Hummer H2 Reliability and Common Problems

Lisa Conant, Automotive Features Reviewer at CarParts.com

Reviewed by

Lisa Conant, Automotive Content Specialist

Automotive Features Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on October 27th, 2024

Reading Time: 5 minutes
Summary
  • The Hummer H2 has decent reliability, With J.D. Power giving the 2009 model a score of 3 out of 5.
  • The Hummer H2 has been known to develop problems like mode door actuator failure, gas cap issues, low oil pressure, and engine stalling, among other things.
  • You should do your research and carefully inspect the vehicle you intend to buy to minimize risk. You can maximize your Hummer’s service life by replacing bad parts immediately.

If you’re looking for a large SUV that’s built tough, you can’t go wrong with a Hummer H2. It’s best known for its excellent off-road capability, superb engine performance, and distinct design. If you’re planning to buy a used Hummer H2, it’s a good idea to read up on its reliability ratings and research the common issues it may develop as it racks up mileage.

Is a Hummer H2 Reliable?

The Hummer H2 has a good reputation in terms of reliability. Kelley Blue Book gave the 2005 model a 4.7 reliability score based on consumer reviews, while J.D. Power gave the 2009 model a score of 3 out of 5.

Hummers are built for rough terrains and extreme weather conditions. As long as you follow your regular maintenance schedule and replace faulty parts immediately, your H2 can run for 300,000 to 500,000 miles without needing any major repairs.

Hummer H2 Common Problems

No matter how tough your Hummer is, it is bound to need some repairs as it gets older. Here are some of the issues your H2 may develop over time:

Mode Door Actuator Failure

Mode door actuator failure is a widely reported issue for 2003-2009 Hummer H2s. If left unresolved, it can cause improper HVAC (heating, ventilation, air conditioning) temperature and air delivery. Many owners of the affected units had to spend around $50 to $70 on diagnosis alone to address the problem.

Gas Cap Issues

A loose or worn gas cap is a common complaint for the 2003-2009 model years. The check engine light usually illuminates to mark this issue.

However, a gas cap problem is not the only issue that can activate the check engine light. So if you encounter this symptom, it’s best to take your vehicle to your mechanic for proper diagnosis. Here’s a guide on how to tell if your gas cap is the one triggering your H2’s check engine light.

Low Oil Pressure

Some 2006 Hummer H2 owners have reported loud knocking sounds along with coolant loss. Image source: Wikimedia.

Problems with oil pressure were among the top complaints for the 2006 model year. Repairs for this type of problem can reach up to $7,000.

Many 2006 Hummer H2 owners reported loud knocking sounds along with coolant loss. Most of them replaced their oil pump to solve the issue, but, in most cases, the problem persisted. Some drivers unfortunately had to get their engine replaced in order to fix the issue.

Engine Stalling

Some 2003-2006 Hummer H2 owners have complained that their SUV is prone to engine stalling and low idle speed. Servicing the throttle body usually corrected the issue. Throttle body cleaning usually costs anywhere between $230 to $290.

If you encounter this problem with your Hummer, note that many underlying issues can cause your H2 to stall. So it’s best to take your vehicle to an auto repair shop for proper diagnosis.

Steering Wheel Position Sensor Failure

A steering wheel position sensor that failed after around 58,000 miles is another common complaint among many H2 owners. A service stability message usually accompanies this issue.

The steering wheel position sensor or steering angle sensor (SAS) plays a crucial role in ensuring predictable steering. If it’s faulty or worn out, it can cause problems like loss of steering control. Fortunately, there’s no shortage of aftermarket steering wheel position sensors available today, so you can easily order one for your H2 if you encounter this issue.

Faulty Turn Signal Switch

Several owners of 2003-2006 H2s have complained about hearing clicking noises coming from their vehicle’s turn signal flasher when the turn signals are switched off. Upon inspection, mechanics found a fault in the turn signal switch.

Fortunately, replacing the faulty switch usually resolves this problem. Parts may cost you anywhere between $40 and $120. Labor costs may set you back by another $80 to $100.

Restricted Secondary Air Injection Valve

Some 2003-2006 Hummer H2s can develop faults in their air injection valves. Image source: Wikimedia.

Some 2003-2006 Hummer H2s can develop faults in their air injection valves. The secondary air injection valves on these vehicles may be restricted, resulting in poor air flow.

An illuminated check engine light is usually the first sign that there’s something wrong with these valves. Mechanics recommend replacing both valves at the same time, even if only one valve is faulty.

Fuel Level Sensor Failure

Several 2003-2004 Hummer H2 owners have also complained about fuel level sensor malfunction. Their faulty sensor recorded incorrect fuel tank level readings, resulting in erratic fuel gauge behavior. Most of them noticed that their gauge read “full” then “empty” again in a short span of time. Some drivers also noticed changes in their usual gas mileage.

These are only some of the issues your Hummer may develop as it puts on the years. By doing your research and carefully inspecting the vehicle you intend to purchase, getting this SUV should come with little risk. More importantly, you can maximize your Hummer’s service life by following its maintenance schedule and replacing faulty or worn-out parts immediately.

Hummer H2 Years to Avoid

The Hummer H2 years you should avoid are the 2003, 2004, and 2006 models.

2003 Hummer H2

The 2003 Hummer H2 had its share of issues, mainly because it was the first production year. Some problems that hampered this year include premature tire wear and accessory belt tensioner failure.

Tire wear is a safety hazard, as you may lose control on the road. If you drive this model year, make it a habit to check tire alignment and rotate it properly.

A failing belt tensioner will cause the belt to slip, causing accelerated wear on belt-driven accessories. Regularly inspect the accessory belt tensioner to prevent breakdowns.

2004 Hummer H2

Unfortunately, the second iteration of the H2 had similar problems to the 2003 model. In addition to tire wear and belt issues, the 2004 H2 reportedly had issues with its air suspension system.

To make sure that your suspension system stays in tip-top shape, it’s best to take your vehicle to a mechanic for professional advice.

2006 Hummer H2

Lastly, 2006 is arguably the worst year for the H2. It had major causes of concern, such as knocking noises and coolant loss caused by oil pressure problems. Avoid this model year if you don’t want to spend on costly repairs and deal with potential engine damage.

Getting Your Hands on Replacement Parts for Your Hummer H2

Though there’s no denying that the Hummer H2 is a reliable off-road SUV, it can develop issues as it racks up mileage. Problems like gas cap issues and stalling engines aren’t unheard of, meaning you’ll need to get parts repaired or replaced every now and then.

Luckily, you can get replacement parts for your Hummer easily when you shop at CarParts.com.

The best part? You don’t even have to leave your home to get parts that fit your ride. Visit our website using your mobile device or computer, fill out our vehicle selector, and adjust the filters. With just a few clicks, you can find exactly what you need to restore your Hummer’s top-notch performance.

We source our components from the most reliable names in the industry to ensure they’re built to last. On top of that, our warehouses are located all over the US, meaning you can receive your order in as fast as two business days.

Shop now and take advantage of our competitive prices!

About The Authors
Reviewed By Lisa Conant

Automotive Features Reviewer at CarParts.com

Lisa Conant grew up in Canada around a solid contingency of gear heads and DIY motor enthusiasts. She is an eclectic writer with a varied repertoire in the automotive industry, including research pieces with a focus on daily drivers and recreational vehicles. Lisa has written for Car Bibles and The Drive.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

View Comments

  • Hummer h2 SUT are timeless and the values are holding strong! These want last long in the market place!

  • My 2009 Hummer H2 is great, only 3500 miles on it just replaced the motor with a new l9h and a Magnuson supercharger, tranny & xfer case also re-man'd, kryptonite front end suspension