Exhaust Smell Or Fumes In The Cab
Fumes in the cab mean exhaust is escaping ahead of the stack. That is a leak to find right away, not one to live with.
Checked:ManifoldFlex pipeClamps
Repair now
Heavy-duty exhaust · Louisville, KY
Heavy-Duty ExhaustSystem Repair.
Exhaust leaks, clogged diesel particulate filters and SCR catalyst problems, found and fixed. Superior Truck & Trailer repairs exhaust systems on heavy-duty trucks and fleets in Louisville, KY, with high quality parts and the equipment to diagnose what the truck is actually doing.
- Exhaust LeaksManifolds, clamps, pipes
- DPF IssuesA filter that clogs
- SCR CatalystNOx, DEF and sensors
Three kinds of exhaust work
Leaks, DPF And SCR.
A heavy-duty exhaust from the turbo to the stack, with the gas running through it: where it leaks, where the soot stops, and where the NOx gets cleaned.
Exhaust Leak Repair
Leaks are one of the most common exhaust problems. They cost fuel, raise emissions and can damage other parts of the truck. The leak gets found and repaired with high quality parts.
Diesel Particulate Filter Issues
The DPF removes particulate matter from the exhaust. Over time it can clog, which costs power, raises emissions and can damage the engine. DPF issues get diagnosed and repaired.
SCR Catalyst Issues
The SCR catalyst reduces nitrogen oxide emissions. When it malfunctions, emissions rise, fuel economy drops and the engine can be damaged. SCR problems get diagnosed and repaired.
Exhaust leak checklist
Manifold and turbo: what gets checked
- Soot tracks at the manifold gaskets
- Cracks in the manifold
- Broken or loose studs
- Turbo inlet and outlet flanges
- Ticking at a cold start
- Heat damage to wiring nearby
Flex pipe and clamps: what gets checked
- Cracks in the flex bellows
- V-band clamps seated and tight
- Band clamps and overlaps
- Soot at every joint
- Pipe alignment into the joint
- Movement with the engine
Pipes and hangers: what gets checked
- Rust-through and pinholes
- Cracks at welds and bends
- Hangers and isolators
- Pipe rubbing the frame
- Stack and tailpipe mounts
- Fumes getting into the cab
DPF checklist
Soot load: what gets checked
- Pressure across the filter
- Soot load on the scan tool
- DPF and regen lamps and codes
- Exhaust temperature sensors
- Why it is making soot
- Leaks ahead of the filter
Regeneration: what gets checked
- Regen history and how often
- Regens that start and stop
- Doser and DOC light-off
- Exhaust temperatures during regen
- Forced regen, where it fits
- Idle time and short trips
Ash: what gets checked
- Pressure after a full regen
- Miles and hours on the filter
- Ash cleaning or a replacement
- The face of the DOC
- Oil getting into the exhaust
- Cracked or melted substrate
SCR checklist
DEF dosing: what gets checked
- DEF quality and concentration
- Doser nozzle and crystals
- DEF pump, filter and lines
- Line and tank heaters
- Dosing rate against the demand
- DEF level and tank sensor
The catalyst: what gets checked
- Conversion efficiency codes
- Deposits from DEF
- Exhaust temperature across it
- Damage or contamination
- Leaks before the catalyst
- Derate history
NOx sensors: what gets checked
- NOx reading before the SCR
- NOx reading after the SCR
- Sensor wiring and connectors
- Heater circuit faults
- Readings that disagree
- Codes and freeze-frame data
The exhaust, part by part
Manifolds & GasketsCracked manifolds, blown gaskets, broken studs.
Flex Pipe & ClampsCracked bellows, loose V-band and band clamps.
Pipes, Stacks & HangersRust-through, cracks and hangers that let go.
Diesel Particulate FilterClogging, regeneration and ash, diagnosed and repaired.
SCR Catalyst & DEFThe catalyst, the doser and the DEF supply.
Exhaust SensorsNOx, temperature and pressure sensors and wiring.
Related repairs and services
EGR & DPFThe EGR system and the DPF, in depth.Engine Repair, Rebuild & ConversionWhen soot or oil in the exhaust starts at the engine.Diagnostics & Electrical RepairSensor codes, wiring and the scan tool.General Diesel RepairDiesel repair across the whole truck.Welding & FabricationBrackets, hangers and custom exhaust work.24/7 Mobile & Roadside AssistanceA derate on the interstate, any hour.
What drivers notice first
Signs It Needs Exhaust Work.
Where each one usually leads. Caught early, a leak is a gasket and a clogged filter is a cleaning, not an engine repair.
Ticking That Fades As It Warms
A tick at a cold start that goes quiet once the engine warms up is the classic sign of a manifold gasket or cracked manifold.
Checked:Manifold gasketStudsTurbo flange
Often a gasket
DPF Light Or Regens More Often
A DPF lamp, or regens that come more and more often, mean the filter is loading up faster than it can burn clean.
Checked:Soot loadRegen historyPressure sensor
Diagnose soon
Loss Of Power Or A Derate
A clogged DPF or an SCR fault can drop the truck into a derate, with the speed held down until the problem gets fixed.
Checked:DPFSCRNOx sensors
Diagnose now
DEF Warnings Or DEF Use Off
DEF that barely goes down, or goes down too fast, and DEF warnings point at the doser, the pump, the lines or the DEF itself.
Checked:DoserDEF pumpDEF quality
Often a repair
Black Soot Tracks Or Smoke
Black streaks around a joint or clamp show exactly where it leaks. Black smoke out the stack points at the engine or the DPF.
Checked:JointsDPFEngine
Find the cause
Exhaust work
From The Joints To The Filters.
Exhaust work runs from the manifold at the engine to the stack, with the filter and the catalyst in between.
How exhaust work moves through the shop
From the first call to a clean-running exhaust.
Tell us the truck and what it is doing. We check the exhaust and pull the codes, lay out the repair, do the work and get the truck back into service.
01You call
Tell us the truck, the codes on the dash and what it is doing: the smell, the noise, the derate.
02We check it
The exhaust gets checked end to end, and the codes and sensor readings get pulled.
03You approve it
The leak, the filter or the SCR fix, laid out up front. Nothing gets done until you approve it.
04You roll
The repair gets done, the codes get cleared and checked, and the truck goes back to work.
Working trucks, real shop work
The work happens here, on the road and in the bay.
The trucks, trailers, service vehicles, roadside calls and shop work behind the services on this site. This is the kind of commercial equipment Superior works on every day in and around Louisville.
Truck repair customer reviews
What Drivers SayAbout The Shop.
Read customer feedback on Superior Truck & Trailer's repair work, communication, and service experience in Louisville.
Exhaust work backed by a full truck shop
The Rest Of The Truck,Same Shop.
Exhaust problems often start somewhere else on the truck. Everything else it needs is handled from the same Louisville shop.
Exhaust repair FAQ · Louisville, KY
Truck Exhaust Questions.
Leaks, DPFs, SCR catalysts and DEF: the exhaust questions truck owners and fleets ask most.
(502) 789-6644What does exhaust system repair on a heavy-duty truck include?
At Superior Truck & Trailer it covers the three most common exhaust problems: finding and repairing exhaust leaks, diagnosing and repairing diesel particulate filter (DPF) issues, and diagnosing and repairing SCR catalyst issues.
What problems does an exhaust leak cause?
Exhaust leaks can decrease fuel efficiency, increase emissions and even damage other parts of the truck. A leak near the cab can also let fumes inside, which is a safety problem.
How do I know my truck has an exhaust leak?
Common signs are an exhaust smell or fumes in the cab, a ticking noise at a cold start that fades as the engine warms, black soot tracks around a joint or clamp, and a louder exhaust note.
What does a diesel particulate filter do?
The DPF removes particulate matter, the soot in diesel exhaust, before the exhaust is released into the air. It traps the soot and burns it off during regeneration.
Why does a DPF clog?
Over time a DPF can clog with soot that is not burning off and with ash that regeneration cannot remove. A clogged DPF can reduce performance, increase emissions and even damage the engine.
What is DPF regeneration?
Regeneration raises the exhaust temperature so the soot trapped in the filter burns off. It happens on its own while the truck works hard, or it can be started on purpose. Regens that come more and more often mean something needs a look.
What does the SCR catalyst do?
The Selective Catalytic Reduction catalyst is an emission control device that reduces nitrogen oxide (NOx) emissions. DEF is sprayed into the hot exhaust ahead of it, and the catalyst turns the NOx into nitrogen and water.
What happens when the SCR catalyst malfunctions?
A malfunctioning SCR catalyst can lead to increased emissions, poor fuel economy and even engine damage. It usually also sets codes and can put the truck into a derate.
What is DEF?
Diesel exhaust fluid is a mix of urea and water, 32.5 percent urea, sprayed into the exhaust ahead of the SCR catalyst. Bad or contaminated DEF, a clogged doser or a failed DEF pump all show up as SCR problems.
Why is my truck in a derate?
Emissions faults are one of the most common reasons: a clogged DPF, an SCR or DEF problem, or a NOx sensor giving bad readings. The fault gets diagnosed with the codes and the readings before any part is replaced.
Can a bad NOx sensor cause problems?
Yes. The NOx sensors read the exhaust before and after the SCR catalyst. A failed sensor can set codes, affect DEF dosing and cause a derate even when the catalyst itself is fine.
Where can I get truck exhaust repair near Louisville, KY?
Superior Truck & Trailer repairs heavy-duty truck exhaust systems at 3816 Bishop Lane in Louisville, KY, for trucks from Louisville and the surrounding Kentucky and Southern Indiana counties. Call (502) 789-6644 with the truck, the codes and what it is doing.
Leaking, clogged or in a derate?
Get The Exhaust Sorted.
Call Superior Truck & Trailer in Louisville, KY with the truck, any codes and what it is doing. We'll find the leak, the clog or the fault, and fix it.
(502) 789-6644
3816 Bishop Lane #1, Louisville, KY 40218