Mercury 3R2Z-6A257-DA Camshaft Position Sensor

This process is elaborate and involves the use of special tools and implies the withdrawal of the engine from the vehicle mostly on the timing chain, cassettes and sprockets. In the first step, it is advised to retract the rocker arms and the tools of the valve lash adjusters before working on the cylinder heads, timing chains and the jackshaft chains. Once the engine was dismantled and placed on the engine stand, most of the accessories such as the lower oil pan cover, the oil pump pickup tube and the crankcase reinforcement section had to be removed. Remove the front cover from the engine block, with the reservation that the water pump might be still connected. The engine employs a jackshaft to turn the camshaft timing chains as well as oil pump; the left cylinder bank camshaft is driven by a chain at front while the right one is driven by a chain from the rear of the jackshaft. Unbolt the jackshaft chain tensioner, and guide then unbolt the middle bolt of the sprocket of the jackshaft chain. If it is not already done, then remove the upper bolt of the left-side casket and the lower casket bolt and, in addition to that, take out the cassette along with the chain and then the jackshaft with the camshaft sprockets. If choosing the right camshaft chain, then it is necessary to remove the camshaft sprocket bolt and the upper cassette bolt. The large plug at the rear of the jackshaft must be unplugged and it is necessary to order a new one before reassembly, also unbolt the Torx at the spacer, and the lower cassette bolt, and remove the right-side cassette and chain. When the crankshaft has been turned, make sure the number one piston is at the top of its lift with the crankshaft keyway placed upright: counter clockwise rotation can result in improper engine timing. Place the appropriate camshaft timing chain cassette and bolt on the rear jack shaft sprocket; fit the left camshaft timing chain cassette; tighten all the bolts to the recommended torque. Place the jackshaft chain over the jackshaft sprocket, fit into the crankshaft sprocket and fasten the jackshaft sprocket with the help of the bolt. Mount the jackshaft chain guide and tensioner, while removing the upper timing cover and cleaning the front surface of the engine block and front cover so that a new gasket can be fitted and the front cover bolts tightened. Adjust the camshaft timing for both camshaft sprockets using the above tools and then proceed to reverse the process that was followed in removal. Last but not the least, pour the oil into the crankcase, replace the filter, add coolants to the engine and start the engine in order to check for any signs of leakage.

Engines are intricate, especially during their servicing, and especially timing chains and camshaft servicing or if there is a cylinder head change. It would he wise to do a lot of research before undertaking the repairs and if at any one time you are in doubt, perhaps it is wise to seek professional help. The removal process starts with the removal of the negative battery terminal and the spark plugs with cylinder number one positioned at the top dead centre. Valve covers and timing chain covers must be removed, after which the crankshaft position sensor toothed wheel must also be removed, while taking note of its installed direction. The crankshaft has to be rotated such that it aligns to certain timing marks and various tools have to be used to lock the camshaft from rotating. Timing chain tensioners and chains are then released and pulled out together with the stationary guides and if required the camshaft sprockets can also be interchanged. Different procedures to do with the removal of rocker arms, the inspection of sprocket teeth as well as the examination of the condition of chains are provided for different engine types, and there is a strong recommendation that worn out parts be replaced. Among them are timing chain guides and sprockets that require proper installation and positioning; and tensioners that have to be compressed prior to any lock to keep the engines well functioning. Following these procedures the rocker arms are fitted and with the crankshaft turned an increase in friction is detected showing problems. The final step of the installation process is the reversal of the removal process with due focus being paid on replacement of all Timing marks and other related parts.

Depress and lock the secondary chain tensioner on each bank, using the factory tool (303-1530) inserted in the large hole at the camshaft first bearing cap, or a length of threaded rod and nuts to hold the tensioner down, by pushing from the camshaft bearing cap.

These engines are difficult to work on and require special tools. Procedures involving the timing chains must be read carefully, and disassembly should use the special tools to avoid engine damage.

If a timing chain breaks in an interference engine, there will be damage to the valves and possibly the pistons, necessitating the removal of the cylinder heads.

Position the number one piston several degrees before TDC on the compression stroke.

Inspect the individual sprocket teeth and keyways for wear and damage, check the chain for cracked plates, and examine the wear surface of the chain guides/tensioner arms.

The steps for installing the timing chain tensioners/guides are the same for both sides. Compress the tensioner and lock it in the retracted position before installing.

Disconnect the negative battery cable from the battery.

Remove the timing chain cover and try to avoid turning the crankshaft.

Yes left and right use the same part number.

No, these phasers come with the OEM springs

Yes, the camshaft phaser comes with the bolt

No, this part number will work for both

Each camshaft phaser is sold individually

No, they will work for either side