Hummer H3: Bad Coil Packs → Symptoms and Diagnosis

  Bad Coil Packs are one of the more problematic ignition issues that can occur with the Hummer H3.  A bad oil pack can make your H3 almost un-drivable.  Or it may have little effect at all on the engine’s ability to run.  It’ll get worse as they lose their ability to fire the spark plugs. … Read more

Hummer H3 Not Starting: Causes + How to Fix

If your Hummer H3 doesn’t start, you’ve found the right article.  Many different issues can cause the problem.  We cover all the likely ones in an order that makes sense when diagnosing the issue at home. This article is written with the assumption that you are looking for a way to get your Hummer H3 … Read more

Hummer H3 Bad Fuel Pump: Symptoms, Causes, + Diagnosis

A bad fuel pump can cause a myriad of problems for your Hummer H3, making it essential to be aware of the warning signs that indicate trouble. Your fuel pump is responsible for pushing fuel from your vehicle’s fuel tank to the engine, but when it starts to fail, your engine may suffer run rough, … Read more

Hummer H3: Bad Alternator → Symptoms & Diagnosis

A bad alternator can leave your Hummer H3 without power and unable to move.  Alternators don’t always go bad in the exact same way.  We’ll cover the symptoms of when an alternator goes bad, and how to diagnose a bad one (which is really pretty easy).   How Your H3’s Alternator Works The alternator’s job … Read more

Hummer H3 Bad Fuel Filter: Symptoms, Causes, Hot to Fix

A bad fuel filter is one of the worst problems that can happen to your Hummer H3.  When the filter fails, it can limit the amount of fuel that enters the engine.   Without proper fuel pressure, your vehicle will not run at all.  With that in mind, most of the symptoms of a bad fuel filter revolve … Read more

Hummer H3 Bad Spark Plugs: Symptoms, Diagnosis, + How to Fix

An engine functions as a pump, requiring a precise combination of fuel, air, and spark. If any element of this trio is imbalanced, your Hummer H3 won’t run right (or at all). While a misfire is the symptom of bad spark plugs, bad spark plugs almost always indicate a problem with the engine (more on … Read more

Hummer H3 Bad Oxygen Sensor: Symptoms and Diagnosis + How to Fix

Oxygen sensors play a crucial role in your Hummer H3’s emissions system and fuel management. These sensors detect the levels of oxygen present in the exhaust, which is a primary component in maintaining the optimal air-fuel ratio. A damaged or faulty oxygen sensor can have a significant impact on your vehicle’s overall performance, making it … Read more

Hummer H3 Low Oil Pressure: Diagnosis and Causes

One of the most serious issues that can happen to your Hummer H3‘s engine is if it ends up with low oil pressure.  Low oil pressure will cause the engine to seize up.  When the oil pressure light on, it should be assumed that the engine locking up is imminent. We advise not running the … Read more

Hummer H3 Blown Head Gasket: Symptoms, Causes, How to Fix

One of the most common (and) critical major engine problems is a blown head gasket. If your Hummer H3 has blown a head gasket, you may find it running poorly or not at all.  Below you’ll find the symptoms, causes, and price of a Hummer H3 head gasket. Recognizing the signs of a blown head gasket in your … Read more

Hummer-H3 Catalytic Converter: Price, Location, and Diagnosis

Your Hummer H3 leaves the factory with a catalytic converter.  It can run into problems over the normal life of the vehicle, and is often accompanied by OBDII code P0420.  Below we’ll cover the location, price, and symptoms of a bad torque converter in your H3.   Menu: Catalytic Converter Price H3 Catalytic Converter Location … Read more