Mercury 7U7Z-6049-AARH Cylinder Head Assembly

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Disconnect the negative cable from the battery.

New cylinder head bolts must be used for reassembly. Failure to use new bolts may result in cylinder head gasket leakage and engine damage. 15. The mating surfaces of the cylinder heads and engine block must be perfectly clean when the cylinder heads are installed. Use a gasket scraper to remove all traces of carbon and old gasket material, then clean the mating surfaces with lacquer thinner or acetone. If there's oil on the mating surfaces when the cylinder heads are installed, the gaskets may not seal correctly and leaks may develop. Cover the open areas of the engine with shop rags to keep debris out during repair and reassembly. Use a vacuum cleaner to remove any debris that falls into the cylinders. Do not use abrasive wheels or sharp metal scrapers on the heads or block surface; use a plastic scraper and chemical gasket remover, or the head gasket surfaces could develop leaks. 16. Check the engine block and cylinder head mating surfaces for nicks, deep scratches, and other damage. 17. Use a tap of the correct size to chase the threads in the cylinder head bolt holes. Dirt, corrosion, sealant, and damaged threads will affect torque readings. 18. Make sure the new gaskets are installed on the correct cylinder banks (Identify the left and right cylinder head gaskets; the shapes are different and cannot be interchanged). 19. Position the new gasket(s) over the alignment dowels in the engine block. 20. Carefully position the cylinder heads on the engine block without disturbing the gaskets. Install the NEW cylinder head bolts (the cylinder head bolts are torque-to-yield design and they cannot be reused). Following the recommended sequence, tighten the cylinder head bolts in five steps, to the torque and angle of rotation. Note: The method used for the cylinder head bolt tightening procedure is referred to as "torque-angle" or "torque-to-yield" method. Follow the procedure exactly. Tighten the bolts in the first step using a torque wrench, then use a breaker bar and a special torque-angle gauge to tighten the bolts the required angle. If the adapter is not available, mark each bolt with a paint stripe to aid in the torque angle process. 21. The remaining installation steps are the reverse of removal. 22. Install the engine. 23. Change the engine oil and filter and refill the cooling system, then start the engine and check carefully for oil and coolant leaks.

The remainder of installation is the reverse of the removal steps.

Install a new head gasket on the cylinder block, ensuring the correct side faces up.

Loosen the rocker arms and remove the pushrods.

Check for nicks, deep scratches, and other damage.

1. Disconnect the cable from the negative battery terminal. 2. Drain the cooling system. 3. Remove the engine from the vehicle and mount it on an engine stand. 4. Remove the intake manifold. 5. Label and disconnect the electrical connectors from the fuel injectors. 6. Remove the exhaust manifolds. 7. Remove the drivebelt and the drivebelt tensioner. 8. Remove the rocker arms and valve lash adjusters.

Install the intake manifold bolts and tighten them to the specified torque in the correct sequence.

Change the engine oil and filter, refill the cooling system, then start the engine and check carefully for oil and coolant leaks.

Position the new gasket over the dowel pins in the block. Do not use a gasket sealer.

Remove the timing belt tensioner spring stop from the cylinder head.

Smear a little grease in the gap. After cleaning each piston, use a small brush to remove all traces of grease and carbon from the gap, then wipe away the remainder with a clean rag.

Make sure the head is clean before beginning reassembly.

Regardless of whether or not the head was sent to an automotive repair shop for valve servicing, make sure it's clean before beginning reassembly.

Installation of the remaining parts is the reverse of removal.

Examine the valve seats in each of the combustion chambers. If they're pitted, cracked, or burned, the head will require valve service that's beyond the scope of the home mechanic.

Decarbonizing chemicals are caustic and should be used with caution. It is important to follow the instructions on the container.

Pull the valve out of the head, then remove the oil seal from the guide.

Check each valve spring for wear (on the ends) and pits. Measure the free length and compare it to the specifications. Any springs that are shorter than specified have sagged and should not be reused.

Pull up the slack chain and insert the camshaft sprocket, align it with the camshaft, and install the sprocket bolt. Do not tighten the sprocket bolt at this time.

Loosen the cylinder head bolts in 1/4-turn increments until they can be removed by hand, working in a pattern that's the reverse of the tightening sequence.

Remove the engine cooling fan/shroud assembly.

Clean all the parts thoroughly. Make sure all oil passages are open.

A shim can be added under the spring to correct it, but do not shim the springs to the point where the installed height is less than specified.

Use a valve spring compressor to compress the spring, then remove the valve stem locks from the valve stem with needle-nose pliers or a magnet.

Lift the cylinder head off the engine. If it's difficult to remove, carefully pry it off against a casting protrusion, not against gasket surfaces.

Cover the lifter valley with shop rags and use a vacuum cleaner to remove any debris that falls into the cylinders.

The valves and related components will already be in place.