As one of the most popular automobile brands of the century, Jeep vehicles are seen on roads all over the globe.

Constantly evolving, over the years, we’ve seen Jeep make continuous improvements in its models to keep up with progress in the automobile industry. One of the moves that Jeep took to optimize its vehicles was the introduction of a 3.7-liter engine.
This engine was first used in the Jeep Liberty, starting in 2002. After the roaring success of this model, this engine began to be used in other Jeeps as well.
While this engine greatly improved the performance of their vehicles, such as offering 210 horsepower at 5200 RPM, it came with some issues that were apparent to Jeep Liberty owners from the get-go.
Table of Contents
Common Issues with the 3.7 Engine
1. Piston Ring Damage
When you buy a vehicle, you’ll have a list of priorities you’re looking for. Reliability is at the top of the list, along with safety and performance.
With any engine, it’s important for the cylinder wall not to come into contact with the pistons. When they do meet, you risk having an engine failure. The piston ring prevents this from happening.
One of the core issues with the 3.7 engine is the design of the piston ring. While this isn’t very common, the piston rings on some Jeep Liberty vehicles can overheat. This will negatively impact your drive in two ways.
Over time, this heat damage would cause the piston rings to wear out. When they are not in their optimal condition, the piston rings would not be able to do their job properly, and you could have an engine failure.
Secondly, oil can seep through the internal combustion chamber with a damaged piston ring. What this means is that you’ll have higher than usual fuel consumption. Not something you’d want with oil prices soaring sky-high nowadays!
You can avoid this problem by checking on your engine’s cooling system regularly to prevent piston ring damage in its tracks.
2. PCV Valve May Stop Working
A PCV valve is needed to direct the gasses produced in your engine back into the combustion chambers of your vehicle. This prevents these harmful gasses from damaging the environment and your car.
An issue often found in the Jeep Liberty 3.7 is that the PCV Valve tends to be faulty. This causes an accumulation of sludge in your engine. Car owners often do not notice when this is happening. A great way to test if your PCV valve is in a good state is by taking it out of the engine (it looks like a faucet!) and shaking it. If you hear a rattle, your PCV valve is doing fine. If you do not hear anything, your PCV valve has likely been damaged and is clogged.
3. Valve Seat Issues
The intake valves and exhaust have to be sealed to prevent oil from entering your car’s combustion chamber and causing engine failure.
As mentioned before, the 3.7 engine often has issues with cooling. This may cause overheating of your engine and eventually damage the valve seats. This will impact the compression of the cylinders on your vehicle. The cylinder is critical to the health of your vehicle, so when it malfunctions, you will notice a significant decline in performance.
You can prevent this issue from occurring by checking on your engine regularly.
4. Lash Adjuster Issues
Lash Adjusters ensure sufficient valve seating, keep airflow to the engine at an optimized level, and maintain fuel consumption.
The lash adjusters malfunction when the sludge in your engine keeps piling up over time. You’ll notice that your car consumes more fuel than normal, as well as whirring noises from the engine. If you’re noticing these problems, we’d advise you to visit your mechanic and ask them for a replacement adjuster.
Also Read:
What’s Good About the Jeep 3.7 Engine?

While the Jeep Liberty 3.7 engine comes with some undeniable issues, it also has its fair share of advantages.
Firstly, all car owners know the feeling of going to the mechanic to ask for a replacement for a car part and then standing there with your mouth open at the price. Jeep Liberty 3.7 owners will be glad to know that replacement parts for this vehicle are not expensive.
The Jeep Liberty also has excellent protocols for safety in place. It features antilock disc brakes, stability control, side curtain airbags, and active front head restraints. Rear parking sensors are also an added option. If you’re clumsy when reversing, this feature is right for you!
Parting Words
While the Jeep Liberty is a great vehicle for its relatively low price point, it doesn’t come without flaws. It’s great to know where and how this vehicle may be lacking before making the leap and buying it. Even if you already own this vehicle, you will benefit from knowing how things might go wrong. It’s also important to remember that every car has its issues.
The question you should be asking yourself is this; What are your priorities as a vehicle owner, and does the Jeep Liberty live up to those standards?
FAQS
How much does it cost to replace a Jeep Liberty Engine?
If you’re looking to replace your Jeep Liberty, your costs will depend on the state of the replacement. If you’re replacing the engine with an entirely new one, you can expect to spend anywhere between $3000-$4000, depending on your model. If you’re looking for a used engine, the cost will be significantly lower, between $1500-$2000.
Why is the check engine light in my Jeep Liberty on?
If the check engine light on your Jeep Liberty is showing, this may be a sign of a malfunctioning valve seating.
Why is the engine on my Jeep Liberty revving while idle?
If your Jeep Liberty keeps revving even when you have your foot off the accelerator pedal, this may be a sign that the PCV valve may have been blocked with accumulated sludge.
Why is my Jeep Liberty’s engine overheating?
One reason you may be experiencing an overheating Jeep Liberty engine is that there is not enough coolant in the radiator. The coolants help maintain the engine’s temperature and thus help prevent damage to its components. A severely overheated engine may fail over time as essential components such as the cylinder or the piston rings get damaged.
How long will the Jeep Liberty engine last?
The Jeep Liberty 3.7 is a powerful and reliable engine. It will comfortably last you 15 years (or 400,000 miles) with good maintenance. How you drive will also affect this period as well as the regularity of your maintenance schedule.
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