Diesel & Engine Repair

Your engine is the most expensive thing on the truck to get wrong — which is exactly why guessing costs you so much. When a shop swaps parts on a hunch, you pay for the wrong fix and the breakdown that follows. J&A Fleet doesn’t work that way. We run real diagnostics, find the root of the problem, and fix that — whether it’s a sensor, a fuel issue, or a tired engine that needs a rebuild. Caterpillar Level 2 certified techs, mobile when the job allows, in the shop when it needs the bay.

WHAT WE DIAGNOSE AND REPAIR

• Hard starts, no-starts, and rough running
• Power loss, derates, and limp-mode faults
• Check-engine and warning lights — read, traced, and explained
• Fuel system problems — injectors, pumps, lines, and water-in-fuel
• Turbo and boost issues
• Aftertreatment and emissions — DPF, DEF, and regen faults
• Coolant and oil leaks, overheating tied to engine condition
• Major work — head gaskets, in-frame and out-of-frame rebuilds, and full engine replacement

HOW WE DIAGNOSE — AND WHY IT SAVES YOU MONEY

A warning light is a starting point, not an answer. We confirm the actual fault before we quote a repair, because the codes don’t always tell the whole story. If we can’t recreate the problem, we keep digging — we won’t bill you for parts that “might” fix it. When we know what’s wrong, we tell you what it’ll take, what it’ll cost, and whether the repair is even worth it on that truck. That honest call has saved customers from dumping money into a unit that wasn’t worth saving — and saved others thousands over what another shop wanted for a part they didn’t need.

DONE RIGHT THE FIRST TIME

Our techs are trained on heavy-duty diesel and certified to work on it. We use quality parts, torque to spec, and verify the fix before the truck leaves — because a comeback costs you another day down, and that’s the opposite of the point. Whether it’s a quick diagnostic or a full overhaul, the standard is the same: fixed right, once.

PRICING YOU CAN SEE COMING

You’ll hear our hourly rate, our minimum, and any surcharges up front. Mobile road service is billed port to port — from when we leave the shop to when we return — and the price only changes if the job changes. No padded estimates, no surprise line items.

MOBILE OR IN THE SHOP

A lot of diesel work can be handled on site, and we’ll come to you for it. For bigger jobs — rebuilds, replacements, anything needing the bay — we don’t run recovery vehicles, but we work with a network of recovery partners and get the best rates to bring your truck in, then handle the repair once it’s here.

WHERE WE WORK

Diesel and engine repair across Morris, Aurora, Joliet, New Lenox, Rockdale, Gardner, and the surrounding I-80 / I-55 corridor.

What Our Customer Says

Went to a chain that wanted over $3,000 for a part we didn’t need. J&A found the actual problem and had us ready to go in under an hour. Very honest shop.

WHY Choose J&A Fleet

Founded by a diesel tech who became a fleet manager and got tired of watching shops sell labor instead of fixing trucks. That’s the whole reason J&A exists — honest diagnosis, fair pricing, and engine work that holds up.

Engine acting up?

Don’t wait for it to strand you. Call J&A Fleet at (815) 518-5252 for diesel and engine repair done right.