These engines are not easy to service and this quite often needs a number of tools. Since the
Timing Chains must be treated delicately, any occurrence that entails their modification is complex and disassembling may cause severe damage to the engine. As an interference engine design, a faulty timing chain forces valve and potentially piston interference and requires removal of cylinder heads. The timing system is challenging and errors can be costly, involving major engine failure; due to the complexity of this repair, only skilled personnel should attempt this, and all work carried out should be cross checked before starting the engine. Some of the om4601 series turbocharged models with DI have very high fuel rail pressure, and fuel pressure release procedures must be observed before working on any high pressure fuel system. In the automobile industry, durability is now an important aspect that most car producers pay great attention to; all of the 3.5L and 3.7L Duratec engines feature solid tappets; in contrast, the 2.7L EcoBoost engines contain roller followers and hydraulic lash adjusters. Before performing the removal of the camshafts, what is needed is to lift the vehicle off the ground securely, release fuel pressure, and or remove the negative terminal of the battery. When pulling both camshafts from both sides, the side must be pulled right firstly and then left; and in any case timing chains and corresponding camshaft VCT units should be withdrawn gently. Front camshaft mega-cap has to be unmounted first to prevent the damage to the engine and all caps must be put in their respective place. Removal of the camshafts enables one to pull the lifters by the use of a magnet and these should be placed in another container which should preferably be marked for easy identification when assembling. Camshafts are also meant be cleaned, inspected for further wear or damage and then the bearing journals and camshaft lobe heights are to be measured. Lash adjusters shall be lubricated and fitted back to their starting positions and camshafts required to be correctly placed before the caps and bolts are tightened in pairs. The valve clearances are to be inspected and set and the subsequently the installation of VCT units and timing chains. At last the cooling system should be filled again and the oil should be changed before starting the engine.