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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
  • Caterpillar 3406A, 3406B & 3406C Complete Exhaust Manifold - 3 Piece By BESTfit

    Caterpillar 3406A, 3406B & 3406C Complete Exhaust Manifold - 3 Piece By BESTfit

    BESTFIT TRUCK PARTS

    $497.99
    BESTfit Complete Exhaust Manifold Fits CaterpillarThis high quality Complete Caterpillar 3406 Exhaust Manifold is 3 pieces with 3406A, 3406B, and 3406C applications. The exhaust includes only the...
    29-074N754
    SKU:
    29-074N754
    Truck Class:
    Heavy Duty
    Make:
    Freightliner
    Make:
    Volvo
    Make:
    Peterbilt
    Make:
    International
    Make:
    Western Star
    Make:
    Kenworth
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $497.99
    Qty in Cart: 0
    Price:
    $497.99
    Subtotal:
  • FREE SHIPPING
    32 Inch Engine Fan Blade, 11 Blade - Replaces 4735-44003-12

    32 Inch Engine Fan Blade, 11 Blade - Replaces 4735-44003-12

    OPP - ORIGINAL PARTS PROGRAM

    $315.99
    Engine Cooling 32 Inch Fan Blade With 2.56 Inch Pilot HoleThis Engine Fan Blade with 11 blades is a reliable choice for your engine cooling needs and replaces the factory part. It measures 32 inches...
    29-070267
    SKU:
    29-070267
    Truck Class:
    Heavy Duty
    Make:
    Kenworth
    Make:
    Peterbilt
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $315.99
    Qty in Cart: 0
    Price:
    $315.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Scan Gauge Truck Performance Monitor

    Scan Gauge Truck Performance Monitor

    SCAN GAUGE

    $206.99
    ScanGauge D Diagnostic and Performance MonitorThe ScanGaugeD is an incredible tool for monitoring your large diesel-powered vehicle. With 15+ built-in digital gauges, 5 trip computers, and an...
    29-1502135
    SKU:
    29-1502135
    Truck Class:
    Heavy Duty
    Make:
    Kenworth
    Make:
    Freightliner
    Make:
    Peterbilt
    Make:
    Western Star
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $206.99
    Qty in Cart: 0
    Price:
    $206.99
    Subtotal:
  • Kenworth Motor Mount Rear Bushing Kit By BESTfit

    Kenworth Motor Mount Rear Bushing Kit By BESTfit

    BESTFIT TRUCK PARTS

    $235.99
    BESTfit Motor Mount Rear Bushing KitThis motor mount rear bushing kit is designed for Kenworth models with CAT engines. It includes 2 Upper Mounts, 2 Lower Mounts, and hardware for both sides on the...
    02-07045000
    SKU:
    02-07045000
    Truck Class:
    Heavy Duty
    Material Options:
    Plastic/Poly
    Make:
    Kenworth
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $235.99
    Qty in Cart: 0
    Price:
    $235.99
    Subtotal:
  • Steel Oil Pan - Replaces 3680531 & 3687414 By BESTfit For Cummins ISX Engine

    Steel Oil Pan - Replaces 3680531 & 3687414 By BESTfit For Cummins ISX Engine

    BESTFIT TRUCK PARTS

    $379.99
    BESTfit 10-12 Gallon Oil Pan Fits Cummins ISX EnginesThis high quality 10-12 gallon Steel Oil Pan for the Cummins ISX Engine is made of a durable steel construction that ensures a long lasting...
    29-074952540
    SKU:
    29-074952540
    Truck Class:
    Heavy Duty
    Material Options:
    Steel
    Product Type:
    Engine Parts
    Make:
    Freightliner
    Make:
    International
    Make:
    Western Star
    Make:
    Kenworth
    Style Options:
    Cummins
    Ready To Ship:
    Yes
    $379.99
    Qty in Cart: 0
    Price:
    $379.99
    Subtotal:
  • FREE SHIPPING OVER $249
    TPHD 1.875 Inch Oil Filler Cap With Chain For CAT Engine

    TPHD 1.875 Inch Oil Filler Cap With Chain For CAT Engine

    TURNPIKE TRUCK TRIM

    $21.54
    Oil Filler Cap W/ Chain Fits CAT Engine By TPHDKeep your CAT engine properly sealed and protected with the TPHD 1.875 Inch Oil Filler Cap With Chain. Designed for durability and reliable performance,...
    09-072001
    SKU:
    09-072001
    Truck Class:
    Universal
    Material Options:
    Aluminum
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $21.54
    Qty in Cart: 0
    Price:
    $21.54
    Subtotal:
  • FREE SHIPPING OVER $249
    Power Steering Reservoir Kit Replaces 3953866S & Q760236 For Peterbilt, Kenworth, Freightliner

    Power Steering Reservoir Kit Replaces 3953866S & Q760236 For Peterbilt, Kenworth, Freightliner

    AUTOMANN USA

    $52.99
    Power Steering Reservoir Kit - Replaces NMCQ760236, 5839Q761939, Q761939FLG, FGQ761939Keep your steering system performing at its best with this complete Power Steering Reservoir Kit, designed to...
    29-0714001
    SKU:
    29-0714001
    Truck Class:
    Heavy Duty
    Make:
    Kenworth
    Make:
    Peterbilt
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $52.99
    Qty in Cart: 0
    Price:
    $52.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Oil Pan Gasket Replaces 4026684 By BESTfit For Cummins ISX

    Oil Pan Gasket Replaces 4026684 By BESTfit For Cummins ISX

    BESTFIT TRUCK PARTS

    $95.99
    BESTfit Cummins Oil Pan Gasket5. ISX oil pan gasketUpgrade your Cummins Diesel Engine with the ISX Oil Pan Gasket. This quality gasket helps ensures a secure seal for smooth engine performance.* High...
    29-0749525401
    SKU:
    29-0749525401
    Truck Class:
    Heavy Duty
    Make:
    Peterbilt
    Make:
    Kenworth
    Make:
    Freightliner
    Make:
    Western Star
    Make:
    International
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $95.99
    Qty in Cart: 0
    Price:
    $95.99
    Subtotal:
  • BESTfit 100-300 Degrees Fahrenheit Oil Temperature Sensor Replaces 17-04184, 140401, S25202 For Peterbilt 378, 379, 387

    BESTfit 100-300 Degrees Fahrenheit Oil Temperature Sensor Replaces 17-04184, 140401, S25202 For Peterbilt 378, 379, 387

    BESTFIT TRUCK PARTS

    $43.94
    Peterbilt 100-300 Degrees Fahrenheit Oil Temperature SensorMonitor your Peterbilt engine with precision using the 100-300 Degrees Fahrenheit Oil Temperature Sensor Engineered to provide accurate...
    01-07100001
    SKU:
    01-07100001
    Truck Class:
    Heavy Duty
    Make:
    Peterbilt
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $43.94
    Qty in Cart: 0
    Price:
    $43.94
    Subtotal:
  • FREE SHIPPING
    Exhaust Manifold Stud Kit For Caterpillar Engines

    Exhaust Manifold Stud Kit For Caterpillar Engines

    FULL TILT PERFORMANCE

    $349.99
    Caterpillar Exhaust Manifold Stud KitThe Exhaust Manifold Stud Kit for Caterpillar Engines is a must-have for any heavy-duty engine overhaul or maintenance project. This set includes high-quality...
    29-0704095
    SKU:
    29-0704095
    Location:
    Made In USA
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $349.99
    Qty in Cart: 0
    Price:
    $349.99
    Subtotal:
  • FREE SHIPPING OVER $249
    Isspro 2.6 Inch Magnetic Pick Up Sender W/ 3/4 Inch -16 Threading & Wire Leads

    Isspro 2.6 Inch Magnetic Pick Up Sender W/ 3/4 Inch -16 Threading & Wire Leads

    ISSPRO

    $63.99
    Magnetic Pick UpSenderWe offer top of the line aftermarket Isspro magnetic pick up senders for your big rig. This sender is to be used with Isspro speedometers and tachometers. It features wire lead...
    29-071002
    SKU:
    29-071002
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $63.99
    Qty in Cart: 0
    Price:
    $63.99
    Subtotal:
  • FREE SHIPPING
    Air Dog Champ II Air Fuel Separator For CAT Engines 3406E, C13, C15, C16, C18

    Air Dog Champ II Air Fuel Separator For CAT Engines 3406E, C13, C15, C16, C18

    AIRDOG HD

    $508.99
    Air Dog Champ II Air Fuel Separator Fits CAT EnginesGet your AirDog Champ II spin-on high-pressure fuel air separator at 4 State Trucks! It is designed specifically for CAT engines with secondary...
    09-07030120
    SKU:
    09-07030120
    Truck Class:
    Universal
    Location:
    Made In USA
    Material Options:
    Steel
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $508.99
    Qty in Cart: 0
    Price:
    $508.99
    Subtotal:
  • FREE SHIPPING OVER $249
    TPHD 8 Inch Battery Cable Over Molded Harness

    TPHD 8 Inch Battery Cable Over Molded Harness

    TPHD

    $29.68
    3Power your vehicle with confidence using the TPHD 8 Inch Battery Cable Over Molded Harness, a high-quality replacement for OEM cables. Available in both Red and Black 1/0 gauge versions, it fits...
    PPR_204388
    SKU:
    PPR_204388
    Truck Class:
    Universal
    Make:
    Universal Items
    Truck Class:
    Heavy Duty
    Product Type:
    Air, Electrical, & Safety
    Ready To Ship:
    Yes
    $29.68
    Qty in Cart: 0
    Price:
    $29.68
    Subtotal:
  • Front Motor Mount Bushing Kit Replaces K066-385, K066-405 For Kenworth

    Front Motor Mount Bushing Kit Replaces K066-385, K066-405 For Kenworth

    AUTOMANN USA

    $103.99
    Front Motor Mount Bushing Kit Fits Kenworth Replaces K066-385, K066-405The Front Motor Mount Bushing Kit for Kenworth CAT engine models includes rubber mounts and hardware for the front of the engine...
    02-07045001
    SKU:
    02-07045001
    Truck Class:
    Heavy Duty
    Make:
    Kenworth
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $103.99
    Qty in Cart: 0
    Price:
    $103.99
    Subtotal:
  • FREE SHIPPING OVER $249
    2 Quart Power Steering Reservoir Replaces J86-6005 For Peterbilt 300 Series

    2 Quart Power Steering Reservoir Replaces J86-6005 For Peterbilt 300 Series

    AUTOMANN USA

    $214.99
    Power Steering Reservoir Fits Peterbilt 300 Series - Replaces J866005Maintain smooth and reliable steering on your Peterbilt 300 Series with this 2 Quart Power Steering Reservoir, a direct...
    01-0714003
    SKU:
    01-0714003
    Truck Class:
    Heavy Duty
    Make:
    Peterbilt
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $214.99
    Qty in Cart: 0
    Price:
    $214.99
    Subtotal:
  • Isspro Ungrounded Thermocouple W/ 2.25 Inch Probe For Pyrometer Sender

    Isspro Ungrounded Thermocouple W/ 2.25 Inch Probe For Pyrometer Sender

    ISSPRO

    $70.99
    Ungrounded Thermocouple With 2.25 Inch ProbeInstall new gauges in your truck using the ISSPRO Ungrounded Thermocouple. Enthusiasts around the world trust Isspro gauges, sensors, and sending units to...
    29-0710004
    SKU:
    29-0710004
    Truck Class:
    Heavy Duty
    Make:
    GMC
    Make:
    Peterbilt
    Make:
    Freightliner
    Make:
    Mack
    Make:
    International
    Make:
    Volvo
    Make:
    Ford
    Make:
    Kenworth
    Make:
    Western Star
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $70.99
    Qty in Cart: 0
    Price:
    $70.99
    Subtotal:
  • CAT Engines Manifold Spacers Stainless Steel

    CAT Engines Manifold Spacers Stainless Steel

    FULL TILT PERFORMANCE

    $289.99
    Manifold Spacers For CAT Engines Stainless Steel Fits C13, C15, ACERT And 3406 B, C And EThis Bully Dog Stainless Steel Manifold spacer set is a bolt on upgrade that will customize the look and fit...
    29-0704102
    SKU:
    29-0704102
    Location:
    Made In USA
    Truck Class:
    Heavy Duty
    Material Options:
    Stainless Steel
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $289.99
    Qty in Cart: 0
    Price:
    $289.99
    Subtotal:
  • Pittsburgh Power Oil Trap For Cummins NTC And N14 Engine

    Pittsburgh Power Oil Trap For Cummins NTC And N14 Engine

    PITTSBURGH POWER

    $371.99
    Universal Oil Trap For Cummins NTC And N14 Engine, Bolts Directly To Oil PanTired of messy truck undercarriages? The Universal Oil Trap is here to help. Easy to install on Cummins NTC and N14...
    09-071200001
    SKU:
    09-071200001
    Truck Class:
    Universal
    Location:
    Made In USA
    Make:
    Universal Items
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $371.99
    Qty in Cart: 0
    Price:
    $371.99
    Subtotal:
  • Power Steering Reservoir 10.50 Inch - 1002680 For Peterbilt 379

    Power Steering Reservoir 10.50 Inch - 1002680 For Peterbilt 379

    AUTOMANN USA

    $335.99
    Peterbilt 379 Power Steering Reservoir ReplacementReplace a cracked, leaking, or heat-damaged factory tank with this direct-fit Peterbilt power steering reservoir (replaces OEM numbers 10-02680 and...
    01-07120001
    SKU:
    01-07120001
    Truck Class:
    Heavy Duty
    Material Options:
    Steel
    Make:
    Peterbilt
    Product Type:
    Engine Parts
    Height Options:
    10 1/2 Inch
    Ready To Ship:
    Yes
    $335.99
    Qty in Cart: 0
    Price:
    $335.99
    Subtotal:
  • FREE SHIPPING OVER $249
    BESTfit 3 Inch To 2.5 Inch Silicone Coolant Hose Reducer

    BESTfit 3 Inch To 2.5 Inch Silicone Coolant Hose Reducer

    BESTFIT TRUCK PARTS

    $37.44
    BESTfit 3 Inch To 2.5 Inch Silicone Coolant Hose Reducer* High Quality Coolant Hose* 3.00 ID To 2.50 ID* Silicone* 3.00 ID X 2.50 ID X 6 L* Sold Individually* Warranty On Coolant Hose Against Defects...
    09-0702077
    SKU:
    09-0702077
    Truck Class:
    Heavy Duty
    Make:
    Universal Items
    Material Options:
    Silicone
    Product Type:
    Engine Parts
    Ready To Ship:
    Yes
    $37.44
    Qty in Cart: 0
    Price:
    $37.44
    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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