Chevrolet 17120070 Lifter,Valve

To single out a noisy valve lifter at idle, use a hose length next to each valve and listen over the other end of the hose. Alternatively, remove the rocker arm cover and put fingers on valve spring retainers one by one while the engine is idling. If a faulty lash adjuster is present, it may be felt as the valve seats shock that often indicates trapped dirt in it. To do so first disconnect and ensure that there are no lockout features engaged if you have a Delco Loc II audio system and this is done by disconnection of the negative battery terminal. Remove rocker arm covers; loosen rocker arm nut and push rocker arm away from push rod as shown below: The next step is to take off the pushrod making sure to remove it carefully using a magnetic pick up tool or scribe in case removing any lash adjuster. For stuck lash adjusters, avoid damaging them from outside using a specialized hydraulic lash adjuster removal tool. In case you are going to remove several of them, keep them in a labeled container for reinstallation into their original positions. Cleaning the lash adjusters with solvent check for wear, scuffing, or uneven wear particularly on lash adjuster walls, pushrod seats, and foot. The base should slightly bulge outwards while concave ones indicate that both camshaft and lash adjusters require replacement. Examine lash adjuster bores in the engine block if lash adjuster walls are damaged or worn. Outer rollers should be free-rolling so they need to be checked (for roller lash adjusters). When replacing new lash adjusters, always get yourself another camshaft since used ones cannot be reused unless they are fixed back at their previous places together with the initial camshaft. Always ensure molybase grease or engine assembly lube has been applied on lash adjusters before installation then can proceed with other steps in reverse order.

This is rather delicate work that must be done with special equipment and, hence, it is advisable to wade through the entire process and gather all the tools that are going to be used in the process. Start by loosening the cable connection to the negative terminal of the battery then follow by the removal of the valve cover. Rotate the engine to TDC for cylinder number one, anti-clockwise until the crankshaft reaches sixty degrees before TDC, do not remove the camshafts at TDC number one because this will damage the valves and pistons. Subsequently, take off the upper timing chain guide and in its place, fix a locking tool for the camshaft sprockets to stay locked. When c.f. loose the camshaft sprocket bolts then you can slide the camshaft sprockets forward but before that make sure that you tighten the wingnuts. Numbers are inscribed on the main part of the camshaft cap with the numeration which will show the position; each bearing cap bolt should be diluted gradually and equally so as to let the camshaft float up from the cylinder head. Group all component of each camshaft respectively to ensure that they are not misplaced. The next step is to take out the rocker arms and set aside in order that they may be refitted, together with the hydraulic lash adjusters, which must be withdrawn from the holes in the cylinder head in which they are carried. Remove and mark the position of the exhaust bearing caps then do the same thing to the rocker arms and hydraulic lash adjuster. See also that each of the hydraulic lash adjusters is worn out or not and then check their diameters to find out if they have undergone excessive wearing. Check the conditions of the rocker arms and camshaft lobes; measure height of the lobe and compare it for high inconsistency. Examine under the bearings and valley deck for wear and measure the diameter of camshaft bearing journals, and cylinder head bearing surfaces. To ensure that the bearing journals' oil clearance is accurate, clean all the bearing surfaces followed by the installation of the camshafts and the bearing journals with Plastigage across each journal, to find the width of the flattened Plastigage. If any bearing is worn out to the extent of the service limit, then it is advisable to replace the camshaft and or cylinder head. To check camshaft endplay clean the bearing surfaces fit the camshafts and bearing caps in position and use dial indicator to measure the end play of the cam shaft. In the event that the endplay is beyond the service limit, a new camshaft thrust cap should be fitted. For the installation, it is required to lubricate the rocker arms and hydraulic lash adjusters and place them in their appropriate positions and lubricate camshafts before the establishment of the same. Place the camshaft bearing caps in place, use a step like sequence to tighten the bolts, slide the camshaft sprockets and timing chain forward towards the camshafts so that the slots in the timing chain fit into the projections on the sprockets. New bolts are required to be put on and the camshaft sprockets tightened, after which the camshaft locking tool has to be withdrawn and the front and rear caps of the camshaft are to be installed. Bolt on the upper timing chain guide and turn the engine with your hands to feel some level of resistance. Finally, reconnect the battery.

For both the intake and exhaust parts, you should loosen the camshaft housing-to-cylinder head bolts in 1/4-turn increments, following the tightening sequence in reverse.

Common causes of noisy valve lifters include dirt trapped inside the lifter and issues related to oil flow, viscosity, or pressure.

Each camshaft cap must be marked for location and direction.

Mark each rocker arm to ensure they are returned to their original positions, then lift them from the engine.

Clean the lifters thoroughly and check for wear; if the lifter walls are damaged, inspect the lifter bores as well. Ensure the rollers turn freely without excessive play. Used roller lifters cannot be reinstalled with a new camshaft, so always use new lifters with a new camshaft.

Store the lifters in a labeled box to ensure they are reinstalled in their original locations.

The remaining installation steps follow the reverse order of removal. After everything is reassembled, run the engine to check for oil leaks.

When reinstalling, ensure lifters are placed back in their original bores, soak new lifters in oil, and coat all with moly-base grease or engine assembly lube before installing the pushrods and rocker arms.

Various methods can be used to extract the lifters from the bores, depending on the specific situation and available tools.

After installing the camshaft, you should install the thrust plate and tighten the bolts. Reinstall the oil pump drive.

If any camshaft journal diameter falls below the specified value, it is necessary to replace the camshaft.

To remove the lifters, first take off the intake manifold and valve cover, then lift each push rod out of the cylinder block. A special tool can be used to pull the lifters out, or a sharp scribe can be employed to force them upwards, avoiding the use of pliers on the lifter body.

Next, take out the bolts holding the roller lifter guide to the block and remove the two guides, marking them for their original sides.

Lubricate the lifters with clean engine oil and install them in the retainers, ensuring proper alignment. Tighten the lifter retainer bolts to the specified torque.

The final steps of installation are the reverse of the removal process.

After removing the lifters, you should clean them and inspect them for scuffing, score marks, and uneven wear. Additionally, check the rollers for wear and damage. Replace the lifters if necessary.

A common cause of noise is dirt trapped between the plunger and lifter body.

Begin by removing the cam carrier and the lifters from the cam carrier housing, keeping the lifters in order for reinstallation.

Unplug the oil pressure sending unit wire and unbolt the engine lifting bracket.

A noisy valve lifter can be isolated when the engine is idling by using a mechanic's stethoscope or a length of hose near each valve while listening at the other end.

The procedure is for removing lifters from an engine.

A noisy valve lifter can be isolated while the engine is idling by using a mechanic's stethoscope or a length of hose near each valve location, listening at the other end. Alternatively, you can remove the valve cover and touch each valve spring retainer one at a time to feel for shock if a lifter is defective.