If your Jeep Grand Cherokee won’t turn over and you’re dealing with serious engine damage, you’re not alone. A recent case at GDL Automotive involved a Grand Cherokee that suffered catastrophic engine failure due to spun big end bearings, leaving the engine completely locked up.
After a full diagnosis, the only way forward was a crate engine replacement. The only fix when internal damage is beyond repair.
What Causes Spun Bearings in a Jeep Grand Cherokee?
When most people hear “engine failure,” they assume poor servicing, low oil levels, or overheating. But in this case, oil quality and service intervals were fine, and there was no traditional overheating.
Instead, the likely cause was something more subtle:
Engine laboring due to towing in Drive mode (top gear).
Why Towing in Drive Can Destroy Your Engine
When towing heavy loads, especially in vehicles like the WK2 Grand Cherokee, the transmission often stays in top gear to maintain fuel economy. But here’s the catch: keeping high gear at low RPM under load causes the engine to work too hard at low speeds, known as engine “lugging.”
This constant laboring leads to:
- Excessive heat in the bottom end
- Spun big end bearings
- Loss of oil pressure
- Ultimately, engine seizure
It won’t always trigger a warning light, but inside the engine, critical components are breaking down.
Symptoms of Spun Bearings in a Grand Cherokee
If you’re experiencing any of these signs, it’s worth getting your Jeep inspected ASAP:
- Engine won’t crank or turn over
- Knocking or ticking sounds before engine failure
- Low oil pressure warnings
- Metal shavings in the oil
- Engine completely seizing up
In this case, the Jeep Grand Cherokee engine would not start, and full teardown revealed two spun big end bearings, enough to stop the crankshaft entirely.
Once we confirmed the damage, the next step was a full engine replacement service using a brand new crate motor. Our process included:
- Removing the damaged engine
- Inspecting all surrounding systems (cooling, oiling, transmission)
- Installing the new crate engine
- Testing and tuning to ensure reliability
This level of repair is serious, but done properly, it brings the vehicle back to factory reliability.
How to Tow Safely in a Jeep Grand Cherokee
To avoid destroying your engine while towing, follow these tips:
Use Sport Mode or Manual Mode
Always tow in Sport Mode, not Drive. This keeps the transmission in a lower gear, which helps the engine stay in its optimal RPM range.
Avoid Laboring the Engine
If the engine is struggling to maintain speed, manually downshift. Towing in high gear under load generates excessive heat at the bearings.
Service Your Jeep Regularly
Make sure your oil, cooling, and transmission systems are maintained, especially before long trips with a trailer or caravan.
Need Jeep Engine Repairs or Towing Advice?
At GDL Automotive, we specialise in diagnosing complex Jeep engine problems, including:
- Crate engine replacements
- Spun bearing diagnosis
- Diesel and petrol engine rebuilds
- Safe towing practices for 4WDs and SUVs
If your Jeep Grand Cherokee is not starting or showing signs of internal damage, don’t leave it to guesswork. We diagnose, repair, and rebuild with long-term reliability in mind.
Located near Westfield Hornsby
Call us on (02) 9987 2818
Book online: gdlauto.com.au
