Jeep Wrangler Problems (New & Old) – A 2021 Guide

Cory
| Last Updated: May 20, 2021

Clicking.

Grinding. 

Scraping.

These dreaded words can describe a litany of situations that no Jeep owner wants to find themselves dealing with, especially when they’re out on the trail. It’s one thing to encounter an issue from the comfort of your driveway but another whole animal to discover a major issue miles away from civilization and practical help. This is especially true if you’re looking to purchase a Jeep second-hand since you’ll often have no idea what problems the previous owners dealt with. 

So, what can you do? The best thing to have in your arsenal is a guide to the most common problems that plague Jeeps and the best way to take care of these potentially challenging issues. 

Don’t worry, we got your back! Let’s talk about common Jeep Wrangler Problems. 

Jeep Wrangler Issues & Common Fixes

If you’ve ever found yourself on the other end of a persistent issue with your Jeep, you know the challenge of going down rabbit holes that don’t actually end up fixing the problem. Rather than start from scratch,  below you’ll find the most common problems on Jeeps both new and old, and how to fix them. 

So save yourself the hassle and learn from others that have already had the same issues and maybe even learn something new. 

Jeep Wrangler Blinker Problem

The Problem: Blinker (turn signal) light stays on even though the selector is not engaged.

Recommended Fix: Remove the headlight bulb, thoroughly clean connection prongs, and thoroughly reattach the headlight to the base.

Explanation: Over time, the headlight connections on Jeeps can become loose, corroded, or get dirty.

This is the grounding point for the blinkers on Jeeps and a poor headlight connection can cause an intermittent short in the blinker itself.

Fixing the connection will solve the short, which will stop the blinker from randomly turning on. 

Photo credit: JlWranglerForums.com

Jeep Wrangler Starter Problems

The Problem: Jeep will not start when the key is cranked to the start position.

Recommended Fix: Utilizing a voltmeter, start by checking your battery for a proper charge and clean connections, then work your way to the starter (checking for proper voltage at starter solenoid) to determine if the right amount of power is reaching your starter.

Depending on what you discover, you may need to replace the starter but repairing this issue could also be as simple as replacing the battery or cleaning corroded terminals.

Explanation: Many owners assume that the starter is the issue when your Jeep doesn’t, you know, start! However, this is not always the case and replacing a starter is often not necessary.  

Photo credit: WranglerForum.com

Jeep Wrangler Transmission Problems

The Problem: Drivers of certain Jeep models experience a variety of issues including delayed gear shifts, torque converter engagement, and a “limp home” mode that engages in seemingly random conditions.

Recommended Fix: One of the first things to check is the level and quality of transmission fluid since this can cause many of the issues with Jeep Wrangler transmissions. Replacing faulty transmission coolers on certain 5 speed 545RFE units can rectify a problem that allows fluid to leak from the transmission and cause issues. In 4 speed units, replacing faulty solenoids can remedy shifting issues, and replacing broken lockup pumps can fix torque converter engagement issues.

Explanation:  No matter which transmission your running in your Jeep, low or dirty transmission fluid can cause a variety of issues including those listed above.

Specific design flaws in the Mercedes sourced 5-speed unit can cause leaks that will lead to issues with engagement, missed shifts, etc. 4-speed units are particularly prone to issues with torque converter engagement due to a design flaw that allows the lockup pump to break free of its mounts. 

Photo credit: Youcanic.com

Jeep Wrangler Ignition Switch Problems

The Problem: Some owners note that their ignition switch no longer has resistance and will not turn on their Jeep.

Recommended Fix:  Replacing the ignition switch actuator pin should remedy this issue. Here’s a fantastic video that shows how to take care of this issue.

Explanation:  Over time, the ignition switch actuator pin can break within the assembly.

Replacing this small part will save you from having to replace the entire steering column assembly and requires only a few specialized tools and a bit of elbow grease. 

Photo credit: WranglerForum.com

Jeep Wrangler Sway Bar Problems

The Problem: Owners throughout forums across the internet have a serious complaint about the electronic sway bar disconnect suddenly malfunctioning and disconnecting at higher speeds than the system is designed for. This serious issue has caused some Jeep owners to lose control completely!

Recommended Fix: To bypass this design flaw, various companies like Evo Manufacturing make a manual bypass that still allows operation of the sway bar disconnect while bypassing the electronic motor.

Explanation: Some models of Jeep Wrangler utilize an electronic sway bar disconnect that is used at crawling speeds to achieve more articulation in the suspension when off-roading.

Due to poor sealing, this unit can become infiltrated with water and short out. If this happens, the sway bars could be disconnected at road or highway speeds. The sway bar is necessary for safe operation at higher speeds. 

Photo credit: WranglerForum.com

Jeep Wrangler Ignition Coil Problems

The Problem: Some owners of YJ and TJ Jeeps report issues with misfiring on the 4.0 I6, specifically on cylinder #3.

Recommended Fix: Install an ignition wire/fuel injector insulator sleeve on cylinder number 3.

Explanation: After a hot soak (high ambient temperatures, low airflow over engine) increased engine temperatures cause fuel vapor to build in cylinder #3 due to its proximity to the screaming hot exhaust manifold.

Upon restart, this vapor suddenly burns off, causing a misfire and a likely MIL (multi-function indicator light).

Photo credit: YourMechanic.com

Jeep Wrangler AC Problems

The Problem: Although there are several AC complaints from owners, the most common is a lack of cold air coming from the AC system.

Recommended Fix: There are several possible fixes for this issue which range in severity from cheap and easy to expensive and time-consuming:

  1. Replace refrigerant in AC system

  2. Check for blown fuses that cycle AC compressor and accumulator

  3. Check for broken air diversion door (in-dash, selects hot or cold air)

  4. Utilize refrigerant dye to check for leaks in the system

  5. Purchase a manifold pressure gauge to check for low and high side pressure

  6. Replace AC compressor

Explanation: Jeeps, like all vehicles, can encounter issues with the AC system due to leaking coolant, blown compressors, leaking lines, or basically anything in between. This is an advanced troubleshooting process for a home mechanic so you may want to bring in the pros. 

Photo credit: SurvivalTechShop.com

Jeep Wrangler Engine Problems

The Problem: 2012 Pentastar 3.6L engines should be avoided due to pervasive head issues but after 2012, they have been relatively rock solid. The 3.8L is also relatively reliable but it is known to be an oil burner at higher mileage due to poor seals. The 4.0L is well known to be a reliable and solid engine.

Recommended Fix: If you buy 2012 with the Pentastar, be sure to check and see if the heads have been replaced or avoid.

For oil consumption on the 3.8L, switching to a synthetic with a higher viscosity seems to help, as well as changing out the PCV valve. Always monitor oil consumption on the 3.8L! 

Explanation: Every Jeep is a little bit different but it’s best to check these common trouble spots first when purchasing and have your vehicle inspected by a professional to ensure that there are no issues. 

Photo credit: DrivingLine.com

Jeep Wrangler Rust Issues

The Problem: Wrangler, much like any other vehicle that lives in areas where harsh winter weather is a reality, can suffer from rust on the frame. This happens when road salt that’s used to remove snow and ice from the roads impregnates the metal and causes it to degrade.

Recommended Fix: If you already have rust, you’ll need to either tackle the job yourself or let the professionals remove and recondition the rusted spots. This is not an easy fix, so professional help is often needed. 

To prevent rust, you can also utilize a rust-stop spray or coating, which all have various levels of effectiveness. Avoiding driving during winter months and regular, thorough cleanings are also an option to prevent rust.

Explanation: Rust on vehicles is not unique to Jeeps! If you live in an area with inclement winter weather, you’re bound to have issues with rust if you don’t properly keep on top of it. Prevention is key here because once you have it, it’s very tough to remedy. 

Photo credit: Jeepz.com

Jeep Wrangler Acceleration Problems

The Problem: Owners of certain Jeep Wranglers report a sudden loss of acceleration or a delayed response to accelerator pedal inputs. 

Recommended Fix: Common trouble spots on Jeeps are failed 02 sensors, dirty throttle bodies, clogged air filter, stretched throttle cables, or a failed Governor Pressure Sensor.

Explanation: Issues with acceleration typically stem from either a physical lack of air or fuel (via clogged filters, throttle body, injectors, etc.) or from a sensor that thinks there is a lack of air or fuel. Tracking down these issues should always start with these components. 

Photo credit: MotorBiscuit.com

Jeep Wrangler Idle Problems

The Problem: Owners of Wranglers may encounter a rough idle, a stuttering, or an idle speed that is higher than factory specifications. 

Recommended Fix: If you’re dealing with a rough idle, the likely culprit is a dirty throttle body. A higher idle speed is typically the result of a large vacuum leak, while a low idle speed could be due to a dirty throttle body or malfunction throttle position sensor.

Explanation: Proper airflow, vacuum, and throttle position are required for any engine to maintain proper idle speed. Any issues with these components can lead to problems with idle.  

Photo credit: CarCareTotal.com

Jeep Wrangler Traction Control Problems

The Problem: Traction control can suddenly activate while driving causing a troubling reduction in acceleration or rapid braking. This is especially common after a lift or after driving on a lift for some time. 

Recommended Fix: You’ll need to ensure that the alignment in your Jeep is spot-on, especially after installing a lift. Additionally, broken ABS sensors or mud cakes within your wheels can also cause issues with traction control.

Explanation: Traction control works by monitoring your wheel speed and position. Once predefined limits are exceeded, the system activates to get the vehicle back within parameters. Lifting your Jeep can change these baseline parameters and cause your system to think that the wheels are out of sorts when they’re not. Similarly, debris in the wheels and broken sensors can also cause this issue. 

Photo credit: JlWranglerForums.com

Conclusion 

All in all, Jeeps are relatively reliable and easy to work on but like any good thing, they are not without their issues. Having some basic working knowledge of common problems on the Wrangler can help you head off issues before they leave you stranded and help you avoid the domino effect of problems that stack on top of each other. Whether you own a Jeep already or are looking to join the Jeep family, knowing your vehicle well will lead to a positive ownership experience. 

People Also Ask

Here’s a question that gets asked over and over:

What Years are the Worst for Rust Issues on Jeep Wrangler?

Although there is no universal consensus, the TJ Wrangler (1997 – 2006) seems to be especially rust challenged, especially in the early years.

Who Worked on This?


Brian

Editor

A master of organization, Brian helps keep everything running smoothly for Your Jeep Guide.

No Jeep yet but we’re working on that!

Cory

Writer

Cory loves his XJ and frequently thrashes it through the hills. He’s constantly fixing something.


“What fenders?”

Check Us Out!