I work on a lot of diesel trucks across the GTA — Ram 2500s, F-250 Super Dutys, GMC Sierra 2500HDs — and the pattern I see over and over is the same. Owners are good about engine oil. Sometimes they remember the fuel filter. But the DPF, the CCV filter, the second fuel filter on dual-filter setups? Those get ignored until something breaks expensively.
This isn't shade — diesels are genuinely more complex than gas engines, and the maintenance schedules aren't as well-known. But skipping this stuff leads to $3,000–$8,000 repair bills that could've been avoided for a few hundred dollars of regular service. Let me break down what actually matters.
The Diesel Particulate Filter (DPF) captures soot from the exhaust. It's been required on diesel vehicles in Ontario since the mid-2000s, and it's the component most diesel owners know the least about.
The DPF cleans itself through a process called regeneration — it gets hot enough to burn off the accumulated soot. This happens automatically when conditions are right: sustained highway driving, engine up to temperature, load on the engine. The computer triggers it, exhaust temps spike, soot burns off. You might notice increased idle RPM, a slight smell, or a brief drop in fuel economy. That's normal.
The problem: if you spend most of your time in short trips, city driving, or stop-and-go (which describes a lot of GTA commercial use), the passive regen can't complete. Soot builds up. Eventually the truck tries an active regen and can't complete that either. Now you've got a partially or fully clogged DPF, and your truck is in limp mode.
A forced regen — done with a scan tool while the truck is running — can sometimes clear a partially clogged DPF. A fully clogged filter needs cleaning (chemical soak or bake-and-blast) or replacement. Replacement on an F-250 6.7 Powerstroke or Ram 2500 6.7 Cummins can run $2,000–$5,000 at a shop. Maintaining it properly costs a fraction of that.
The Crankcase Ventilation (CCV) filter — sometimes called the oil separator — is on the Ram 6.7 Cummins and manages crankcase pressure. It filters blow-by gases from the engine before they're recirculated into the intake. When it clogs, crankcase pressure builds. Excessive crankcase pressure causes oil leaks — rear main seals, valve cover gaskets, front crankshaft seals. It can even collapse air intake tubes.
Cummins specifies CCV filter replacement every 67,500 km under normal conditions. Most owners I see have never changed it. The filter itself is about $60–80. The repairs you'll do instead of changing it can run $500–$1,500+.
On the 6.7 Power Stroke (F-250/F-350), the equivalent is the oil separator on the crankcase ventilation system — same principle, same neglect pattern. On GM's Duramax, it's the CCV system on the engine valley. Different locations, same idea.
Most modern diesel trucks run two fuel filters — a primary (water separator/pre-filter) and a secondary (main filter). The GMC Sierra 2500HD with the 6.6 Duramax has them. The Ram 2500 Cummins has them. The Ford Super Duty 6.7 Powerstroke has them.
A lot of owners know about one filter. Some don't know there's a second one. And some replace only one and consider the job done.
Fuel filter intervals on diesel trucks are typically every 30,000–40,000 km, but in Ontario that shortens if you're running off-road diesel, biodiesel blends, or fuel from sources with variable quality. Restricted fuel filters cause hard starting, power loss under load, rough running, and eventually fuel pump failure. Injectors are the catastrophic end of that chain — diesel injector replacements run $300–$600 each and there are 6–8 of them.
| Service | GTA Shop (typical) | Mobile (Cars With Fares) |
|---|---|---|
| Diesel oil change (incl. filter) | $150–$250 | $120–$180 |
| Dual fuel filter replacement | $180–$300 | $150–$240 |
| CCV filter replacement (Cummins) | $100–$180 | $80–$140 |
| Forced DPF regen (scan tool) | $120–$200 | $100–$150 |
| Full service package (oil + both fuel filters + CCV) | $400–$650 | $320–$500 |
The cost difference is real but not the main point. The main point is that mobile service means I come to your yard, your jobsite, or your driveway — the truck doesn't need to be taken off duty to go to a shop. For commercial trucks or fleet vehicles, that matters.
If you're running a Ram 2500/3500 Cummins, Ford F-250/F-350 Super Duty, or GMC Sierra 2500HD in the GTA — especially in a commercial capacity — here's the service schedule I tell my customers to follow:
These aren't big jobs. Done proactively, they cost a few hundred dollars a year. Ignored, they create $3,000–$8,000 failures at the worst possible times. Call or text me at 647-450-0406 and I'll come to your truck, wherever it is in the GTA, and get it on the right maintenance schedule.
Call or text for mobile diesel service — oil changes, fuel filters, DPF service, and more at your location.
Call 647-450-0406