We remove the engine camshafts when repairing the cylinder head, for replacement as a result of wear, as well as when replacing levers, valve stem seals and hydraulic supports for valve levers
We install the car on a lift or a viewing ditch.
We remove the timing belt (article - Checking and replacing the timing belt of the Renault Duster car)
With a head of 8, unscrew the two bolts fastening to the left end of the cylinder head of the bracket for the hoses of the engine cooling system.
We remove the receiver (article - Removing and installing the receiver of the Renault Duster engine)
With a head of 8, unscrew the nine bolts securing the oil separator to the cylinder head cover
Removing the oil separator
Remove the oil separator gasket
Using the 8 head, unscrew the cylinder head cover mounting bolts
Use a flat screwdriver to pry the cylinder head cover by the tides
Removing the camshaft plugs
We take out the intake valve shaft from the cylinder head beds
We also remove the exhaust valve shaft
To assess the condition of the valve arm hydraulic support:
Removing the lever
We take out the hydraulic lifter from the cylinder head socket.
Checking and flushing the hydraulic mounts is discussed below.
When assembling the gas distribution mechanism, the camshaft oil seals must be replaced.
To do this, you need to remove the camshaft pulleys.
We put an 18 spanner wrench on the camshaft pulley attachment nut and insert a powerful screwdriver through the hole in the pulley.
Leaning on the hub of the pulley with a screwdriver blade, press the key with the screwdriver shaft and turn it counterclockwise.
In this case, the pulley with a camshaft should not rotate, and the pulley retaining nut will be unscrewed.
Having unscrewed the nut, remove the pulley from the toe of the camshaft
Remove the oil seal
We also remove the pulley and remove the oil seal from the intake valve shaft of the K4M engine.
On the F4R engine, the intake camshaft pulley is combined with a phase regulator.
To remove the phase regulator, use the Torx T-50 wrench to unscrew the screw that secures the mechanism plug
Removing the cap
The connection is sealed with a rubber ring
With a head of 18, unscrew the phase regulator mounting bolt
You can fix the shaft from turning with a screwdriver inserted through the hole in the pulley, as described when removing the exhaust valve shaft pulley.
Leaning on the hub of the pulley with a screwdriver blade, press the knob with the screwdriver shaft and turn it counterclockwise. After unscrewing the bolt, remove the phase regulator.
Before installation, wipe the mating surfaces of the head and head cover.
Apply special sealant Loctite 518 to the cylinder head mating surface until the surface turns reddish.
We install the cylinder head cover and tighten the bolts of its fastening to the moment in the sequence indicated in the table.
Apply a thin layer of engine oil to the working edges of the new oil seals and put it on the toes of the camshafts.
With a tool head of a suitable size, we press the oil seals into the sockets of the cylinder head.
We check the valve timing using tools (article - timing belt removal).
Before installing the pulleys on the camshafts, it is necessary to degrease the holes and mating surfaces of the pulleys and shafts.
We wrap the nuts (on the F4R engine - the nut and bolt) of the pulleys, but do not tighten them.
We install on the pulleys and tighten the timing belt (article Replacing the timing belt).
Slightly tightening the nuts (on the F4R engine - the nut and bolt) of the camshaft pulleys, turn the crankshaft (removing the shaft fixing device) clockwise two turns and check that the valve timing is correct.
We tighten the nuts (on the F4R engine, the nut and bolt) of the camshaft pulleys.
С 1 по 12
С 14 по 19
21 и 24
- nut of the camshaft toothed pulley: the first stage is 30 Nm; second stage 86 ± 6˚.
- Phase regulator mounting bolt - 100 Nm;
- screw for fastening the phase regulator plug - 25 Nm.
Before installing the oil separator, we clean its channels from deposits.
We clean the mating surfaces from the old gasket and put a new gasket.
The sequence of tightening the oil separator mounting bolts is shown in the figure.
We tighten the oil separator mounting bolts with a tightening torque of 13 - 15 Nm.
Further assembly is carried out in the reverse order.
Checking and flushing the hydraulic valve lifters
Hydraulic clearance compensators in the valve drive mechanism are used to compensate for thermal expansion of the drive elements.
The operation of the hydraulic compensator is based on the principle of incompressibility of engine oil, which constantly fills the internal cavity of the hydraulic compensator during engine operation and moves its plunger when a gap appears in the valve drive, ensuring constant contact of the roller of the pressure lever of the valve drive with the camshaft cam without a gap.
This eliminates the need for valve adjustments during maintenance.
Hydraulic lifters are non-separable compact devices inserted into the sockets of the cylinder head.
Valve knocking when the engine is running can be caused by:
- air ingress into the over-plunger cavities of the hydraulic lifters when the oil level in the crankcase is too low or too high, as well as when the car is parked for a long time on a slope;
- contamination of the precision surfaces of the hydraulic clearance compensators in the valve drive mechanism with sludge from low quality engine oil (or if it is untimely replaced, as well as if the oil filter is damaged);
- wear of hydraulic lifters.
If it is not possible to restore the operation of the hydraulic lifters by pumping or flushing, replace them, since their design is non-separable.
First, make sure that the extraneous noise during engine operation is caused by a malfunction of the hydraulic lifters:
- start the engine. In the event of a malfunction of the hydraulic lifters, extraneous noise in the area of the block head cover appears immediately after starting the engine and changes in accordance with the change in the engine crankshaft speed.
If the noise does not appear immediately after starting the engine or does not change when the crankshaft speed changes, the malfunction is not caused by a malfunction of the hydraulic lifters.
Moreover, if the noise does not change when the crankshaft speed changes, it is likely that the cause of the extraneous noise is not in the engine;
- when the engine is idling, make sure that the noise level does not change when the load changes (for example, when shifting the automatic transmission selector from position N to position D when disengaging the clutch of a car with a manual transmission or when turning on the electrical consumers and the air conditioner).
If the noise level changes, the cause may be the collision of parts due to wear of the liners of the connecting rod and main bearings of the crankshaft, and not a malfunction of the hydraulic lifters;
- warm up the engine to operating temperature.
If the noise has decreased or disappeared, it is possible that the knock of the hydraulic lifters is caused by oil contamination. In this case, it is necessary to flush the hydraulic lifters:
- if the noise has not disappeared, it is likely that air has entered the hydraulic lifters, and it should be removed.
If the oil level in the crankcase is too low, the oil pump traps air together with the oil; If the oil level in the crankcase is too high, the oil is agitated and foamed by the crankshaft counterweights.
When the car is parked for a long time on a slope, oil flows out of the cavities of the hydraulic lifters and oil channels, and the supply of oil to the hydraulic lifters after starting the engine requires some time, during which the cavity of the hydraulic lifter has time to get air.
In all these cases, when oil and air enters the supra-plunger cavity of the hydraulic compensator, the air inside the cavity when the valve is opened will be compressed and the hydraulic compensator will be under pressure, which will lead to a characteristic knock of the valve mechanism with increased clearances.
To remove air from hydraulic lifters, do the following:
check the oil level in the engine crankcase and, if necessary, bring to normal;
- start the engine and warm it up at idle speed for 1 - 3 minutes;
- increase the crankshaft speed to 3000 rpm, then sharply decrease it to idle speed and let the engine idle;
- repeat the cycle and check if the noise of the valve drive mechanism has disappeared.
If the hydraulic lifters are in good working order, the noise disappears after 10 - 30 cycles;
- after the disappearance of the noise, repeat to remove air five more times;
- Let the engine idle for 1-3 minutes and make sure that the noise of the valve drive mechanism has disappeared.
If the noise of the valve drive mechanism does not disappear after bleeding and warming up the engine to operating temperature, identify the faulty hydraulic lifters as follows.
Stop the engine and immediately after stopping, set the piston of the 1st cylinder to the TDC position of the compression stroke, remove the cylinder head cover.
Remove the camshafts.
To test the performance of the engine hydraulic lifters, press on the rocker arm resting on the hydraulic lifter.
If the rocker arm can be moved with little or no effort, the hydraulic lifter is faulty.
Similarly, check the condition of the hydraulic lifters of the remaining cylinders (the order of operation of cylinders 1-3-4-2).
After identifying faulty hydraulic lifters, you must first try to flush them as follows.
Remove the rocker arms.
Remove the faulty hydraulic lifter from the cylinder head socket.
Prepare three identical containers with a capacity of about 2 liters for flushing the hydraulic lifters.
The dimensions of each container must be sufficient so that the hydraulic compensator, lowered to the bottom of the container in an upright position, is completely immersed in the liquid. Fill containers with clean diesel fuel.
Place the hydraulic lifter in the first container and clean the outside of it.
Having immersed the hydraulic compensator in the first container halfway, with the plunger down, gently pressing the wire through the hole, squeeze the valve ball and, keeping the ball squeezed out, move the hydraulic compensator plunger 5-10 times until the plunger movement becomes completely free.
If you cannot achieve easy movement of the plunger, replace the hydraulic lifter.
Remove the hydraulic lifter from the container and, pressing the valve ball, move the plunger until diesel fuel is completely drained from the hydraulic lifter.
Place the hydraulic compensator in the second container and repeat step 5.
Remove the hydraulic lifter from the container and drain the diesel fuel from it as described in step 6.
Place the hydraulic compensator on the bottom of the third container vertically, with the plunger up and squeeze the ball of its valve with a wire.
Keeping the valve ball depressed, move the plunger down and then slowly move up to fill the lifter lift with diesel fuel.
Remove the hydraulic lifter from the container, holding it with the plunger up, press the plunger with slight force and make sure that it remains stationary.
Check the total height of the hydraulic lifter at the same time by comparing it with a new hydraulic lifter.
If during the check it was possible to move the hydraulic lifter plunger, repeat steps 9 and 10 until the cavity of the hydraulic lifter is completely filled with diesel fuel.
If after that the hydraulic lifter does not reach the working condition or its total height is less than the height of the new hydraulic lifter, replace it.
Before assembling the valve drive mechanism, store the filled hydraulic lifters only in a vertical position with the plungers up.
Avoid getting dirt into hydraulic lifters.
Install hydraulic lifters on the engine as soon as possible after refueling to avoid possible loss of diesel fuel.
Install hydraulic lifters and all removed parts in the reverse order of removal.
Start the engine and let it idle for 1-3 minutes. If necessary, bleed the hydraulic lifters as described above.