or more complex suspension work, the isolator is a relatively inexpensive fix. Pricing is competitive with other aftermarket brands, offering good value for the performance improvement it provides.

7. **Reduction in Road Noise Transmission**

Beyond vibration isolation, these mounts help block road noise from transferring into the cabin, contributing to a quieter driving experience particularly useful in vehicles where engine noise is already prominent.

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### **Cons**

1. **Limited Lifespan Compared to Full Mounts**

While isolators are durable, they are not as robust as full engine mounts. They may wear out faster, especially in vehicles with rough driving conditions, aggressive acceleration, or frequent off-road use. Replacement intervals may be shorter than those of traditional mounts.

2. **Potential for Misalignment**

If the isolator is not installed correctly (e.g., improper torque or misalignment with the engine or transmission), it can lead to uneven load distribution. This may cause additional stress on adjacent mounts or even the engine itself, potentially leading to rattles or drivability issues.

3. **Not a Permanent Fix for Underlying Issues**

If the original engine mounts are worn or damaged, replacing just the isolator may not fully resolve vibration problems. In some cases, the full set of mounts (or even the transmission mounts) may need attention for a complete solution.

4. **Compatibility Concerns**

While the 68139779AC is designed for specific vehicles (e.g., 2011 2020 Chrysler 200, Dodge Avenger, Jeep Patriot/Compass with the 3.6L engine), fitment can vary slightly by model year or trim. Double-checking the vehicle s VIN or consulting a fitment guide is essential to avoid purchasing the wrong part.

5. **Quality Variability in Aftermarket Alternatives**

While Mopar is a reputable brand, some cheaper aftermarket alternatives may use lower-quality rubber compounds or substandard manufacturing processes. These inferior parts may degrade faster, leading to premature failure and potential damage to surrounding components.

6. **May Not Address All Noise Sources**

If the vehicle has other sources of noise (e.g., exhaust leaks, intake rattles, or suspension issues), replacing just the isolator will not eliminate those sounds. A thorough diagnostic may be required to pinpoint the exact cause of unwanted noise.

7. **Potential for Over-Tightening**

Engine mounts (including isolators) should not be over-tightened, as this can damage the rubber or cause stress cracks. Improper torque can lead to premature failure or even mount failure, which could result in engine movement or drivability issues.

---

### **Conclusion**

The **Mopar 68139779AC rear engine mount isolator** is a practical and effective solution for reducing vibration, road noise, and stress on the engine and drivetrain in compatible Chrysler, Dodge, and Jeep vehicles. Its OEM-quality construction, ease of installation, and cost-effectiveness make it a strong choice for drivers experiencing vibration or noise issues. However, it is not a universal fix it must be installed correctly, and underlying mount or drivetrain issues may still require attention.

If your vehicle is experiencing excessive vibration, rattles, or noise that you suspect is related to the rear engine mount, this part is worth considering as a targeted upgrade. For best results, ensure proper installation and consider replacing all mounts (front and rear) if they are worn or damaged.

### **Recommendation**

- Your vehicle is confirmed compatible (check your VIN or model year).

- You are experiencing vibration or noise issues localized to the rear engine mount.

- You prefer an OEM-quality part with reliable fitment.

- You plan to install it yourself or have a trusted mechanic perform the job.

- The isolator alone does not resolve the issue (indicating other mounts or components may need replacement).

- You are on a tight budget and cannot afford the part (though it is reasonably priced).

- You suspect the problem is unrelated to the engine mounts (e.g., exhaust, suspension, or drivetrain issues).

For long-term reliability, pairing this isolator with a full set of engine mounts (if needed) and ensuring all fasteners are properly torqued will maximize its effectiveness. Always follow the installation instructions carefully to avoid misalignment or damage.

Details:

Do it right the first time, choose us. Shipping Carrier substitutions may be made at our determination in an attempt to reduce shipping cost the customer. Electrical parts are not returnable. Parts must be resalable and in the original packaging.

In stock orders ship within 48 hours.

part #: 68139779ac prices

• $87.71-$187.43

specifications engimou:

• for makes: Mopar
• mpn: 68139779ac
• part type: Engine Mount
• genuine oem: Yes
• manufacturer warranty: 1 Year
• fitment type: Direct Replacement
• parts included: Only Part Reference 8 On The Diagram Is Included
• replaces part number: 68072778ab, 68072778ac, 68139779aa, 68139779ab

payments engimou:

• credit card: Diners-club
• wallet: Google-pay
• other

offer engimou:

• options: Ship-to-home
• quantity: 4
• started: January 31, 2026
• availability: In Stock
• sold: 0

seller engimou:

• city: Norco, California
• # reviews: 550
• rating: 99.1%

general engimou:

• condition: New
• Car Truck Parts Accessories > Engines Engine Parts > Engine Mounts

returns engimou:

• time: 30 Days
• paid by: Seller
• policy: Returns Accepted

shipping engimou:

• type: Fixed
• service: Standard
• class: Standard
• cost: $25.92
• transit: 5-11 Days

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