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Diesel Engine Repair & Rebuilds in Harveysburg, OH

Honest diagnostics, real repairs, and full engine rebuilds for Cummins, Power Stroke, and Duramax — serving Warren, Clinton, Greene & Montgomery counties.

Diesel engine repair at County Line Diesel
What We Do

Fix It Right. The First Time.

The fastest way to spend a lot of money on a diesel is to throw parts at a problem nobody actually diagnosed. We don't run that play. Every repair starts with figuring out what's actually wrong. Then we tell you, in plain English, what it'll take to fix it.

From a hard-start no-start to a code that won't clear, from a coolant leak to a complete bottom-end rebuild — we work on diesel engines every day across pickup trucks, commercial rigs, farm equipment, and heavy machinery. If it runs on diesel, we can fix it.

What We Repair

From Small Jobs To Full Rebuilds.

If you're dealing with it, we've probably already fixed it five times this month.

01

Injector Replacement

Bad injectors cause hard starts, rough idle, lost power, and excess smoke. We pull, test, replace, and reset learn values properly.

02

Head Gaskets & Head Work

Coolant in the oil, overheating, white smoke — the head's usually trying to tell you something. We do head gasket jobs and full head work with proper torque procedures.

03

Full Engine Rebuilds

When it's time, it's time. Complete tear-downs and rebuilds with new bearings, gaskets, head studs, and quality machine work where needed.

04

Turbo Repair & Replacement

Turbo's making noise, blowing oil, or just gave up. We diagnose, rebuild, or replace with quality parts — no rebuilt-yesterday auction-lot units.

05

Fuel System Repair

CP3/CP4 issues, lift pump problems, fuel system contamination — we diagnose what failed and what else got taken out with it.

06

Cooling & EGR Systems

Coolant leaks, water pump replacement, EGR cooler failures, radiator and intercooler work. Stop the leak, find the cause.

How It Works

How We Work A Repair.

Repair work runs smoother when there's no surprises. Here's how we move a job from your driveway to fixed.

01

Diagnose

We figure out what's actually wrong — not what the cheapest part to replace would be. Scan tools, gauges, and time on the truck.

02

Estimate

You get a clear write-up: what's broken, what it'll take to fix it, what it costs, and how long it'll be in the shop. No mystery charges.

03

Repair

Work happens in the shop with quality parts. If we find something else along the way, we call before we touch it.

04

Return It Better

Truck goes back fixed and tested. We tell you what to watch for and what's next on the maintenance horizon.

Service Areas

Repair Work Across Four Counties.

Trucks come in from across Southwest Ohio. Click your town below for local info.

FAQs

Repair Questions.

Real answers about how repair work goes here. Anything else, just call.

Do you charge a diagnostic fee?

Yes — diagnostic work is real labor. We charge a diagnostic fee that's typically rolled into the total job if you have us do the repair. That way you're not paying twice for the same time.

How long does a typical repair take?

Depends entirely on what's wrong. Some jobs are same-day (sensor replacements, simple leaks). Some take a week or more (head gaskets, rebuilds). We'll give you a real timeline once we know what we're dealing with.

Do you use OEM parts or aftermarket?

Depends on the job and your preferences. For some repairs, OEM is the only right answer. For others, quality aftermarket performs just as well at a better price. We'll lay out the options before we order anything.

My truck won't start at all. Can you help?

Yes. Diesel no-starts are one of the more common things we work on. Could be batteries, glow plugs, fuel pressure, injectors, or about a dozen other things. We can come look or you can get it towed in.

Do you offer warranties on your work?

Yes — we stand behind the work we do. Warranty terms vary by the repair, but if something we touched isn't right, we make it right. Call us if you've got a specific question.

Truck Down? Let's Fix It.

Call The Shop · Mon–Sat · 8AM–6PM