Q: How to remove, inspect, and install the cylinder head in DOHC four cylinder engine on 2003 Ford Ranger?
A: If one wants to remove the cylinder head, then he will need to do the following, disconnect the negative battery terminals and drain the cooling system. Subsequently, camshafts and on top of them the fuel rail, including injectors should be unbolted-look at the spacers resting underneath the rail next and, finally, intake and exhaust manifold. Remove the electrical connectors for the engine coolant temperature sender and the EGR valve, which you can find at the back of the cylinder head, then, remove the coupling of the coolant hose to the EGR unit, and another coupling for the cooling system bypass hose. Loosen the cylinder head bolts and then discard all but one for comparison with the new bolts, and then, using excessive care, remove the cylinder head. Before taking off the cylinder head gasket, affix a piece of paper or a sticker to one side so that orientation of the new gasket will be easier; compare the sticker or paper with the new gasket later on. The main mating faces of the cylinder head and block must be sufficiently clean and de-carbonised using a hard plastic or wood scraper which will not harm the aluminum alloy and should not allow any carbon to contaminate the oil and water passages. As a precautionary measure against carbon entering through the water, oil and bolt holes, seal the respective positions with adhesive tape and paper; insert a little grease in the piston bore gap. As for the pistons after each cleaning it is also a mandatory requirement to make sure that there is no grease and carbon left. Examine the mated surfaces for roughness and if it has minor marks, use a file for modification but if the marks are so deep go for a replacement. In case of warpage, verify this with the help of a straight edge. For installation use a small amount of suitable silicone sealent in two areas of the cylinder block The head gasket to be fitted with the suitable side up must be new. The new cylinder head bolts should be lubricated using clean engine oil, installed in the correct position and subsequently tightened by hand after which they should be tightened using the following five steps and in the correct sequence. Refitting includes use of new gaskets and fasteners the manifolds, camshafts and timing chain since they should be tightened to definite torque. Check and ensure that all the hoses and wiring are rightly placed and properly fixed, and the cooling system is full, engine oil and filter is changed, and finally the engine is started and if feels warm it is turned off and checked again for any signs of oil or coolant leakage.