When selecting a vehicle, a few of the most important considerations are the reliability and performance of the engine. This is the heart of the vehicle, and problems with the engine can be catastrophic. Jeeps have a reputation for reliability, but there are some Jeep 3.7 engine problems.
What are the common Jeep 3.7L engine problems?
The most commonly reported issues are:
- Defective valve seats that can lead to engine failure
- Piston ring landings can cause engine sludge buildup
Most reviews suggest that the 3.7L isn’t a bad engine. Many owners rave about its long-term reliability. It is prone to a few problems that you should be on the lookout for if you own or are considering a Jeep with the 3.7L (225.8 ci) engine.
Being aware of these problems may help you prevent major engine failure.
The Jeep 3.7L
The 3.7L V6 engine (2002-2012) was used in many Chrysler vehicles, including Jeep. It can be found in the Jeep Cherokee, Grand Cherokee, Liberty and Commander.
It underwent a few upgrades over the years, but they didn’t seem to have a significant impact on its reliability. The 3.7L was based on the 4.7L (286.7 ci) V8. It’s essentially the same design, only the 3.7L has six cylinders and is a liter smaller than the 4.7L.
The block is cast iron with a 90-degree angle between the cylinder banks. This was a very common design in years past, but it was never optimal. The cylinder heads are aluminum, and there are two valves per cylinder. It has single overhead camshafts on each cylinder bank.
The engine is considered middle of the road. Some owners claimed it is underpowered in heavier vehicles. With 210 horsepower and 235 lb-ft., the specs aren’t impressive.
The biggest complaint is that it is slow to accelerate. However, most owners state that the power is reasonable for a daily driver and within the expected range for a V6 engine.
Jeep 3.7L Engine Problems
Defective Valve Seats
The valve seats are pressed onto the cylinder heads, and they are made of powdered metal. Over time, the valve seats can expand. When this happens, it causes problems with the pistons and the contact with the valve.
If the problem isn’t caught early on and the valve seat breaks, it can cause catastrophic failure. The piston, cylinder wall and valve can begin to deteriorate. If pieces of metal make it into the manifold, it compounds the problem.
Once the valve seats are broken, the likely outcome is that the engine will need to be rebuilt or replaced. If the problem is caught early, it may be possible to just replace the valves and valve seats.
Piston Ring Landings
The piston ring landings are not optimally designed. This can make the engine run hotter than it should be. The problem is compounded by drain holes in the head and block that are too small. This combination can cause sludge to build up in the engine.
Over time, this can cause blockages in the engine and prevent oil from going where it is needed. The unfortunate end comes from damage to the engine due to oil starvation and overheating and, eventually, engine seizure.
If the problem continues to the point of engine damage or seizure, the engine will probably have to be rebuilt or replaced. Regular maintenance and temperature monitoring may help prevent damage from occurring.
