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Engine Parts

Explore a diverse range of new semi-truck engine parts at 4 State Trucks. Discover quality OE and aftermarket replacement filters, belts, sensors, flywheel components, and more online to ensure your engine runs smoothly. Elevate your truck's engine with our quality parts today!
  • Product
  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • BESTfit 12V Electric Heater Valve Replaces MA1685 For Peterbilt, Kenworth

    BESTfit 12V Electric Heater Valve Replaces MA1685 For Peterbilt, Kenworth

    BESTFIT TRUCK PARTS

    $246.99
    BESTfit Electric Operated Heater Valve With 5/8 Inch Outlet Fits PACCAR* High Quality Electric Heater Valve* 12 Volts* 5/8 Inch * New Style Valve Effective 2014* Sold Individually* Warranty On...
    29-070000021
    SKU:
    29-070000021
    Truck Class:
    Heavy Duty
    Make:
    Peterbilt
    Make:
    Kenworth
    Product Type:
    Engine Parts
    $246.99
    Qty in Cart: 0
    Price:
    $246.99
    Subtotal:
  • High Pressure Switch Normally Closed Replaces 404141 By BESTfit

    High Pressure Switch Normally Closed Replaces 404141 By BESTfit

    BESTFIT TRUCK PARTS

    $53.99
    BESTfit NC Type High Pressure Switch With Wire Harness & Female 1/4 Inch Thread* High Quality High Pressure Switch* Application: Multi Fit Applications* Description: High Pressure Switch -Nc* Wire...
    29-070000008
    SKU:
    29-070000008
    Truck Class:
    Heavy Duty
    Product Type:
    Engine Parts
    $53.99
    Qty in Cart: 0
    Price:
    $53.99
    Subtotal:
  • BESTfit 12V Low Pressure Switch With Wire Harness - Replaces RD5-6395-1

    BESTfit 12V Low Pressure Switch With Wire Harness - Replaces RD5-6395-1

    BESTFIT TRUCK PARTS

    $68.99
    BESTfit Low Pressure Switch With 1/4 Inch Female ThreadThis low-pressure switch, replacing OE numbers RD5-6395-1, is a versatile fit for various applications. Running on 12V and equipped with a...
    29-070000007
    SKU:
    29-070000007
    Truck Class:
    Heavy Duty
    Product Type:
    Engine Parts
    $68.99
    Qty in Cart: 0
    Price:
    $68.99
    Subtotal:
  • Power Steering Cooler Replaces 036710 For Western Star 4900

    Power Steering Cooler Replaces 036710 For Western Star 4900

    OPP - ORIGINAL PARTS PROGRAM

    $1,469.99
    Power Steering Cooler Fits Western Star 4900* High Quality Power Steering Cooler* Power Steering Cooler* Fits Western Star 4900* Sold Individually* Warranty On Power Steering Cooler Against Defects...
    29-0509510
    SKU:
    29-0509510
    Truck Class:
    Heavy Duty
    Material Options:
    Aluminum
    Make:
    Western Star
    Product Type:
    Engine Parts
    $1,469.99
    Qty in Cart: 0
    Price:
    $1,469.99
    Subtotal:
  • Blue Oiler Cap Replacement Plug For Dual Dynamics

    Blue Oiler Cap Replacement Plug For Dual Dynamics

    DUAL DYNAMICS

    $6.56
    Replacement Oil Cap Plug For Dual Dynamics - Blue* High Quality Oil Cap Plug* Blue* For 302PC Dual Dynamics* Sold Individually* Warranty On Oil Cap Plug Against Defects In Workmanship & Material From...
    29-050926
    SKU:
    29-050926
    Truck Class:
    Heavy Duty
    Material Options:
    Rubber
    Make:
    Universal Items
    Product Type:
    Frame & Chassis
    $6.56
    Qty in Cart: 0
    Price:
    $6.56
    Subtotal:
  • FREE SHIPPING OVER $249
    Caterpillar 256-8753 Fuel Water Separator

    Caterpillar 256-8753 Fuel Water Separator

    OPP - ORIGINAL PARTS PROGRAM

    $47.63
    Caterpillar 256-8753 Fuel Water Separator* Sold Individually* Warranty On Separator Filter Against Defects In Workmanship & Material From Date Of Purchase*** This Is An OEM Replacement Part/ Not...
    2568753
    SKU:
    2568753
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $47.63
    Qty in Cart: 0
    Price:
    $47.63
    Subtotal:
  • FREE SHIPPING OVER $249
    Caterpillar 1R0749 Secondary Fuel Filter

    Caterpillar 1R0749 Secondary Fuel Filter

    OPP - ORIGINAL PARTS PROGRAM

    $40.57
    Caterpillar Secondary Fuel FilterSecondary Fuel Filters Capture The Smaller Particles That Do The Most Damage To Fuel Injectors And Other Fuel System Components.* High Quality Fuel Filter* Height...
    1R0749
    SKU:
    1R0749
    Truck Class:
    Universal
    Location:
    Made In USA
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $40.57
    Qty in Cart: 0
    Price:
    $40.57
    Subtotal:
  • FREE SHIPPING OVER $249
    Caterpillar 1R0716 Spin-On Oil Filter

    Caterpillar 1R0716 Spin-On Oil Filter

    OPP - ORIGINAL PARTS PROGRAM

    $49.31
    Caterpillar 1R0716 Oil Filter* High Quality Oil Filter* Spin-On Filter* Efficiency Rating: Standard Efficiency* Height 307MM* Installation Type: Spin-On* Diameter / Length: 135.8MM* Media Type:...
    1R0716
    SKU:
    1R0716
    Truck Class:
    Universal
    Location:
    Made In USA
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $49.31
    Qty in Cart: 0
    Price:
    $49.31
    Subtotal:
  • FREE SHIPPING OVER $249
    Exhaust Turbo Pipe Replaces OE WWS 23531-7007 For Western Star 4964

    Exhaust Turbo Pipe Replaces OE WWS 23531-7007 For Western Star 4964

    OPP - ORIGINAL PARTS PROGRAM

    $142.99
    Western Star 4964 Constellation Exhaust Turbo Pipe* High Quality Exhaust Turbo Pipe* Replaces 23531-7007* Sold Individually* Warranty On Exhaust Turbo Pipe Against Defects In Workmanship & Material...
    14-08170070
    SKU:
    14-08170070
    Truck Class:
    Heavy Duty
    Material Options:
    Aluminized Steel
    Make:
    Western Star
    Product Type:
    Exhaust
    $142.99
    Qty in Cart: 0
    Price:
    $142.99
    Subtotal:
  • FREE SHIPPING
    Exhaust Turbo Pipe Replaces OE 04-21317-000 For Western Star 4964

    Exhaust Turbo Pipe Replaces OE 04-21317-000 For Western Star 4964

    OPP - ORIGINAL PARTS PROGRAM

    $370.99
    Western Star 4964 Constellation Exhaust Turbo Pipe* High Quality Exhaust Turbo Pipe* Replaces 04-21317-000* Sold Individually* Warranty On Exhaust Turbo Pipe Against Defects In Workmanship & Material...
    14-08170000
    SKU:
    14-08170000
    Truck Class:
    Heavy Duty
    Material Options:
    Aluminized Steel
    Make:
    Western Star
    Product Type:
    Exhaust
    $370.99
    Qty in Cart: 0
    Price:
    $370.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Exhaust Turbo Pipe Replaces OE A04-22224-000 For Western Star 4964

    Exhaust Turbo Pipe Replaces OE A04-22224-000 For Western Star 4964

    OPP - ORIGINAL PARTS PROGRAM

    $145.99
    Replacement Western Star 4964 Constellation Exhaust Turbo Pipe* High Quality Exhaust Turbo Pipe* Replaces A04-22224-000* Sold Individually* Warranty On Exhaust Turbo Pipe Against Defects In...
    14-08140000
    SKU:
    14-08140000
    Truck Class:
    Heavy Duty
    Material Options:
    Aluminized Steel
    Make:
    Western Star
    Product Type:
    Exhaust
    $145.99
    Qty in Cart: 0
    Price:
    $145.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Schaeffer Diesel Fuel Treatment 2000 Ultra Low Sulfur

    Schaeffer Diesel Fuel Treatment 2000 Ultra Low Sulfur

    AFTERMARKET

    $88.99
    Diesel AdditiveDiesel Treat 2000 Is A Multi-Functional All-Season Diesel Fuel Additive Formulated To Boost Fuel Economy, Improve Cetane Numbers, Reduce Emissions, Fight Fuel Deposits, And Increase...
    137ND
    SKU:
    137ND
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $88.99
    Qty in Cart: 0
    Price:
    $88.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Heavy Duty Speed Sensor With Aluminum Housing With Bullet Terminal For Volvo

    Heavy Duty Speed Sensor With Aluminum Housing With Bullet Terminal For Volvo

    DAYTON / DORMAN

    $67.99
    Heavy Duty Speed Sensor Replaces 8029939Replace your Volvo's aging speed sensor with this Heavy Duty Speed Sensor, engineered for OE 8029939 fitment. Aluminum housing ensures durability, and the...
    13-071002
    SKU:
    13-071002
    Truck Class:
    Heavy Duty
    Make:
    Volvo
    Material Options:
    Aluminum
    Product Type:
    Engine Parts
    $67.99
    Qty in Cart: 0
    Price:
    $67.99
    Subtotal:
  • Accelerator Pedal Sensor Replaces 3917928 For Volvo

    Accelerator Pedal Sensor Replaces 3917928 For Volvo

    DAYTON / DORMAN

    $431.99
    Accelerator Pedal Sensor Fits VolvoEnsure precise acceleration response with this Volvo Accelerator Pedal Sensor, engineered for reliability and exact fit. The angled 1.181-inch sensor body is...
    13-071001
    SKU:
    13-071001
    Truck Class:
    Heavy Duty
    Make:
    Volvo
    Product Type:
    Engine Parts
    $431.99
    Qty in Cart: 0
    Price:
    $431.99
    Subtotal:
  • On Sale
    Limited Quantity Available
    TPHD 9.25 X 12.25 X 2.56 Inch AC Evaporator For Volvo VNL

    TPHD 9.25 X 12.25 X 2.56 Inch AC Evaporator For Volvo VNL

    TPHD

    Now: $23.48
    Was: $123.99
    AC Evaporator Fits Volvo VNL Gen I & Gen II By TPHDKeep your Volvo VNL air conditioning system operating at peak efficiency with the TPHD 9.25 x 12.25 x 2.56 Inch AC Evaporator, a high-quality...
    13-070004
    SKU:
    13-070004
    Truck Class:
    Heavy Duty
    Material Options:
    Aluminum
    Make:
    Volvo
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    Now: $23.48
    Was: $123.99
    Qty in Cart: 0
    Price:
    Now: $23.48
    Was: $123.99
    Subtotal:
  • BESTfit Expansion Block Replaces 85120289 For Volvo VHD, VN

    BESTfit Expansion Block Replaces 85120289 For Volvo VHD, VN

    BESTFIT TRUCK PARTS

    $74.99
    BESTfit Flange-Mount Expansion Block Fits Volvo VHD & VNL Gen IIKeep your Volvo VHD or VN air conditioning operating smoothly with the BESTfit Expansion Block, a reliable OE 85120289 replacement...
    13-070000003
    SKU:
    13-070000003
    Truck Class:
    Heavy Duty
    Make:
    Volvo
    Product Type:
    Engine Parts
    $74.99
    Qty in Cart: 0
    Price:
    $74.99
    Subtotal:
  • Aluminum AC Evaporator Replaces 2734038 For Volvo VHD, VNL Gen I

    Aluminum AC Evaporator Replaces 2734038 For Volvo VHD, VNL Gen I

    AUTOMANN USA

    $217.99
    AC Evaporator Fits Volvo VHD, VNL Gen I 1995-2003Bring dependable cab cooling back to your Volvo with this Aluminum AC Evaporator. Built from high-quality aluminum, it offers excellent heat transfer...
    13-070000001
    SKU:
    13-070000001
    Truck Class:
    Heavy Duty
    Make:
    Volvo
    Product Type:
    Engine Parts
    $217.99
    Qty in Cart: 0
    Price:
    $217.99
    Subtotal:
  • Transfer Case Shift Motor Replaces 19125578, 19125856, 88962312 For GMC, Chevrolet

    Transfer Case Shift Motor Replaces 19125578, 19125856, 88962312 For GMC, Chevrolet

    DAYTON / DORMAN

    $329.99
    Transfer Case Shift Motor Fits GMC & Chevrolet Pickups/SUVs* High Quality Transfer Case Shift Motor* Housing Material: Metal* Terminal Type: 5 Pin* Wiring Harness Included: Yes* Sold Individually*...
    12-07120011
    SKU:
    12-07120011
    Truck Class:
    Heavy Duty
    Make:
    Mack
    Product Type:
    Engine Parts
    $329.99
    Qty in Cart: 0
    Price:
    $329.99
    Subtotal:
  • Valve Cover Replaces 12642655, 8-12642-655-0 For GMC, Isuzu, Saab Driver Side

    Valve Cover Replaces 12642655, 8-12642-655-0 For GMC, Isuzu, Saab Driver Side

    DAYTON / DORMAN

    $113.99
    Driver Side Valve Cover Fits GMC, Isuzu, Saab* High Quality Engine Valve Cover* Made Of Aluminum* Dimensions - 19.52 Inch Length - 4.52 Inch Width - 2.25 Inch Height* Oil Filler Cap NOT Included*...
    12-07120008
    SKU:
    12-07120008
    Truck Class:
    Heavy Duty
    Make:
    Mack
    Make:
    Isuzu
    Product Type:
    Engine Parts
    $113.99
    Qty in Cart: 0
    Price:
    $113.99
    Subtotal:
  • Power Steering Cooler Replaces 15295843, 25895896 For GMC, Chevrolet, Cadillac

    Power Steering Cooler Replaces 15295843, 25895896 For GMC, Chevrolet, Cadillac

    DAYTON / DORMAN

    $137.99
    Power Steering Cooler Fits GMC, Chevrolet & Cadillac* High Quality Power Steering Cooler* Made Of Steel* Color: Black* Fitting Type: Barb* Height: 2.007 In* Inlet Inside Diameter: 0.275 In* Inlet...
    12-07120005
    SKU:
    12-07120005
    Truck Class:
    Heavy Duty
    Make:
    Mack
    Product Type:
    Engine Parts
    $137.99
    Qty in Cart: 0
    Price:
    $137.99
    Subtotal:
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Adding your products to cart

Shop Semi Truck Engine Parts

Your truck’s engine is the heart of your business. When it’s running right, you’re making money. When it’s not, you’re losing time and profits. That’s why 4 State Trucks offers the semi truck engine parts you need to keep your rig on the road and working hard. We stock the critical components that solve real problems for real drivers. Whether you’re fighting diesel fuel system issues, truck engine cooling problems, or just normal wear and tear, the right replacement parts can mean the difference between staying ahead—or getting left behind.
- Boost performance and efficiency: Upgrading worn components helps your engine breathe better, burn cleaner, and run stronger.
- Protect your investment: Durable parts cut down on wear, extend engine life, and help you avoid expensive breakdowns.
- Save time and money: Easy-to-install designs mean faster repairs and less time off the road.
- Stay ready for every mile: Quality parts give you the confidence to tackle tough loads, long hauls, and everything in between. It’s not just about replacement—it’s about protecting your truck, your schedule, and your bottom line.

Best Features of Our Heavy Duty Truck Engine Parts


- Built tough for heavy-duty commercial use.
- Fits a wide range of semi truck makes and models.
- Helps cut downtime and avoid major repairs.
- Fast shipping and expert support when you need it.

Shop Diesel Engine Truck Parts at 4 State Trucks

Stay ahead of engine problems before they cost you. Shop at 4 State Trucks today and keep your semi-truck’s engine, fuel, and even exhaust system running at prime capacity.

Frequently Asked Questions About Semi-Truck Engine Parts

What engine parts are compatible with my specific truck model and year?

Engine part compatibility varies significantly between truck manufacturers, models, and production years. For accurate fitment, you'll need your engine serial number and model information (found on the engine data plate), along with your truck's OEM. Common engine models include Caterpillar C15/C13, Cummins ISX/N14, Detroit DD15/Series 60, and Paccar MX-13. Always cross-reference part numbers with your engine's service manual or contact our technical support team with your specific engine details to ensure proper fitment.

How difficult is it to install engine components like water pumps, turbochargers, or EGR valves?

Installation difficulty varies by component and your mechanical experience. Basic items like air filters, belts, and thermostats typically require standard tools and 30-60 minutes. Complex components like turbochargers, EGR valves, or fuel injectors often require specialized tools, diagnostic equipment, and 2-8 hours of labor. Many drivers handle oil coolers, water pumps, and sensors themselves with proper service manuals. For critical components affecting emissions or requiring ECM programming, professional installation is recommended to maintain warranties and ensure proper operation.

What's the difference between OEM and aftermarket engine parts in terms of quality and longevity?

OEM parts are manufactured to original equipment specifications and typically offer the longest service life and exact fit. Quality aftermarket parts from reputable manufacturers like Dorman, PAI, or Interstate-McBee often match OEM performance at 20-40% lower cost. Premium aftermarket parts usually carry 1-2 year warranties compared to OEM's 2-3 years. Budget aftermarket options may save 50-70% but often have shorter lifespans and limited warranties. For critical components like injectors or turbochargers, OEM or premium aftermarket is recommended. For maintenance items like filters, gaskets, and hoses, quality aftermarket parts provide excellent value.

Which engine parts should I keep as spares to avoid roadside breakdowns?

Essential spare parts include serpentine belts, coolant hoses (especially the lower radiator hose), thermostats, fuel filters, and a complete set of sensors (coolant temp, oil pressure, boost pressure). Many drivers also carry a spare water pump, alternator, and starter due to their failure frequency. For emissions-equipped trucks (2007+), there may be a spare EGR valve gasket and DPF pressure sensors can prevent costly downtime. Keep manufacturer-specific items like turbo boost hoses and intercooler boots that aren't readily available at general parts stores. Total investment for a basic spare parts kit typically runs $500-1500.

How can I tell if an engine part is failing before it causes major damage?

Early warning signs vary by component. Water pumps show coolant leaks, wobbling pulleys, or grinding noises. Turbochargers exhibit excessive smoke, oil consumption, or whistling sounds. Injectors cause rough idle, white/black smoke, or poor fuel economy. EGR valves trigger check engine lights, rough running, or excessive soot buildup. Oil coolers show oil in coolant or dropping oil pressure. Regular oil analysis (every 15,000 miles) can detect bearing wear, coolant intrusion, or fuel dilution before catastrophic failure. Installing aftermarket gauges for boost pressure, EGT, and oil temperature provides real-time monitoring of engine health.


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