INTAKE/EXHAUST SYSTEM 7 C TURBOCHARGER

Transcription

1 INTAKE/EXHAUST SYSTEM 7 C TURBOCHARGER

2 Table Of Contents Page Identification C-1 Torque Specifications C-1 Sealants C-1 Turbocharger Specifications C-1 Description C-2 Turbocharger C-2 Wastegate C-2 Exploded Views C-3 Turbocharger And Related Components C-3 Boost Pressure Control (Wastegate) Components C-4 Turbocharger C-5 Testing Turbocharger Boost Pressure C-5 Checking Turbine Bearings (Assembled) C-5 Removal C-6 Removing Exhaust Elbow C-6 Removing Turbocharger Unit C-7 Disassembly C-8 Cleaning C-9 Inspection C-9 Axial (End) Play Measuring C-9 Radial (Side) Play Measuring C-10 Assembly C-10 Installation C-11 Boost Pressure Control (D254 Engines) C-16 Exhaust Pipe C-16 Inspection C-16 Removal C-17 Installation C-17 Valve C-18 Removal C-18 Installation C-18 Wastegate C-19 Removal C-19 Installation C-19 7C-0 TURBOCHARGER

3 Identification Torque Specifications DESCRIPTION Lb. Ft. N m Turbocharger Mounting Nuts Clamping Plate Nuts or Screws Wastegate-to-Exhaust Manifold Mounting Nuts (D4.2L/220) Valve-to-Wastegate Screws (D4.2L/220) Tighten Securely (Equally, in a diagonal pattern.) a - Identification Number Location Sealants Loctite Gasket Sealer Turbocharger Specifications Model D3.0L/150 D3.6L/180 D4.2L/220 Manufacturer KKK Kuhnle, Kopp and Kaush Part KKK K GA K GA K MNA 8.72 Number Quicksilver Maximum turbine shaft axial (end) play.0059 in. (0.15 mm) Maximum turbine shaft radial (side) play.0165 in. (0.42 mm) Maximum Boost psi (82.7 to kpa) at 3800 RPM psi ( kpa) at 3600 RPM Engine RPM when boost starts Wastegate NO YES TURBOCHARGER 7C-1

4 Description Turbocharger All diesel engines covered in this manual are equipped with a turbocharger to boost intake pressure resulting in increased horsepower. In one casing on the turbocharger housing exhaust gases are used to spin the turbine up to 100,000 RPM. The compressor, which is installed on the same shaft but in a separate casing, draws in filtered air, compresses it, and delivers it to the engine through an intake duct and intercooler. The turbo bearings are lubricated by engine oil. Coolant from the engine s closed cooling system cools the turbocharger housing, while the exhaust elbow is cooled by seawater flowing through it from the seawater system. On D3.0L/150 and D3.6L/180 Engines: Turbo pressure, or boost, is limited by engine RPM. On D4.2L/220 Engines: Turbo pressure is limited by a boost pressure control valve (commonly called a wastegate ) is mounted on the combined exhaust/intake manifold. Wastegate When used in combination with the turbocharger (on the D4.2L/220 engines only) a higher torque output even at low engine speeds is obtained and allows the engine a wider operating speed range. The function of the wastegate is to limit the boost pressure generated by the turbocharger within a controlled tolerance band. When factory set boost pressure is exceeded, the valve opens and bypasses a part of the exhaust gas flow around the turbine. The resulting reduced mass-flow produces a lower power output. The compressor output is reduced in proportion and the boost pressure falls to the predetermined level. This control process is repeated for each change in engine load. This allows the use of a smaller turbocharger turbine which provides better acceleration and torque, as boost comes on more rapidly and turbo lag is reduced. 7C-2 TURBOCHARGER

5 Exploded Views Turbocharger And Related Components a Turbocharger 2 - Gasket 3 - Clamp 4 - Gasket 5 - Exhaust Elbow, or Riser (Not Shown) 6 - Oil Drain Pipe 7 - Double Banjo Bolt with Sealing Washer 8 - Coolant Vent Hose (Connection shown as dashed line.) 9 - Hose Fittings, At Water Manifold 10- Hose Fitting for Hose to Heat Exchanger 11- Turbocharger-to-Intake Duct Hose 12- Oil Feed Pipe 13- Gasket 14- Turbocharger Support Bracket 15- Spacer 16- O-Ring Seals Torque Specifications a 18 lb. ft. (24 N m) - To Heat Exchanger TURBOCHARGER 7C-3

6 Boost Pressure Control (Wastegate) Components Typical MCM (Stern Drive) D4.2L/220 Components Shown - [MIE (Inboard) Similar] a Wastegate 2 - Wastegate-to-Exhaust Manifold Gasket 3 - Wastegate Exhaust Pipe, MCM Shown (MIE Similar) 4 - Gasket (2) 5 - Hex Nut and Lockwasher (4) 6 - Heat Shield Blanket (For Exhaust Pipe) 7 - Boost Pressure Valve 8 - Boost Pressure Line 9 - Banjo Bolt and Sealing Washers (at Exhaust Manifold) 10- Banjo Bolt and Sealing Washers (at Valve)) Torque Specifications a 18 lb. ft. (24 N m) 7C-4 TURBOCHARGER

7 IMPORTANT: Before suspecting the turbocharger for engine running problems, the fuel injection system and engine mechanicals (valves, camshaft, etc.) must be in good working order. Turbocharger Testing Turbocharger Boost Pressure! CAUTION Safety glasses, gloves and protective clothing should be worn while testing turbocharger boost pressure, to protect against pressurized air being released by a leak or rupture of a hose which could cause injury. The following should be observed prior to testing: Engine should be at normal operating temperature. Engine air cleaner should be clean (or replaced if not clean). 1. Remove plug (screw with sealing washer) from intercooler housing as shown. a On D3.0L/150 and D3.6L/180 Engines: Maximum boost should be between psi ( kpa) at 3800 RPM. On D4.2L/220 Engines: Maximum boost should be between psi ( kpa) at 3600 RPM. Readings LOWER than specified above indicate possible turbocharger problem(s), or boost pressure control system problems (D4.2L/220 engines only), IF no engine problem exists, such as incorrect valve clearance or a blockage in the exhaust system (refer to appropriate Sections in this manual, including Troubleshooting ). NO boost pressure would indicate a faulty turbocharger requiring replacement. Checking Turbine Bearings (Assembled) 1. Refer to the following section Turbocharger - Removal and remove exhaust elbow as outlined for your engine. 2. Rotate the turbine impeller by hand to see that it turns smoothly. If not, turbine bearings or impeller problems exist. 3. Using a feeler gauge as shown, check clearance between turbine blades and housing at two locations opposite one another. The difference in the two readings is the radial play. Maximum radial play is.0165 in. (0.42mm). b a - Plug (Screw with Sealing Washer) b - Intercooler Housing Typical 2. Install a 0-25 psi ( kpa) pressure gauge into intercooler where plug was removed in Step Start engine and watch pressure gauge. Checking Turbine Blade Clearance Check if turbine blades are rubbing on housing. Replace turbocharger if so TURBOCHARGER 7C-5

8 Removal! WARNING Always disconnect battery cables from battery before working around electrical system components to prevent injury to yourself or damage to electrical system. REMOVING EXHAUST ELBOW 1. Disconnect battery cables from battery terminals. 2. Loosen hose clamp and disconnect seawater hose at turbocharger exhaust elbow or riser. Drain seawater into a suitable container. 4. Follow instructions a or b : a. On D3.0L/150 and D3.6L/180 Engines: Proceed to Step 5. b. On D4.2L/220 Engines: (1) Loosen spring retaining heat-shield blanket around wastegate exhaust pipe. (2) Remove fasteners and lockwashers retaining wastegate exhaust pipe to exhaust elbow a - Hose Clamp b - Seawater Hose Typical 3. Loosen exhaust elbow hose clamps as shown. b a - Spring (Blanket Retainer) b - Blanket, Heat-Shield c - Hex Nuts With Lockwashers d - Wastegate Exhaust Pipe Typical Suitably mark exhaust elbow, or riser, and turbocharger housing for alignment during reassembly. a c a - Hose Clamps b - Exhaust Elbow or Riser c - Exhaust Hose MCM D4.2L/220 With Riser Shown (All Similar) 7C-6 TURBOCHARGER

9 6. Loosen exhaust elbow, or riser, clamp. Remove elbow gasket and clamp. c 3. Remove oil feed pipe and banjo bolt from coolant vent pipe at turbocharger as shown. Loosen air filter and turbocharger-to-intake duct hose clamps a c b a - Clamp b - Exhaust Elbow c - Exhaust Gasket (Not Shown) Typical Exhaust Elbow Shown (Similar With Riser) REMOVING TURBOCHARGER UNIT a - Turbocharger-to-Intake Duct Hose Clamp b - Oil Feed Pipe c - Banjo Bolt (With Sealing Washers), Coolant Vent Line d - Air Filter Hose Clamp Typical Shown (All Similar) Remove oil drain pipe on bottom of turbocharger as shown. 1. Refer to SECTION 6B - Closed Cooling System, Draining Coolant and drain closed cooling system. 2. Remove lifting eye bracket as shown to gain access to turbocharger mounting nuts a - Bracket, Lifting Eye b - Screws Typical Shown a - Oil Drain Pipe b - Hex Nuts With Lockwashers TURBOCHARGER 7C-7

10 5. To gain access to turbocharger mounting nuts, follow instructions a or b : a. On D3.0L/150 and D3.6L/180 Engines: Remove intake duct from side of intercooler housing. (Refer to SECTION 7A - Intercooler, for instructions on removal.) b. On D254 Engines: Remove intake duct from rear of intercooler housing. (Refer to SEC- TION 7A - Intercooler, for instructions on removal.) IMPORTANT: In the event that turbocharger mounting nuts are corroded, or otherwise resist loosening in the following, it may become necessary to completely remove the intercooler housing to gain a more suitable access to mounting nuts. Refer to SECTION 7A - Intercooler, for instructions on removal and installation of the intercooler housing. 6. Remove four mounting nuts retaining turbocharger to exhaust manifold. 7. Remove the two support bracket mounting screws as shown, and MerCathode controller bracket if so equipped (not shown in the following). Remove turbocharger unit. a - Support Bracket b - Screw (2) With Washer c - MerCathode Controller Bracket Location c Disassembly 1. Make matching marks on the exhaust housing and bearing housing to aid alignment in reassembly. 2. Remove 6 hex nuts or hex screws and the 3 clamping plates shown. a - Mounting Nuts (4 Total, Two Hidden In This View) Typical Shown (All Similar) a - Matching Marks b - Hex Nuts or Hex Screws (6 Total - 2 Hidden In This View) c - Clamping Plates (3 Total - One Hidden In This View) d - Exhaust Housing e - Bearing Housing Typical Turbocharger Shown 7C-8 TURBOCHARGER

11 NOTE: If the exhaust housing cannot easily be removed by hand, tap on it carefully all around using a plastic hammer and carefully remove it in the following. IMPORTANT: Be careful not to damage the turbine impeller when removing exhaust housing. 3. Remove exhaust housing as shown. Cleaning IMPORTANT: Never use a caustic cleaning solution, as it may attack aluminum. Also, never use a wire brush which could damage impeller or mating surfaces. 1. BEFORE cleaning inspect the disassembled parts for burning, abrasion, carbon deposits, gas and oil leakage.! CAUTION Always wear safety glasses when using compressed air to protect from hose rupturing or flying debris.! WARNING When using compressed air to dry components, DO NOT spin turbine, or allow turbine to spin, since no oil is being provided to the bearings and could result in damage to the bearings. a - Exhaust Housing b - Bearing Housing c - Turbine Impeller Typical Turbocharger Shown 4. Inspect turbine blades. If blades are rubbing against housing, the bearings are worn. Replace turbocharger. 2. Thoroughly clean all the parts with clean diesel fuel, using a soft brush. Dry with compressed air. Inspection IMPORTANT: If turbine shaft bearing axial or radial play is excessive, replace turbocharger. AXIAL (END) PLAY MEASURING 1. With turbocharger held in vise, attach dial indicator as shown following. 2. Move turbine shaft in direction shown. Maximum axial play (end play) is.0059 in. (0.15mm) a - Turbine b - Inspect (Edges of Blades) Measuring Axial (End) Play TURBOCHARGER 7C-9

12 RADIAL (SIDE) PLAY MEASURING 1. With turbocharger held in vise, attach dial indicator as shown in following. 2. Move turbine shaft in direction shown. Maximum radial (side) play is.0165 in. (0.42mm). 2. Follow instructions a or b : a. On D3.0L/150 and D3.6L/180 Engines: (1) Being certain surfaces are clean of old gasket material or debris, install a new gasket on bearing housing oil drain/ spacer flange. (2) Assemble spacer with bracket attached as shown. Tighten hex nuts finger tight at this time Measuring Radial (Side) Play Assembly IMPORTANT: When installing a new turbocharger, it may be necessary to turn intake, bearing, and/or exhaust housings to allow mounting bracket to be bolted to engine. 1. While aligning matching marks, assemble exhaust housing and bearing housing together. Install clamping plates and finger tighten hex nuts or screws. Do not tighten securely at this time a - Gasket b - Spacer c - Support Bracket d - Hex Nut a - Matching Marks b - Exhaust Housing c - Bearing Housing d - Clamping Plates (3 Total - One Hidden In This View) e - Hex Nuts or Hex Screws (6 Total - Two Hidden In This View) Typical Turbocharger Shown C-10 TURBOCHARGER

13 b. On D4.2L/220 Engines: (1) Being certain surfaces are clean, install a new O-ring in groove of drain/spacer flange where it meets bearing housing of turbocharger. (2) Assemble spacer with bracket attached as shown. Tighten hex nuts finger tight at this time. Installation IMPORTANT: When installing turbocharger, it may be necessary to turn intake and exhaust housings to line up with intake air duct and exhaust manifolds on engine. 1. Using a new gasket, install turbocharger on exhaust manifold as shown. Tighten nuts to 18 lb. ft. (24 N m) a - Gasket, Exhaust Manifold-to-Turbocharger b - Nut (4 Total - Two Hidden In This View) Typical Turbocharger Shown 2. Install support bracket screws with washers as shown (and MerCathode controller with bracket if so equipped - not shown following). Tighten screws securely a - O-ring (Hidden In Assembled View) b - Spacer (Oil Drain) c - Support Bracket d - Hex Nut 3. Position exhaust housing and bearing housing (with intake housing) as shown. a - Exhaust Housing b - Bearing Housing (With Intake Housing) a - Screws With Washers b - Support Bracket Typical Tighten the six hex nuts or hex screws (on D4.2L) on clamping plates of exhaust housing-to-bearing housing to 22 lb. ft. (30 N m). (Refer to Step 1 in Assembly section, for location.) TURBOCHARGER 7C-11

14 4. Follow instructions a or b : a. On D3.0L/150 and D3.6L/180 Engines: Remove hex nuts from spacer (previously installed finger tight). Using a new gasket, install drain pipe. Tighten hex nuts securely. 5. Follow instructions a - d : a. Using new sealing washers on banjo bolt, install coolant vent line to turbocharger exhaust housing as shown. Tighten banjo bolt securely. b. Clean sealing surfaces and using a new gasket, install oil feed pipe as shown. Tighten screws securely. c. Install turbocharger-to-intake duct hose as shown. Tighten hose clamp at turbocharger securely. d. Fit air filter to turbocharger and tighten clamp securely a - Spacer b - Hex Nuts c - Gasket d - Oil Drain Pipe b. On D4.2L/220 Engines: Remove hex nuts from spacer (previously installed finger tight). Using a new O-ring positioned in spacer groove, install drain pipe. Tighten hex nuts with lockwashers securely. h a - Sealing Washers b - Banjo Bolt c - Coolant Vent Line d - Turbocharger Exhaust Housing e - Gasket f - Oil Feed Pipe g - Screw (2) h - Air Filter i - Hose Clamp Typical Shown (All Similar) a - Spacer b - Hex Nuts c - O-ring (Hidden In One View) d - Oil Drain Pipe 7C-12 TURBOCHARGER

15 IMPORTANT: If it became necessary to remove the entire intercooler housing from the intake/exhaust manifold during disassembly (to gain better access to turbocharger mounting nuts) refer to Section 7A - Intake Manifold/Intercooler, at this time for proper installation. 6. If previously only the intake duct of intercooler was removed, follow instructions a or b : a. On D3.0L/150 and D3.6L/180 Engines: (1) Clean sealing flanges of intercooler housing and intake duct. Do not nick or gouge the surfaces. (2) Apply Loctite 514 sealer to intake duct flange as shown. (2) Apply Loctite 514 sealer to intake duct flange on intercooler as shown a - Intake Duct b - Flange (Apply Sealer Here) (3) Install intake duct on intercooler as shown. Torque allen-head screws with wave washers to 7 lb. ft. (10 N m). a - Intercooler Housing b - Intake Duct c - Flange (Apply Sealer Here) (3) Install intake duct on intercooler as shown. Torque four allen-head screws with wave washers to 7 lb. ft. (10 N m). NOTE: Intercooler shown removed for visual clarity only a - Intake Duct b - Intercooler Housing c - Screws With Wave Washers D3.6L/180 Shown (D3.0L/150 Similar) b. On D4.2L/220 Engines: (1) Clean sealing flanges of intercooler housing and intake duct. Do not nick or gouge the surfaces. a - Intake Duct b - Intercooler Housing c - Screw With Wave Washer TURBOCHARGER 7C-13

16 7. Install lifting eye bracket as shown. Tighten screws securely. (2) Install seawater hose to exhaust elbow, or exhaust riser fitting, if so equipped. Tighten hose clamps securely. (3) Position exhaust hose on elbow, or riser. Tighten hose clamps securely. c d b a - Bracket, Lifting Eye b - Screws With Washers Typical Shown 8. As shown, tighten turbocharger-to-intake duct hose clamp securely c a d e b h f g a - Hose b - Hose Clamp c - Turbocharger d - Intake Duct 9. Follow instructions a or b : a. On D3.0L/150 and D3.6L/180 Engines: (1) Using a new gasket, install exhaust elbow, or exhaust riser if so equipped, as shown. Align with exhaust pipe. Tighten elbow or riser clamp securely. a - Gasket b - Exhaust Elbow c - Exhaust Elbow, or Riser, Clamp d - Seawater Hose and Clamp (At Exhaust Elbow or Riser) e - Exhaust Riser f - Exhaust Hose g - Exhaust Hose Clamp (4) h - Exhaust Pipe Typical Installations Shown 7C-14 TURBOCHARGER

17 b. On D4.2L/220 Engines: (1) Install exhaust elbow, or riser, using new gaskets on exhaust elbow and wastegate exhaust pipe flange as shown, Align studs on elbow, or riser, with holes in wastegate exhaust pipe. Simultaneously, align with exhaust pipe. Tighten exhaust elbow clamp securely. (2) Install hex nuts and washers, or screws and washers, on wastegate exhaust pipe. Tighten fasteners securely and wrap with heat shield blanket. Fasten spring to retain blanket. (3) Install seawater hose from fluid cooler-toexhaust elbow, or riser if so equipped. Tighten hose clamp securely. (4) Position exhaust hose as shown. Tighten hose clamps securely. ce d a b e c eg f a - Gasket, Exhaust Elbow b - Gasket, Wastegate Exhaust Pipe-to-Elbow, or Riser c - Exhaust Elbow d - Wastegate Exhaust Pipe e - Clamp, Exhaust Elbow f - Hex Nut g - Blanket, Heat Shield h - Spring Early MCM D4.2L/220 Shown (Similar With Riser, or On MIE Models) a - Exhaust Riser b - Exhaust Elbow c - Seawater Hose (Fluid Cooler-to-Exhaust Elbow) d - Seawater Hose (Fluid Cooler-to-Exhaust Riser) e - Clamp, Seawater Hose f - Exhaust Hose g - Clamp(s), Exhaust Hose Early MCM D4.2L/220 Shown, With Inset of Riser Connection (All Connections Similar On MIE Models) TURBOCHARGER 7C-15

18 10. Fill closed cooling system at this time according to instructions in Section 6B - Closed Cooling System, Filling Closed Cooling System. 11. Connect battery cables to battery by FIRST installing positive (+) battery cable end on positive (+) battery terminal. Tighten clamp securely. THEN install negative ( ) battery cable end on negative ( ) battery terminal. Tighten clamp securely. 12. Pre-lubricate turbocharger by turning ignition switch to the ON position and depressing both START and STOP buttons TOGETHER, turning the engine over without starting it. DO NOT engage starter for more than 15 seconds at one time. Allow at least one minute for starter to cool before reusing. Crank engine intermittently until oil pressure registers on oil gauge. 13. Start engine and check for leaks. 14. Test turbocharger boost pressure as previously outlined. Exhaust Pipe INSPECTION 1. Loosen spring retaining heat shield blanket around wastegate exhaust pipe as shown. Boost Pressure Control (D254 Engines)! WARNING Always disconnect battery cables from battery before working around electrical system components to prevent injury to yourself or damage to electrical system. a - Retaining Spring b - Blanket, Heat Shield c - Wastegate Exhaust Pipe d - Gasket Typical MCM Assembly Shown (MIE Similar) Visually examine pipe and convolutions for signs of cracking or leakage. Also, examine gaskets for signs of leakage. Repair as needed. (Refer to Removal if required.) 7C-16 TURBOCHARGER

19 REMOVAL 1. Refer to Removing Exhaust Elbow as previously outlined and remove exhaust elbow. 2. Remove two remaining hex nuts, or screws, and lockwashers on wastegate exhaust pipe as shown. 3. Using hex nuts or screws, with lockwashers, install wastegate exhaust pipe as shown. Tighten fasteners securely. a - Hex Nut or Screws, With Lockwashers (2) b - Wastegate Exhaust Pipe c - Wastegate Typical MCM Pipe Shown (MIE Similar) 3. Remove wastegate exhaust pipe a - Gasket b - Wastegate Exhaust Pipe c - Hex Nuts With Lockwashers Typical MCM Pipe Shown (MIE Similar) Install turbocharger exhaust elbow. (Refer to Turbocharger - Installation as previously outlined, and accomplish appropriate instructions regarding installation of exhaust elbow or riser.) INSTALLATION 1. Clean old gasket material from wastegate mating surfaces and pipe (if to be reused), being careful not to distort pipe or crack it. Do not allow debris to enter wastegate opening. 2. Install new gasket on wastegate flange TURBOCHARGER 7C-17

20 Valve REMOVAL 1. Follow instructions a - c : a. Remove banjo bolt with sealing washers (2) from pressure line on bottom of intercooler housing as shown. b. Remove banjo bolt with sealing washers (2) from pressure line on valve as shown. c. Remove pressure line. 2. Remove allen-head screws and washers retaining valve to wastegate. Remove valve a - Allen-Head Screws With Washers (3 Total - Two Hidden In This View) b - Valve c - Wastegate Typical a - Banjo Bolts b - Sealing Washers (2 Each) c - Pressure Line d - Intercooler Housing e - Wastegate f - Valve Typical INSTALLATION 1. Position pressure line fitting on valve toward front of engine and install on wastegate using allenhead screws and washers. In equal amounts, tighten screws securely. 2. Install pressure line on valve using banjo bolt with new sealing washers. Finger tighten. 3. Install banjo bolt with new sealing washers on pressure line at exhaust manifold. Finger tighten. 4. Tighten both banjo bolts securely. Do not overtighten. 5. Pre-lubricate turbocharger and engine. To do this, move the STOP switch toggle lever DOWN and hold in this position while you turn the key switch to START position. Doing this TOGETH- ER turns the engine without starting it. DO NOT engage starter for more than 15 seconds; allow at least one minute cool down time before re-engaging starter for another 15 seconds. Watch that starter does not overheat. 6. Start engine and check for leaks. 7. Test turbocharger boost pressure as previously outlined. 7C-18 TURBOCHARGER

21 Wastegate REMOVAL 1. Remove the following, as previously outlined: Exhaust elbow Wastegate exhaust pipe Wastegate valve 2. Remove the four fasteners with lockwashers retaining wastegate to exhaust manifold as shown. INSTALLATION 1. Clean all traces of old gasket material from exhaust manifold flange where shown Clean old gasket material from wastegate and using a new gasket install wastegate on exhaust manifold as shown. Tighten the four fasteners with lockwashers securely a - Hex Nuts, or Screws, With Lockwashers (4) b - Wastegate c - Exhaust Manifold Typical c a - Wastegate b - Gasket c - Hex Nuts, or Screws, With Lockwashers (4 Total) Typical TURBOCHARGER 7C-19

22 3. Following instructions previously outlined, install: Wastegate valve Wastegate exhaust pipe Exhaust elbow or riser 4. Pre-lubricate turbocharger and engine. To do this, move the STOP switch toggle lever DOWN and hold in this position while you turn the key switch to START position. Doing this TOGETHER turns the engine without starting it. DO NOT engage starter for more than 15 seconds; allow at least one minute cool down time before re-engaging starter for another 15 seconds. Watch that starter does not overheat. 5. Start engine and check for leaks. 6. Test turbocharger boost pressure as previously outlined. 7C-20 TURBOCHARGER