Mobile Diesel Engine Repair & Aftertreatment Service
Overheats, fuel problems, leaks, DPF/DEF headaches — engine work at your yard on Cummins, Detroit, PACCAR and more.
Engine trouble doesn't always mean an engine job. Overheating is usually a cooling-system failure; hard starts are usually fuel or air; a shaking idle is often one injector talking. Ronin Mechanical diagnoses engine problems at your truck anywhere south of Duncan and fixes what's actually broken — on Cummins, Detroit, PACCAR MX, Volvo, Mack and Navistar power.
A large share of "engine" calls we see are cooling and fuel systems: hoses, thermostats, water pumps, fan clutches, filters, priming problems and leaks — all textbook mobile repairs. Aftertreatment is its own animal: DPF, DEF/SCR and EGR faults that trigger derates and ruin schedules. We diagnose those honestly and tell you what's fixable on site, what needs cleaning or replacement parts, and what the fastest legitimate path back to full power is.
What we handle on-site
- Overheating — thermostats, water pumps, fans, hoses, radiators
- Fuel system repairs — filters, lift pumps, priming, leaks, contamination
- Belts, tensioners and accessory drive repairs
- Oil, coolant and fuel leak diagnosis and repair
- DPF/DEF/EGR fault diagnosis, sensors and regens where appropriate
- Injector and hard-start diagnosis
- Valve adjustments and scheduled engine services at your yard
Straight answers on big repairs
When a diagnosis points at something major — an injector cup, a head gasket, an EGR cooler — you get the evidence, the options and honest numbers before anything comes apart. Some jobs make sense mobile at your yard over a day; a few genuinely belong in a shop, and we'll say so rather than start something the roadside can't finish. Either way you keep control: it's your truck, your schedule, and a $130/hour clock with parts at supplier cost.
If the engine light is on but the truck still runs, start with a mobile diagnostic visit — twenty minutes of scanning at your yard beats a tow you might not have needed.
Related services
Book a mechanic — by text
Fastest: the wizard builds a clean dispatch text with your issue, truck and location, and copies you on it.
Start the 60-second bookingOr text us directly:
Prefer voice? Call the same number. 24/7 emergency roadside + scheduled maintenance by appointment.
- $130/hour — around the clock
- Zero markup on parts (receipts included)
- No call-out fee, no zone fees
- Estimate our travel time
Diesel Engine Repair — FAQs
My truck is overheating on the Malahat climb. What now?
Pull into a brake-check or viewpoint pullout, leave the engine idling if it's safe (shutting a hot engine off hard can make things worse), and watch the gauge. If it won't come down, shut down and text 250-974-7899 with your location. Malahat overheats are one of our most common calls — usually a fan clutch, thermostat, or coolant loss we can fix at the pullout.
Can you fix DPF and DEF problems on site?
Often, yes. Failed sensors, DEF quality faults, dosing issues and stuck soot levels can frequently be diagnosed and repaired at your truck, including forced regens where the system supports it and the situation warrants it. Severely plugged filters may need off-truck cleaning — if that's the case, we'll confirm it with data first so you're not paying for guesswork.
Do you work on both the truck and its attached equipment?
Yes. Truck engines, PTO-driven systems, and the diesel power on attached and mounted equipment are all in scope — one visit, one invoice. For excavators, loaders and other machines, see heavy equipment repair.
How do parts work on engine repairs?
We source from the dealer or supplier that has your part soonest — Langford, Saanichton or up-island when needed — and you pay exactly the counter price, with the receipt attached to your invoice. On a booking you can even add a parts-stop address so the mechanic collects a part you've already arranged on the way to you.
Truck down? Text us your location.
A real dispatcher replies fast — you and dispatch both get the booking by text. 24/7 emergency roadside + scheduled maintenance by appointment.