start Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 The decision to repair an engine should be based on all the information about the engine that is available to the service technician In some cases, the engine might not be worth repairing It is the responsibility of the technician to discuss the advantages and disadvantages of the different repair options with the customer Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 OBJECTIVES: After studying Chapter 25, the reader should be able to: • • • • Prepare for ASE Engine Repair (A1) certification test content area “A” (General Engine Diagnosis) Describe how to remove an engine from a vehicle Discuss how to remove cylinder heads without causing warpage List the steps necessary to remove a piston from a cylinder Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 OBJECTIVES: After studying Chapter 25, the reader should be able to: • • • • Explain how to remove a valve from a cylinder head List the types of engine cleaning methods List the various methods that can be used to check engine parts for cracks Describe crack-repair procedures Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 KEY TERMS: acid materials • agitation • aqueous-based solutions caustic materials • fogging oil • fusible link harmonic balancer • hydroseal • keepers • pH • putty knife • pyrolytic soluble • stop drilling ultrasonic cleaning valve locks • vibration damper • Zyglo Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman ® ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 ENGINE REMOVAL The engine exterior and compartment should be cleaned before work is begun A clean engine is easier to work on, keeps dirt out of the engine and minimizes damage from slipping tools The battery ground cable is disconnected or the battery is removed the from the vehicle Working on the top of the engine is easier if the hood is removed The hood is usually stored on fender covers placed on the top of the vehicle, where it is least likely to be damaged NOTE: Most technicians lightly scribe around the hood hinges prior to removal to make aligning the hood easier during reinstallation Coolant is drained from the radiator and block The exhaust manifold is disconnected Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman Continued ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 HINT: On some engines, it is easier to remove the exhaust pipe from the manifold On others, it is easier to separate the exhaust manifold from the head and leave the manifold attached to the exhaust pipe On V-type engines, the intake manifold must be removed before the heads can be taken off Wires, accessories, hoses, and tubing must be removed before the head can be removed A Picture Is Worth a Thousand Words Take pictures of the engine being serviced with a digital or video camera These pictures will be worth their weight in gold when it comes time to reassemble or reinstall the engine It is very difficult for anyone to remember the exact location of every bracket, wire, and hose Referring back to the photos of the engine before work was started will help you restore the vehicle to like-new condition Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 All coolant hoses are removed, and the transmission oil cooler lines are disconnected from the radiator Radiator mounting bolts are removed, and the radiator lifted from the engine compartment The air-conditioning compressor can usually be separated from the engine, leaving all air-conditioning hoses securely connected to the compressor and lines If necessary to disconnect air-conditioning lines, recover refrigerant Air-conditioning lines should be plugged immediately to keep out moisture, and remain plugged until just prior to reassembly Under the vehicle, the drive shaft (propeller shaft) or half shafts are removed and exhaust pipes disconnected It may be necessary to loosen the steering linkage idler arm to give clearance Clutch linkage, transmission controls, and speedometer cable wiring, are disconnected and tagged Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 A sling, either a chain or lift cable, is attached to the engine There are two ways to remove the engine: The engine can be lifted out of the chassis with the transmission/ transaxle attached The transmission/transaxle can be disconnected from the engine and left in the chassis HINT: For the best results, use the factory-installed lifting hooks that are attached to the engine These hooks were used in the assembly plant to install the engine and are usually in the best location to remove the engine A hoist is attached to the sling and snugged to the weight This leaves the engine resting on the mounts The rear cross-member is removed, and on rear-wheel-drive vehicles, the transmission is lowered The hoist is tightened to lift the engine Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 The engine will have to nose up as it is removed, and the front of the engine must come almost straight up as the transmission slides from under the floor pan, as illustrated here The engine and transmission are hoisted free, swung clear, and lowered onto an open floor area Figure 25–1 An engine must be tipped as it is pulled from the chassis Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman Continued 10 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 CRACK-WELDING ALUMINUM Cracks in aluminum can be welded using a Heli-arc® or similar welder that is specially designed to weld aluminum The crack should be cut or burned out before welding begins The old valve-seat insert should be removed if the crack is in or near the combustion chamber Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 58 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 CRACK-PLUGGING In the process of crack plugging, a crack is closed using interlocking tapered plugs This can be performed to repair both aluminum and cast-iron engine components The ends of the crack are center-punched and drilled with the proper size tap drill for the plugs The hole is reamed with a tapered reamer and tapped to give full threads Figure 25–26 Reaming a hole for a tapered plug Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman Continued 59 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 Figure 25–27 Tapping a tapered hole for a plug Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 60 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 The plug is coated with sealer; then it is tightened into the hole, sawed about one-fourth of the way through, and broken off The saw slot controls the breaking point Figure 25–28 Screwing a tapered plug in the hole If the plug breaks off below the surface, it will have to be drilled out and a new plug installed The plug should go to the full depth or thickness of the cast metal Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman Figure 25–29 Cutting the plug with a hacksaw 61 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 After the first plug is installed on each end, a new hole is drilled so that it cuts into the edge of the first plug This new hole is reamed and tapped, and a plug is inserted as before The plug should fit about one-fourth of the way into the first plug to lock it in place Figure 25–30 Interlocking plugs Interlocking plugs are placed along the entire crack, alternating from side to side The exposed ends of are peened over with a hammer to help secure them in place The surface of the plugs is then ground or filed down nearly to the gasket surface Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 62 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 In the combustion chamber and at the ports, the plugs are ground down to the original surface using a hand grinder The gasket surface of the head must be resurfaced after the crack has been repaired Figures 25-31a, b & c show a head repair using plugs Figure 25–31a A hole is drilled and tapped for the plugs Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 63 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 Figure 25–31b The plugs are installed Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 64 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 Figure 25–31c After final machining, the cylinder head can be returned to useful service Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 65 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 PHOTO SEQUENCE Engine Removal Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 66 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 PHOTO SEQUENCE Engine Removal Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman (cont.) 67 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 SUMMARY The factory-installed lifting hooks should be used when hoisting an engine Engine component parts should only be removed when the engine is cold Also, the torque table should always be followed backward, starting with the highest-number head bolt and working toward the lowest-number This procedure helps prevent warpage The ridge at the top of the cylinder should be removed before removing the piston(s) from the cylinder Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 68 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 SUMMARY (cont.) The connecting rod and main bearing caps should be marked before removing to ensure that they can be reinstalled in the exact same location when the engine is reassembled The tip of the valve stem should be filed before removing valves from the cylinder head to help prevent damage to the valve guide Mechanical cleaning with scrapers or wire brushes is used to remove deposits Steel wire brushes should never be used to clean aluminum parts Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 69 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 SUMMARY (cont.) Always use aluminum-safe chemicals when cleaning aluminum parts or components 10 Thermal cleaning is done in a pyrolytic oven in temperatures as high as 800°F (425°C) to turn grease and dirt into harmless ash deposits 11 Blasters use metal shot or glass beads to clean parts All of the metal shot or glass beads must be cleaned from the part so as not to cause engine problems Continued Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 70 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 SUMMARY (cont.) 12 All parts should be checked for cracks using magnetic, dye penetrant, fluorescent-penetrant, or pressure testing methods 13 Cracks can be repaired by welding or by plugging Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 71 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458 end Automotive Technology: Principles, Diagnosis, and Service, 3rd Edition By James D Halderman 72 ©©2008 2009Pearson PearsonEducation, Education,Inc Inc Pearson PearsonPrentice PrenticeHall Hall- -Upper UpperSaddle SaddleRiver, River,NJ NJ07458 07458