2003 Hummer H1 Engine Parts

This table covers the Camshaft bearings. Typical signs include a growl that rises with speed, or play in the shaft or hub. Set preload the way the notes specify. A dry or crushed bearing fails quickly. Read more

One part is listed for the 2003 Hummer H1 — ENGINETECH CC420.

This table covers the connecting rods between each piston and the crankshaft. Read more

One part is listed for the 2003 Hummer H1 — ENGINETECH ECR307.

This table covers the bearings in the connecting-rod big ends. Typical signs include a growl that rises with speed, or play in the shaft or hub. Set preload the way the notes specify. A dry or crushed bearing fails quickly. Read more

2 Connecting Rod Bearing parts are listed for the 2003 Hummer H1, from ENGINETECH and KING ENGINE BEARINGS.

This group includes ENGINETECH BB100J and KING ENGINE BEARINGS CR873CP.

This table covers lower / conversion gasket sets for oil-pan and related joints. Typical signs include the leaks that sent the engine or gearbox to the bench. Use every gasket the set is meant for that opening — leftover unused pieces usually belong to another configuration. Read more

5 Conversion / Lower Gasket Set parts are listed for the 2003 Hummer H1, from APEX, ENGINETECH, FEL-PRO and 2 other brands. APEX ACS3091 carries the "Popular" badge.

Listed part numbers: APEX ACS3091, ENGINETECH GM65CS and FEL-PRO CS87262, plus the other parts above.

This table covers the main bearings that support the crankshaft in the block. Typical signs include a growl that rises with speed, or play in the shaft or hub. Set preload the way the notes specify. A dry or crushed bearing fails quickly. Read more

3 Crankshaft Main Bearing parts for the 2003 Hummer H1 come from 2 brands — KING ENGINE BEARINGS and ENGINETECH.

This group includes ENGINETECH BC102J, KING ENGINE BEARINGS MB5257SI and KING ENGINE BEARINGS MB5257SIX.

This table covers the sleeves used to restore a grooved crankshaft seal surface. Read more

7 Crankshaft Repair Sleeve parts for the 2003 Hummer H1 come from 4 brands — TIMKEN, WJB / INMOTION PARTS, BCA and 1 other brand. The "Popular" part is TIMKEN KWK99233.

Part numbers include TIMKEN KWK99233, WJB / INMOTION PARTS WS99452 and BCA NS99233, among others listed above.

This table covers the front and rear seals that keep oil in at the crankshaft. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again. Read more

11 Crankshaft Seal parts for the 2003 Hummer H1 come from 7 brands — NATIONAL, TIMKEN, BCA and 4 other brands. The "Popular" part is FEL-PRO BS40604.

This table covers the cylinder heads that close the top of the block. Read more

2 Cylinder Head parts for the 2003 Hummer H1 come from ENGINETECH.

Part numbers include ENGINETECH EHC3951 and ENGINETECH EHC395.

This table covers the bolts that clamp the cylinder head to the block. Read more

6 Cylinder Head Bolt parts are listed for the 2003 Hummer H1, from ENGINETECH, FEL-PRO, APEX and 3 other brands. ENGINETECH HB116 carries the "Popular" badge.

This group includes ENGINETECH HB116, FEL-PRO ES72724 and APEX AHB391 and the remaining parts above.

This table covers the head gaskets that seal the block to the cylinder head. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

8 Cylinder Head Gasket parts are listed for the 2003 Hummer H1, from FEL-PRO, APEX, MAHLE / CLEVITE and 1 other brand. FEL-PRO 9701PT carries the "Popular" badge.

This group includes FEL-PRO 9701PT, FEL-PRO 9521PT and APEX AHG391 and the remaining parts above.

This table covers multi-piece gasket sets for a cylinder-head job. Typical signs include the leaks that sent the engine or gearbox to the bench. Use every gasket the set is meant for that opening — leftover unused pieces usually belong to another configuration. Read more

6 Cylinder Head Gasket Set parts are listed for the 2003 Hummer H1, from ENGINETECH, APEX, FEL-PRO and 2 other brands. APEX AHS3091 carries the "Popular" badge.

This group includes APEX AHS3091, FEL-PRO HSU8726 and ENGINETECH GM65HSA and the remaining parts above.

This table covers the Cylinder Head Spacer shims. Read more

One part is listed for the 2003 Hummer H1 — SBI 2302104.

This table covers full gasket kits covering the joints opened in an engine rebuild. Typical signs include the leaks that sent the engine or gearbox to the bench. Use every gasket the set is meant for that opening — leftover unused pieces usually belong to another configuration. Read more

4 Engine Kit Gasket Set parts are listed for the 2003 Hummer H1, from FEL-PRO, APEX and ENGINETECH.

Listed part numbers: APEX AFS3091, ENGINETECH GM65K1 and FEL-PRO 2601772, plus the other parts above.

This table covers the exhaust valves that let combustion gas out of the cylinder. Typical signs include a circuit that will not hold, a whistle, or a code for this valve. A stuck valve is often debris. Clean the ports before installing the new one. Read more

3 Exhaust Valve parts for the 2003 Hummer H1 come from 3 brands — ENGINETECH, QUALCAST and SBI.

Listed part numbers: ENGINETECH V2679S, QUALCAST 101780S and SBI 01780S.

This table covers the Expansion plugs. Typical signs include a leak at the drain or glow-plug hole, or a plug that has rounded off. Replace the crush washer and torque to the spec in the notes. Read more

3 Expansion Plug parts are listed for the 2003 Hummer H1, from ENGINETECH and QUALCAST.

Listed part numbers: ENGINETECH PK59, ENGINETECH PK59B and QUALCAST 9798B.

This table covers the gaskets between the intake manifold and the cylinder head. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

5 Intake Manifold Gasket parts are listed for the 2003 Hummer H1, from FEL-PRO, APEX, MAHLE / CLEVITE and 2 other brands. FEL-PRO MS91585 carries the "Popular" badge.

Listed part numbers: FEL-PRO MS91585, APEX AMS3910 and MAHLE / CLEVITE MS15306, plus the other parts above.

This table covers the gaskets that seal the Intake Plenum. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

5 Intake Plenum Gasket parts for the 2003 Hummer H1 come from 5 brands — FEL-PRO, APEX, MAHLE / CLEVITE and 2 other brands. The "Popular" part is FEL-PRO MS901761.

Part numbers include FEL-PRO MS901761, APEX AMS3912 and MAHLE / CLEVITE MS16316, among others listed above.

This table covers the intake valves that let air (and fuel, on port-injected engines) into the cylinder. Typical signs include a circuit that will not hold, a whistle, or a code for this valve. A stuck valve is often debris. Clean the ports before installing the new one. Read more

3 Intake Valve parts for the 2003 Hummer H1 come from 3 brands — ENGINETECH, QUALCAST and SBI.

Part numbers include ENGINETECH V2006, QUALCAST 101484 and SBI 01484.

This table covers the mounts that hold the engine to the chassis. Typical signs include a clunk on takeoff, a vibration at idle, or a separated rubber insert. Support the powertrain before unbolting a mount, and torque the fasteners in the notes. Read more

2 Motor Mount parts for the 2003 Hummer H1 come from 2 brands — DEA / MARMON RIDE CONTROL and WESTAR.

Part numbers include DEA / MARMON RIDE CONTROL A5447 and WESTAR EM4001.

This table covers the engine oils listed by grade and specification for this engine. Typical signs include a low-oil lamp, knocking after a long interval, or oil that has gone thin and black well before the next service. Match the viscosity and spec in the notes (and on the filler cap). The tables group grades — they are not interchangeable. Read more

9 Oil parts for the 2003 Hummer H1 come from 4 brands — VALVOLINE, LIQUI MOLY, LUCAS OIL and 1 other brand. The "Popular" part is VALVOLINE 773780.

The Conventional section lists 3 options from LIQUI MOLY and VALVOLINE — grouped under the catalog's "Conventional" designation — the notes column spells out what sets them apart. VALVOLINE 773780 is listed in this group.

The Heavy Duty / Diesel section lists 2 options from LIQUI MOLY and LUCAS OIL — grouped under the catalog's "Heavy Duty / Diesel" designation — the notes column spells out what sets them apart. LIQUI MOLY 2044 is listed in this group.

The Racing section lists 1 option from IDEMITSU — grouped under the catalog's "Racing" designation — the notes column spells out what sets them apart. IDEMITSU 30018100750 is listed in this group.

The Synthetic Blend section lists 3 options from VALVOLINE — synthetic-blend oils. VALVOLINE 818289 is listed in this group.

This group includes VALVOLINE 773780, LIQUI MOLY 22038 and LIQUI MOLY 20383 and the remaining parts above.

This table covers the crush washers and gaskets under the oil drain plug. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

4 Oil Drain Plug Gasket parts are listed for the 2003 Hummer H1, from APEX, FEL-PRO, MAHLE / CLEVITE and 1 other brand.

This group includes APEX ADP1902, FEL-PRO 70822 and MAHLE / CLEVITE 2051 and the remaining parts above.

This table covers the caps on the oil filler neck. Read more

3 Oil Filler Cap parts for the 2003 Hummer H1 come from 3 brands — GATES, MOTORAD and SKP.

This group includes GATES 31103, MOTORAD MO99 and SKP SKMO99.

This table covers the oil filters that screw onto this engine's filter mount. Typical signs include low oil pressure after a service, or a filter that will not spin off because the old gasket stayed on the block. Lube the new gasket and tighten to the spec on the box; a double-gasket install dumps the sump on the first drive. Read more

19 Oil Filter parts for the 2003 Hummer H1 come from 14 brands — BOSCH, PUROLATOR, WIX and 11 other brands. The "Popular" part is WIX 51060XP.

The Economy section lists 8 options from PUROLATOR, BOSCH, CHAMP / LUBER-FINER and 4 other brands — the catalog's value-priced group. BOSCH 72235WS is listed in this group.

The High Performance / Heavy Duty section lists 4 options from WIX, BOSCH, FRAM and 1 other brand — grouped under the catalog's "High Performance / Heavy Duty" designation — the notes column spells out what sets them apart. WIX 51060XP is listed in this group.

In the Standard Replacement grade, ACDELCO, FRAM, WIX and 4 other brands supply 7 parts: built to original-equipment specification. A representative part number is ACDELCO PF1218.

This table covers the Oil Filter Adapter Gasket O-rings. Typical signs include a seep at a fitting or a housing that weeps after a service. Lube the new O-ring with the fluid it will see, and do not roll it into the groove. Read more

One part is listed for the 2003 Hummer H1 — FEL-PRO ES73229.

This table covers the Oil Level sensors. Typical signs include a warning lamp, a stored code, or a reading that drops out when the harness is wiggled. Inspect the connector and ground before replacing the sensor — wiring faults are often condemned as bad sensors. Read more

This group shows a single part: ACDELCO D8055.

This table covers the oil pans that hold the engine's oil sump. Read more

3 Oil Pan parts are listed for the 2003 Hummer H1, from DORMAN, SKP and ULTRA-POWER.

Listed part numbers: DORMAN 264163 and SKP SK264163, plus the other parts above.

This table covers the gaskets between the oil pan and the block. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

5 Oil Pan Gasket parts for the 2003 Hummer H1 come from 4 brands — VICTOR REINZ, APEX, FEL-PRO and 1 other brand. The "Popular" part is VICTOR REINZ 703141410.

This group includes VICTOR REINZ 703141410, APEX AOP391 and FEL-PRO OS34406 and the remaining parts above.

This table covers the Oil pumps. Typical signs include noise from the pump, no pressure, or fluid that never arrives at the outlet. Prime or fill the pump as the notes require. A dry start is a common way to kill a new unit. Read more

3 Oil Pump parts for the 2003 Hummer H1 come from 2 brands — MELLING and SEALED POWER.

The High Volume / Pressure section lists 1 option from MELLING — grouped under the catalog's "High Volume / Pressure" designation — the notes column spells out what sets them apart. MELLING M255HV294S is listed in this group.

Standard Replacement: 2 parts, from MELLING and SEALED POWER. A representative part number is MELLING M255294S.

Part numbers include MELLING M255HV294S, MELLING M255294S and SEALED POWER 22443621.

This table covers the pistons that travel in each cylinder. Typical signs include knock, blow-by, or a cylinder that will not hold compression. Piston work is a short-block job. Match bore, pin and ring pack in the notes — not the photo. Read more

3 Piston parts are listed for the 2003 Hummer H1, from MAHLE / CLEVITE and ENGINETECH.

The Premium section lists 2 options from MAHLE / CLEVITE — a step above OE specification in materials, tolerances or warranty terms. MAHLE / CLEVITE 2242897 is listed in this group.

The Standard Replacement section: 1 option from ENGINETECH. ENGINETECH P3054 is listed in this group.

This group includes MAHLE / CLEVITE 2242897, MAHLE / CLEVITE 2242897WR and ENGINETECH P3054.

This table covers the Piston Pin bushings. Typical signs include a clunk over bumps, or a torn or walked-out bushing you can see. Press the new bushing square. A cocked bushing will tear in a few thousand miles. Read more

This group shows a single part: ENGINETECH EB0038.

This table covers the rings that seal each piston to the cylinder wall. Read more

6 Piston Ring parts are listed for the 2003 Hummer H1, from MAHLE / CLEVITE, HASTINGS MANUFACTURING, ENGINETECH and 1 other brand. ENGINETECH S40518 carries the "Popular" badge.

The Premium section: 4 options from MAHLE / CLEVITE, ENGINETECH and SEALED POWER. ENGINETECH S40518 is listed in this group.

The Standard Replacement section: 2 options from HASTINGS MANUFACTURING. HASTINGS MANUFACTURING 2D4744 is listed in this group.

Part numbers include ENGINETECH S40518, MAHLE / CLEVITE S41718 and MAHLE / CLEVITE 41718, among others listed above.

This table covers the pushrods that transfer lifter motion to the rocker arms. Read more

One part is listed for the 2003 Hummer H1 — SBI 1901500.

This table covers the Re-Ring kits. Read more

This group shows a single part: ENGINETECH RMC395P.

This table covers the rocker arms that transfer cam motion to the valves. Read more

This group shows a single part: SBI 1801292.

This table covers the Rocker Arm Oil plugs. Typical signs include a leak at the drain or glow-plug hole, or a plug that has rounded off. Replace the crush washer and torque to the spec in the notes. Read more

This group shows a single part: PIONEER RM415.

This table covers the Rocker Arm retainers. Read more

This group shows a single part: MELLING MRM1948.

This table covers the timing chains that keep the cams in time with the crank. Read more

One part is listed for the 2003 Hummer H1 — MELLING 181.

This table covers kits that group a timing chain with the related tensioners and guides. Read more

2 Timing Chain & Component Kit parts for the 2003 Hummer H1 come from 2 brands — ENGINETECH and MELLING.

Part numbers include ENGINETECH TS181A and MELLING 3181SA.

This table covers the gaskets that seal the Timing Cover. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

5 Timing Cover Gasket parts for the 2003 Hummer H1 come from 5 brands — FEL-PRO, APEX, MAHLE / CLEVITE and 2 other brands. The "Popular" part is FEL-PRO TCS45554.

This group includes FEL-PRO TCS45554, APEX ATC3910 and MAHLE / CLEVITE JV971 and the remaining parts above.

This table covers the Timing gears. Read more

One part is listed for the 2003 Hummer H1 — MELLING 2823.

This table covers the turbochargers that compress intake air. Read more

This group shows a single part: ROTOMASTER J1650107N.

This table covers the Turbocharger cartridges. Read more

One part is listed for the 2003 Hummer H1 — ROTOMASTER J1650203N.

This table covers the gaskets that seal the Turbocharger. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

10 Turbocharger Gasket parts are listed for the 2003 Hummer H1, from FEL-PRO, MAHLE / CLEVITE, VICTOR REINZ and 1 other brand. FEL-PRO 61717 carries the "Popular" badge.

This table covers the Turbocharger service kits. Read more

One part is listed for the 2003 Hummer H1 — ROTOMASTER J1060307N.

This table covers the Valve covers. Read more

3 Valve Cover parts are listed for the 2003 Hummer H1, from AUTOTECNICA, DORMAN and SKP.

This group includes AUTOTECNICA GM1419527, DORMAN 264986 and SKP SK264986.

This table covers the gaskets that seal the valve cover to the cylinder head. Typical signs include seepage at the joint, a burnt-oil smell, or a leak that appears only after a long drive. Clean both flanges and torque in the sequence the notes or the manual call for. Read more

5 Valve Cover Gasket parts for the 2003 Hummer H1 come from 5 brands — FEL-PRO, APEX, MAHLE / CLEVITE and 2 other brands. The "Popular" part is FEL-PRO VS50228C.

Listed part numbers: FEL-PRO VS50228C, APEX AVC391 and MAHLE / CLEVITE VS38327, plus the other parts above.

This table covers the pressed-in bronze and cast-iron guides that align valve stems. Typical signs include oil smoke on startup, a guide that has gone oval, or a valve that no longer seats quietly. Guides are a machine-shop fit. Confirm stem diameter in the notes before ordering. Read more

4 Valve Guide parts for the 2003 Hummer H1 come from 3 brands — SBI, ENGINETECH and QUALCAST.

Part numbers include ENGINETECH GD9716, QUALCAST 309715 and SBI 1409715, among others listed above.

This table covers the lifters / tappets that transfer cam motion to the valves. Read more

4 Valve Lifter parts for the 2003 Hummer H1 come from 4 brands — ENGINETECH, MELLING, QUALCAST and 1 other brand.

This group includes ENGINETECH L2104, MELLING JB2104 and QUALCAST 362104 and the remaining parts above.

This table covers the rotators that turn each valve as it operates. Read more

One part is listed for the 2003 Hummer H1 — QUALCAST 374003.

This table covers the Valve seats. Read more

7 Valve Seat parts are listed for the 2003 Hummer H1, from ENGINETECH, QUALCAST, SBI and 1 other brand. ENGINETECH ST193723 carries the "Popular" badge.

This group includes ENGINETECH ST193723, ENGINETECH ST156236N and DURA-BOND 70840 and the remaining parts above.

This table covers the springs that close each intake and exhaust valve. Typical signs include a sagging corner, a broken coil, or a clunk from the spring pocket. Replace springs in axle pairs and inspect the seats. Read more

2 Valve Spring parts are listed for the 2003 Hummer H1, from QUALCAST and SBI.

Part numbers include QUALCAST 321220D and SBI 1601233.

This table covers the Valve Spring retainers. Read more

SBI supplies both parts for the 2003 Hummer H1.

Listed part numbers: SBI 1611012 and SBI RC157.

This table covers the keepers that lock each valve-spring retainer to the stem. Read more

2 Valve Spring Retainer Keeper parts are listed for the 2003 Hummer H1, from QUALCAST and SBI.

Part numbers include QUALCAST 34555 and SBI 1211003.

This table covers the seals on each valve stem that control oil into the guides. Typical signs include a wet housing, a drip after sitting, or fluid flung off a rotating shaft. Fix the surface the seal rides on. A new seal on a grooved shaft will leak again. Read more

14 Valve Stem Seal parts for the 2003 Hummer H1 come from 7 brands — QUALCAST, FEL-PRO, SBI and 4 other brands. The "Popular" part is ENGINETECH SG65V.