How Much Does Diesel Injector Replacement Cost?
Fuel system · Class 8 tractor · Class 6–7 medium duty · Class 3–5 · Diesel pickup
Short answer
$550–$10,360
TODO(verify): A full set of six injectors on a Class 8 engine commonly runs $2,500 to $7,000 installed — $1,800 to $5,400 in parts plus four to twelve hours depending on whether the engine has overhead access or requires deeper disassembly.
Single injector replacement, Class 8 engine with overhead access
- Parts
- $300–$900
- Labor
- 2–5 hr × $125–$210/hr = $250–$1,050
Provisional figures — pending verification against our receipt dataset.
Labor rate: provisional national placeholder — TODO(verify), not yet from our collected dataset. How we build these ranges.
TODO(verify): single injector parts and labor. Includes valve lash and injector height reset where applicable.
What you are actually paying for
Injectors are the repair where the single-injector-versus-full-set question decides the invoice. One failed injector on an engine with 600,000 miles usually means the others are close behind, and the labor to go back in is identical. The other thing worth knowing before the quote: fuel contamination kills injectors in sets, and if that is what happened, the filters, lines, and sometimes the pump are part of the job whether or not they are on the first estimate.
What it costs in each situation
Priced at provisional national placeholder — TODO(verify), not yet from our collected dataset. Parts and hours are the figures worth arguing about; the rate is usually not negotiable.
| Scenario | Class | Parts | Hours | Total |
|---|---|---|---|---|
| Single injector replacement, Class 8 engine with overhead accessTODO(verify): single injector parts and labor. Includes valve lash and injector height reset where applicable. | Class 8 tractor | $300–$900 | 2–5 | $550–$1,950provisional |
| Full set of six injectors, Class 8 engineTODO(verify): full-set pricing and standard repair time by engine family. | Class 8 tractor | $1,800–$5,400 | 4–12 | $2,300–$7,920provisional |
| Injector set plus fuel system cleaning after contaminationTODO(verify): contamination cleanup scope and pricing. May include tank, lines, filters, and high-pressure pump. | Class 8 tractor | $2,400–$7,000 | 6–16 | $3,150–$10,360provisional |
| Medium-duty injector setTODO(verify): medium-duty parts and labor. | Class 6–7 medium duty | $1,100–$3,200 | 3.5–9 | $1,538–$5,090provisional |
| Diesel pickup injector set, eight injectorsTODO(verify): pickup injector pricing and labor. Access differs sharply between the 6.7 Power Stroke, L5P, and 6.7 Cummins. | Diesel pickup | $1,500–$4,500 | 5–14 | $2,125–$7,440provisional |
What moves the price
- One injector or the whole set
- The labor is nearly the same either way on most engines. On a high-mileage engine, replacing one and going back in six months for another is the expensive path.
- Injector type
- Common rail, EUI, and HEUI injectors price and install differently. Confirm which the engine uses and which is quoted.
- New, reman, or rebuilt
- The spread is wide. A properly remanufactured injector with a flow test certificate is a legitimate choice; an unbranded rebuild is a gamble on a part that sits inside your engine.
- Whether the failure was contamination
- Water or debris in the fuel takes out injectors in groups and usually the high-pressure pump with them. Installing new injectors into a contaminated system destroys them.
- Calibration and trim codes
- Most modern injectors carry a trim or calibration code that must be programmed to the ECM. Skipping it produces rough running and poor economy on brand-new parts.
- Cup and seal service
- On engines with injector cups, a leaking cup means coolant or fuel where it should not be. Cup replacement is separate labor and sometimes needs a specialty tool.
Symptoms that lead here
- Rough idle, misfire, or a distinct knock from one cylinder
- Hard starting, especially cold
- White or black smoke
- Fuel in the oil, or rising oil level
- Excessive fuel return flow on a return-line test
- Cylinder cutout test showing one cylinder contributing nothing
- Fuel economy dropping with no route or load change
How to pay less without buying trouble
- 1
Ask for a cylinder cutout test and a return flow test before authorising anything. Those two tests identify which injectors are actually bad.
- 2
On a high-mileage engine, price the full set against a single. The labor overlap usually makes the set the cheaper long-run choice.
- 3
Insist injector trim codes are programmed. Ask the shop to confirm it in writing.
- 4
Change fuel filters on schedule and drain the water separator. Injector failure from contamination is preventable and expensive.
- 5
If contamination is suspected, have the fuel sampled before new parts go in. Putting injectors into dirty fuel is throwing them away.
- 6
Ask whether the quote includes valve lash adjustment where the engine requires it after injector service.
Questions people ask before they book this
Should I replace all the injectors at once?
On a high-mileage engine, usually yes — the labor is shared and the remaining injectors have the same hours. On a low-mileage engine with a single clear failure, replacing one is reasonable.
How long do diesel injectors last?
Highly variable, and driven mostly by fuel cleanliness and filter discipline rather than mileage alone. TODO(verify): mileage distribution from submitted receipts once we have data.
Are remanufactured injectors safe to use?
From a reputable remanufacturer with a flow test certificate, yes — many fleets run them. What to avoid is an unbranded rebuild with no test data and no warranty.
Why does the shop need to program the new injectors?
Each injector is manufactured with slight flow variation, and its calibration code tells the ECM how to compensate. Without it the engine runs unevenly on brand-new parts.
Shops that quote this job
We call every shop before it appears here, and publish the date.
Sample records only — seeded to demonstrate the directory. None of these numbers has been called.
Memphis, TN · 24/7 · mobile service
Indianapolis, IN · Mon-Fri 6am-6pm · mobile service
Laredo, TX · Mon-Sat 6am-9pm · mobile service
Phoenix, AZ · 24/7 · mobile service
Fault codes that lead to this repair
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