Jeep 2.5 Engine Problems [ 10 Common Problem And Solutions]

The Jeep 2.5 engine is reliable if you use it daily. It works smoothly in almost all Jeeps like the Jeep Wrangler, Jeep Comanche, Jeep Cherokee, etc. But, as it’s not one of the top-tier engines, you may encounter several problems frequently.

So, what are those Jeep 2.5 Engine Problems? Some of those problems are sudden engine shutdown, loud rattling noise while operating, battery drainage, and oil leak. Also, issues with the transmission, starting late, and problems like false starts may occur.

We will enlighten all these reasons and ways to resolve and prevent those problems. So read the article till the end.

Jeep 2.5 Engine Problems & Solutions

In the table below, we’ll have a quick look at the 10 common problems that you will find in the Jeep 2.5 engine. We will also provide the reasons and solutions for those issues.

1. Loud knocking sound of the engine

Sometimes you can hear a loud rattling noise coming from the engine. It generally occurs when the rod knocks on the engine. Missing insulation makes the sound louder. 

Also, low oil pressure, defective starter, engine ping, and damaged harmonic balancer can be responsible for these disturbing loud knocking sounds.


  • Check for a coolant leak and fix it
  • Take moderate care of your engine
  • For a complex fix, visit a mechanic

2. Don’t start on the first try

The Jeep 2.5 engine may have an issue with the starting. When you try to start the engine, it doesn’t start on the first try. You have to try multiple times to start your car.

Generally, this issue occurs due to inappropriate fuel pressure. Loose connections due to broken grounds, loose grounds, and melted wires also can be responsible for this problem. Sometimes, jammed throttle bodies and injectors become the culprit behind this starting issue.


  • Try to clean the throttle body
  • Add a new downstream O2 sensor
  • Check fuel pressure and frame-mounted fuel filter. Then, fix issues with those.
  • Have a good visual check of all the wiring. Make sure there are not any loose connections

3. False starting

Normally, in this issue, when you try to start your engine, the engine starts for a few minutes. After that, it stops again rather than going forward.

Insufficient power in the ignition is the main reason behind this. When the fuel pump isn’t receiving enough power, it can’t start the vehicle properly.


  • Check fuel pressure.
  • Fix or replace the ignition coil.
  • Clean the fuel filter thoroughly

4. Radiator leaks

The radiator of the Jeep 2.5 engine can leak which can cause further complex issues. This mainly happens if the radiator has cracked due to rusting.  When the car encounters an unsuitable cold or heat, the radiator can leak.

Sometimes, when the head gasket is leaking and the thermostat has a defect, it causes leaking problems in the radiator.


  • Check the radiator.
  • If there is any crack in the radiator, it’s not always necessary to replace that.
  • Attach a radiator flush. This will help with the cracked radiator

5. Sudden shutdown

Inadequate fuel in the tank and Insufficient fuel mixture can cause the sudden shutdown of the engine. Also, if there is a defect in the coolant sensor, rusting of the distributor cap, and low fuel pressure or dead battery, it can cause this problem.


  • Replace the fuel filter
  • Add an injector cleaner.
  • If still, the issue is unsolved, seek professional help.

6. Blinking check engine light

Sometimes happens due to minor or major issues with the engine. But sometimes it may happen even if there is nothing wrong with the engine. Mainly, changes in the humidity are responsible for this.


  • Change the thermostat.
  • Check the Oxygen sensor.
  • Change the spark plug or ignition coil.
  • Tight or replace the loose gas cap.
  • Change the damaged fuel injector.

7. Oil leaks

A crack in the fuel tank and Rusting in the oil gasket cause the oil to leak from the oil tank. Besides, improper or worn-out seals deteriorated valve cover gaskets and loose oil pan drain plugs are also responsible for this.


  • Find the location of the oil leak.
  • Replace the oil pan gasket
  •  You can use an additional oil-stop leak product.
  • Repairing any garage is also inexpensive

8. Failure of exhaust manifold bolt

The manifold bolt goes through continuous tension and compression. So, elastic deformation of the manifold is very common. In this case, the manifold bolt extended to the point that it can’t contract again.

Moreover, bolts are also extended and a Crack in the mounting stud also occurs due to the repeated expansion and contraction. Thus, it’s very usual for exhaust manifold bolts to fail.


  • Replace the old manifold with a new one.
  • Remove and replace the broken or extended bolt

9. Draining of battery

Loose or rusted battery terminals, high heat or extreme cold, and Bad alternators are responsible for this. Mainly, old batteries go through more drainage.


  • Clean and tighten the battery terminals.
  • Protect your car from extreme weather.
  • Check the alternator.
  • Replace the old battery.

10. Transmission issues

Transmission issues occur when the level of transmission fluid is low. Also, it can occur if the transmission filter is clogged.


  • Check the transmission fluid level.
  • Clean the air filter.
  • If still, the problem is unsolved, Change the air filter and fluid of the transmission. transmission

Preventive Methods for Jeep 2.5 Engine Problems

It requires a lot of money to repair the Jeep 2.5 engine problems. But, you can avoid those potential unforeseen issues if you follow some preventive methods. These useful methods are

1. Washing and Waxing

Regular washing and waxing retain the glossy look of the vehicle. Your Jeep 2.5 engine will last for a longer period if you follow this.

Because washing and waxing eliminate the risk of corrosion and rusting of the engine.

2. Changing the oil every 6 months

You need to change the oil depending on your driving habit and the terrain type. Generally, Changing the oil every 6 months is required.

 If you use the vehicle frequently and on rougher terrain, you must change the oil every 10,000 miles.

3. Changing Air Filter Often

The clogged air filter can cause transmission problems and rattling noise in the engine. So, frequent cleaning of the air filter is necessary.

When the air filter becomes damaged, it can cause serious issues in the vehicle. So, frequent change of air filter is mandatory.

4. Timing Belt replacement

The exhaust manifold undergoes continuous contraction and expansion. Thus, elastic deformation occurs often. Thus, If you don’t follow the timing belt replacement routine, it may cause fatal issues in your vehicle.

5. Greasing the fittings

Fittings go through continuous friction. So, those get deteriorated and damaged sooner than any other engine parts. So greasing those fittings is necessary. Because, it will reduce the friction, so the damage due to friction.

6. Changing transmission fluid frequently

Transmission and shifting will develop problems if you don’t change the transmission fluid timely. This fluid deteriorates with time and turns into a dark color.

You have to keep checking the condition of the transmission fluid often. And, if you see the color get darker, change the fluid.

7. Regular inspection

The maintenance manual can require additional maintenance for a particular type of Jeep. So, go through the maintenance manual and keep on regular maintenance and inspection.

If you Check your Vehicle condition regularly, you can identify any issue as soon as it happens. This will reduce the further complexity of the Jeep 2.5 engine problems.


You might be confused about the long discussion of Jeep 2.5 engine problems. Here, we will answer some mostly-asked questions that will eliminate all of your remaining problems.

Does It Mean My Jeep 2.5 Engine Has A Bad Crankshaft If It Makes Bad Noises?

When the Jeep 2.5 engine makes bad noises, people blame the bad crankshaft or the broken valve for this. No. A lousy crankshaft isn’t the prime reason for noise in a Jeep 2.5 engine.

There might be so many clogged galleries. That’s why the valve may be lacking oil. Besides, noises can also occur due to the mere engine tapping.

Is It Wise To Keep Driving Jeep 2.5 Engine Makes Loud Knocking Noise?

If your 2.5 engine makes noises there is no need to change the crankshaft first, as it is very expensive. You can still drive your Jeep with the fluid kept topped up. But it will eat a lot of oil.

Also, the problem may get worse to the point that you will need to replace the engine. Try to fix the issue if you don’t want to do so.


In this article, we tried to uphold some common Jeep 2.5 Engine Problems. So, does that mean this engine is trash? No, it might have several issues, but it serves great durability along with excellent off-road performance.

Thus, we are not discouraging you from buying the engine. Rather, we are just enlightening you about those issues that you may encounter while using.

If you are here from the start, you are already aware of the issues, reasons, and how to resolve those. You can also avoid many fatal engine problems if you take some preventative ways.

As you know the advantages and disadvantages of this engine, you can make the buying decision wisely. Because no engine can assure you service without unforeseen problems.

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