Common Diesel Issues and Repairs: What Colorado Drivers Should Know
If you drive a diesel here in Colorado, you already know they’re built tough. But tough doesn’t mean problem-free. Diesels need their own kind of care, especially when it comes to emissions testing. At Hinsdale Automotive, we see diesel trucks and cars every day, and a lot of the questions we get from drivers are the same: What happens if my check engine light is on? How long will this take? Do I need an appointment?
Let’s review some of the most common diesel issues we see and explain how the testing and repair process really works so you can feel more confident about what to expect.
The Truth About Check Engine Lights and Emissions Tests
One of the biggest myths out there is that you should fix your check engine light before bringing your vehicle in for testing. The reality? That’s not always the best idea.
Here’s why: imagine your check engine light is on for a transmission issue, and you spend
$5,000 fixing it. Then you come in for emissions, only to fail because of excessive smoke—now you’re staring down another $5,000 repair for an injection pump. That’s $10,000 you weren’t expecting.
By testing with the light on, we can show you the full picture of what’s going on before you commit to repairs. That way, you know all the potential costs and can make a smart decision moving forward.
What Colorado Diesel Testing Looks Like
Diesel emissions testing in Colorado is its own beast, especially around the Denver metro area. If your vehicle is more than seven years old, you’ll need a test every two years. Heavier trucks may have different rules, but for most drivers, here’s what you’re looking at:
- Opacity testing (measuring the amount of smoke from your exhaust) is the big Too much smoke is an automatic fail.
- Check engine lights mean an automatic fail, too, but as we mentioned, the test is still important to see the whole story.
- Repair waivers exist if repairs are too costly, but only after proper testing and
- Retests are required, but here’s the good news: if we do the repairs, the retest is on us at no extra charge.
The goal isn’t just passing the test. It’s making sure your diesel is running cleaner, stronger, and more efficiently.
Pro Tips for Diesel Owners in Colorado
A few simple habits can make a big difference for your diesel here at high altitude:
- Change your fuel filters regularly – our elevation makes clean fuel flow even more
- Always warm up your engine before testing; a cold diesel can smoke
- Stick with quality diesel fuel to cut down on
- Don’t ignore early signs like smoke, rough idling, or sluggish Those little problems tend to snowball.
How Long Does It Take?
The test itself takes about an hour, but we usually ask you to plan on dropping your vehicle off for a bit. That gives us the time we need to run everything properly without rushing the process.
What If My Vehicle Fails?
No one wants to hear “fail,” but if it happens, we’ve got a clear process:
- We’ll schedule a follow-up appointment, or you can just leave your vehicle with us.
- Our team will run a manufacturer-specific inspection to pinpoint the exact problem.
- We’ll walk you through the repair plan, including costs and how long it’ll take.
- If you choose us for the repairs, your retest is free.
We want you to feel informed, not pressured. You’ll always know what’s happening before a wrench is turned.
Common Diesel Issues We See All the Time
Here are the problems that show up most often in our shop:
- Fuel system issues like bad injectors or failing injection pumps
- Excessive smoke caused by worn engine parts or poor combustion
- Sensor failures that confuse your vehicle’s computer
- Exhaust problems, such as clogged filters or faulty EGR valves
None of these are fun, but they’re fixable and catching them early saves money and keeps you on the road.
Quick FAQ for Diesel Drivers
Q: Should I schedule an appointment or just walk in?
A: Scheduling is best. It saves time and avoids waiting around.
Q: Will I fail emissions with a check engine light on?
A: Yes—but testing first gives you the whole picture of what might need fixing.
Q: How long does the test take?
A: About an hour, though we usually ask you to leave the vehicle with us.
Q: What happens if my vehicle fails?
A: We’ll run further tests, explain the repairs, and let you decide next steps.
Q: Do I get a free retest?
A: Absolutely—if we handle the repairs, your retest is free.
At Hinsdale Automotive, we know dealing with emissions tests and diesel repairs isn’t anyone’s idea of fun. But our job is to make it as straightforward, honest, and stress-free as possible. Whether it’s a check engine light, excessive smoke, or just needing your regular diesel test, we’re here to keep you driving with confidence.