The Colorado is Chevrolet’s midsize pickup truck. In 2004, General Motors introduced the Colorado nameplate to replace the Chevy S10. Over the years, the first-generation (2004-2012) Chevy Colorado has proven itself a reliable and efficient compact truck. But no vehicle is without its issues. Luckily, the mechanics at 1A Auto have compiled a list of the top issues you may encounter in a Chevrolet Colorado.

• A check engine light caused by worn valve seats
• Heat and A/C problems caused by a bad blower motor or resistor
• A check-engine light caused by a stuck EVAP vent valve
• Running out of fuel early due to a malfunctioning gas tank level sensor

Worn valve seats causing a check engine light

When my colleague Nathanial Ehringer reported on the most common Chevy Colorado problems reported by owners, worn valve seats made the list. The valves in the engine’s cylinder head open and close as the engine rotates. During the combustion cycle, it is the action of these valves that fill each cylinder with fresh air, then release the resulting gas into the exhaust.

An engine’s valves must not only open and close rapidly, but they must seal completely. For this reason, they snap shut on a donut-shaped “valve seat.” These gaskets always wear out eventually. But in specific Chevy Colorado engines, they are notorious for wearing out prematurely. Worn valve seats will cause your Chevrolet Colorado to run roughly. You should also see a solid or flashing check engine light.

Unfortunately, if worn valve seats are causing a check engine light, you’ll likely need to replace the entire head of your Chevy Colorado’s engine. It’s no wonder that the experts at 1A Auto named this one of the truck’s top issues in their Chevy Colorado guide.

Heat and A/C issues due to a bad blower motor or resistor

When Chevrolet Colorado owners reported issues with their trucks, a failed HVAC fan was their most common complaint. This could be a very uncomfortable and frustrating problem to deal with. In certain weather, not having defrost could even be a serious safety concern. Luckily, there might be a relatively simple solution.

When you select different HVAC fan speeds, your Chevrolet Colorado uses an electrical component called a “resistor” to limit electricity flowing into the blower motor and adjust its speed. The blower motor resistor on first-gen Colorados tends to fail prematurely, preventing you from turning on your HVAC fan.

The resistor is plugged in beneath your glove box and is thus a relatively easy electrical component to replace. But before you swap it out yourself, you’ll want an automotive technician to test the blower motor itself. This is because the cause of that resistor failure is often a bad blower motor that is drawing too much electricity.

Check-engine light from a stuck EVAP vent valve

There’s a second common reason that Chevrolet Colorado pickup trucks throw a check engine light, and you’ll be relieved to hear you can fix it without replacing the engine head. This is because the Colorado’s gas tank has a system designed to recover escaped gasoline vapors and burn them in the engine. This EVAP system is important for both fuel efficiency and emissions.

If you have a check engine light, but your truck is still running fine, it may be your EVAP system. The cause could be some debris stuck in the valve that releases pressure from this EVAP circuit into the air. Or it could be even simpler, it could just be a gas cap that isn’t sealing properly.

The first thing you can do is to make certain your gas cap is screwed on tightly. Then restart your truck and see if the problem goes away. Next, have an automotive technician–either at a shop or an auto parts store–read your check engine light. Once you have a bit more information on what is causing the light you can plan how to fix it.

Next, find out whether midsize pickups are actually cheaper than full-size trucks or watch a mechanic review the top 2004-2012 Chevy Colorado issues in the 1A Auto video below: