2017-2019 Chevy Duramax L5P Parts & Upgrades

The L5P in the 2017-2019 Silverado 2500HD and 3500HD

GM dropped the LML after 2016 and put the all-new L5P into the same 2015-2019 K2XX HD body, which is why our catalog splits 2017-2019 from the 2020-and-up trucks. The L5P brought a cast-iron block with induction-hardened bores and five cross-bolted main caps, a bigger forged crank, stronger rods, pistons with reinforced crowns fed by cooling jets that flow about 50% more oil than the LML's, and an oil cooler roughly 50% larger. Fuel starts at a factory electric lift pump, the first one fitted to a Duramax, runs through a frame-rail cartridge filter (ACDelco TP1015) to the Denso HP4 pump, then to Denso GS4 solenoid injectors at up to 29,000 psi and as many as seven injection events per cycle. Air is pushed by a BorgWarner variable-geometry turbo with an electric vane actuator, and that same turbo provides the exhaust brake. Every 2017-2019 truck makes 445 hp at 2,800 rpm and 910 lb-ft at 1,600 rpm behind an Allison 1000 six-speed automatic (RPO MW7).

What fails and why

The iron holds up; the connectors and the plastic do not. The injector electrical connector at cylinder 4 is the signature complaint: terminals degrade, contact goes intermittent, and the truck sets P0204, P020D and P0300-family codes, shakes at idle and drops into limp mode while the injector itself is usually fine. There is no consistent mileage pattern, and it shows up most on 2017-2019 trucks. Glow plugs and the glow plug control module are the cold-start problem (codes P0671-P0678, long cranking, white smoke at startup), reported from about 50,000 miles up. The intake MAP sensor fouls with EGR soot and oil vapor, commonly from 30,000-50,000 miles and again after that, and a fouled sensor feeds the ECM false boost data: sluggish acceleration, lazy spool, rough idle, misfire codes. Water pumps get called out at 60,000-80,000 miles by some shops and in the 150,000-250,000-mile wear range by others, usually starting as a slow weep and a rising temperature gauge. The plastic upper radiator hose fittings and the edges of the coolant reservoir develop hairline cracks after years of heat, which you find as orange DEX-COOL residue and low-coolant warnings. Factory plastic charge pipes and boots crack or blow off under heavy-tow boost, which is an instant P0299 and limp mode. Further up the odometer, the VGT vane actuator fails, often quoted around 100,000-130,000 miles, with P0046 or P0299 and a weak or inconsistent exhaust brake; carbon on the vanes does the same thing more slowly. On the transmission side, a thermal bypass valve stuck closed keeps fluid out of the cooler and the Allison runs hot. Downstream, NOx sensors are the most frequent aftertreatment failure, and short-trip, idle-heavy trucks load the DPF and fail regens.

Stock replacement vs. upgrade

A lot of this is a service part, not a project. When the misfire is electrical, replace the injector connectors instead of the injectors. Use OEM ACDelco NOx sensors, because aftermarket sensors have a poor track record on this platform. Stay on ACDelco TP1015 elements; the published schedule allows 22,500 miles and plenty of shops run them at 10,000, and fuel contamination, water, or air drawn past a mis-seated filter O-ring is the leading cause of HP4 and injector trouble. On a truck that tows, replacing the water pump preventively at the 60,000-80,000-mile mark is cheap, and a billet transmission fluid thermal bypass valve (PPE 125065020) flows more than the factory valve even when the factory valve is working. Cracked plastic coolant fittings are worth replacing with aluminum fittings and reinforced hose rather than more plastic. For upgrades, start with the restriction: Banks' 3.5-inch Boost Tubes (25999, CARB EO D-161-155) replace the plastic charge pipes, and the Monster-Ram turbo inlet elbow (42792, CARB EO D-161-158) opens the pinched factory inlet. Added power goes one of two ways. An inline module keeps the ECM untouched, as with the Banks Derringer 66652 (CARB EO D-161-149, up to 61 hp and 112 lb-ft). Flash tuning needs the factory-locked ECM and TCM opened, which is what the Edge CTS3 and Locksmith package does for up to 150 hp and 350 lb-ft, with every piece of factory emissions equipment required to be present and working; that kit cannot ship to California. Know the ceilings first: the stock turbo is good for roughly 550-570 rwhp, the Allison 1000 starts slipping its clutches near 500 rwhp and answers with P0700 and third-gear limp, so a converter, frictions and TCM line pressure come before more fuel.

What we carry

Everything in this collection is listed for a 2017-2019 L5P Silverado. PPE brings forged steering assemblies and XR tie rod kits, thermal bypass valves, oil filters, differential covers and up-pipe gaskets. Wehrli Custom Fabrication covers the cooling and charge-air side with thermostat housings, upper coolant pipes, OEM-placement coolant tank kits, intercooler pipe kits, up-pipe bolt and turbo gasket kits, billet exhaust manifold and up-pipe kits, and a Stage 2 high-flow intake bundle. Merchant Automotive and Alliant Power handle Allison and fuel-system service parts, including HP4 pump installation gasket kits and transmission reseal kits. MBRP covers exhaust, Mishimoto and BD Diesel cooling and drivetrain hardware, S&B and Banks Power intake and airflow parts, FASS water separation and filtration, Edge Products monitors, EGT and pressure sensor kits and tuning hardware, B&W Trailer Hitches and Air Lift the towing end, BDS Suspension lift kits and heavy-duty tie rods, and ACDelco glow plugs and filters. XDP and Fleece Performance add hardware and service kits, Hot Shot's Secret and Lucas Oil cover engine oil and fuel additives, and there are platform tools in here too. It all sits under the Duramax hub.

Fitment notes

The 2020 redesign moved these trucks to the T1XX body, so a lot of parts stop at 2019. The oil filter is PF2232 on 2017-2019 and PF26 on 2020-up; the air filter is A3231C here and A3248C later, and the two are different shapes. Intake kits and airboxes are 2017-2019-specific because the hood, scoop and airbox all changed. Transmission parts are Allison 1000 six-speed items, and nothing from the 2020+ ten-speed crosses either direction. Suspension and steering linkage are cataloged as one 2011-2019 HD range, but 2WD and 4WD kits differ, front differential parts apply to 4x4 trucks only, and the rear axle is the AAM 11.5 even though some catalogs print 11.8. MAP relocation spacers are year-split: 2017-2019 trucks have the single upper sensor, so the upper kit (Banks 64410) is the one that applies. For towing, read the trailering label on the door jamb instead of a headline number, because ratings move with cab, drive, single or dual rear wheel, and axle ratio. Two paperwork checks: make sure the block heater cord recalls (19V-328 and 21V-496) were performed on a heater-equipped truck, and check dual-tank trucks against the fuel tank recalls. If a listing's year range is close but not clear, verify by VIN.

Frequently asked questions

Does my 2017-2019 Silverado have the Bosch CP4 pump?

No. The Bosch CP4.2 was used on the 2011-2016 LML. The L5P uses a Denso HP4 with a solid-lifter design that is far more tolerant of poor fuel. Failures are uncommon, but when a high-pressure pump does come apart it sends debris through the rails, lines and injectors, so the accepted repair is the whole high-pressure side rather than a pump alone.

Why does my truck throw a cylinder 4 misfire and go into limp mode?

That is the known injector connector issue. The connector terminals degrade and make intermittent contact, which sets P0204, P020D and P0300-family codes, gives you a rough shaking idle and trips limp mode. The injector itself is usually fine. Have the connector inspected, and replaced with a better connector if needed, before anyone quotes you a set of eight injectors.

How often should I change the fuel filter?

The published schedule allows 22,500 miles or two years on the TP1015 cartridge, and many shops cut that to about 10,000 miles. Contaminated fuel, water, and air pulled in past a mis-seated filter O-ring are the leading causes of injector and pump trouble on the L5P, so the shorter interval is the cheaper one. Use the ACDelco element and seat the O-ring carefully.

Can I add power to a 2017-2019 L5P?

Yes, in two compliant ways. An inline module such as the Banks Derringer 66652 carries CARB EO D-161-149, adds up to 61 hp and 112 lb-ft, and never reflashes the ECM. Flash tuning requires unlocking the factory-locked ECM and TCM with Edge's Locksmith and a CTS3; that unlock is permanent and tied to one VIN, all factory emissions equipment must be present and working, and the kit cannot ship to California.

Will parts from a 2020 Silverado HD fit my 2019?

Often not. The 2020 trucks are a new body on a new frame with new axles and a ten-speed in place of the Allison 1000, and even service items like the oil and air filters changed. Some engine, turbo and fuel parts are listed across 2017-2023, but chassis, cab, intake and transmission parts generally are not. Check the year range printed on the listing, or send us the VIN.

Not sure what fits? Call the shop at the number in the header, or use the fitment checker on any product page. We install everything we sell.