GM 90537666 Camshaft, Exhaust Nockenwelle, Gold

Before undertaking the tedious process of removing and inspecting camshafts, you should gather your special tools and get some new bolts for camshaft sprockets. On a 2.0L supercharged model, start by releasing the fuel system pressure; then disconnect the negative battery terminal. Remove the valve cover and set the engine to TDC for cylinder number one, then rotate the crankshaft anti-clockwise until the engine is at 60 degrees before TDC with a diamond-shaped hole on an intake camshaft at 12 o'clock. One thing to remember is never remove camshafts with the engine at TDC number 1 or else valves will collide with pistons and cause damage to both parts. For these engines (2.0L Supercharged & 2.2L), remove upper timing chain guide & secure camshaft sprockets by special tool. To facilitate this process, buy a camshaft locking tool.Remove and put wingnuts on side holding forwardly moved tape-worm wheels.Possibly remove the Camshaft Position Actuators if working on vehicles built during or after 2009; otherwise remove Timing Chain Tensioner if working on vehicles built before 2008.Then disassemble cams while keeping caps marked as to location and direction in which they were removed.All rocker arms must be returned to their original position while all hydraulic lash adjusters should be placed along with corresponding rocker arms.The same procedure should also be used to lift up hydraulic lash adjusters after removing rocker arms from exhaust camshafts in order.Specially made tools hold chain tight & release actuator after loosening actuator bolts while holding wrench onto hexagon of camshaft.Ensure that timing chain remains propped up by locking devices.If removing cams check all engines for proper lubrication between hydraulic lash adjusters, rocker bearings lobes of cams, bearing journals and bearing journal oil clearance.Correct any deficiencies encountered by replacing the parts which are faulty.Prior to reinstallation of rocker arms, ensure they are well oiled together with hydraulic lash adjusters, camshaft must be lubricated and installed correctly.Slide the camshaft sprockets down, tighten new bolts to the required torque and align the slots with sprocket projections before securing the camshaft bearing caps.Adjust the bolts on parts that have been mispositioned during installation.Make sure that you remove Camshaft Locking Tool then install front and rear Camshaft Caps as guided by manufacturers' specifications.Replace upper timing chain guide and also install timing chain tensioner back.Reset&install tensioner & fit upper timing chain guide for it.Once it has gone through at least two complete revolutions check for any kind of resistance involved in making those revolutions.Go ahead to reconnect your battery in order to proceed with engine operation.

To gain access to the camshafts the battery cable needs to be disconnected and the engine set to 60 degree BTDC of cylinder no. 1. First take off valve cover(s) and timing belt, next undo the camshaft sprockets noting which one is which and disposing of the bolts appropriately. This is to mark the position of the camshaft dowels so that it becomes easier to align it correctly when reassembling it. Leverage each of the camshaft cap bolt in a gradual manner beginning with the centre bearing caps, the intent being to lift the camshaft in a direction perpendicular to the cylinder head surface. Again, observe the labeling of the camshaft bearing caps on both the front and rear cylinder heads and ensure you take its picture to help you when reinstalling them. The camshaft and its seal should be unbolted, the Lash Adjusters should be serviced separately by placing each of them in twelve separate small containers to avoid confusion. Check the camshafts and Lash Adjusters for wear; mic each Lash Adjuster OD and look for signs of excessive wear or taper. Check the look of the camshaft lobes and then take measurements of the lobe heights in an effort to find out whether they have differences that are exceptionally high. Inspect bearing journals and cylinder head surfaces for wear; measure the diameter of each journal; check running clearance with Plastigage. Any bearing that has exceeded service limit must be replaced along with the camshaft or the cylinder head as the case may be. For engine installation, the engine is set at 60 degrees before the TDC, the Lash Adjuster bores and the Lash Adjusters being oiled before being repositioned in their correct positions. As a change, new camshaft oil seals must be fitted and the camshaft journals and lobes must be oiled. Place the camshafts back in the originally intended positions so that the pins will be in the least tension as you apply the spring. Apply some anaerobic sealant between the camshaft caps and the cylinder head with an aim of sealing oil leakage later on, then fit the bearing caps, bolts, spacers etc as per the referred positions in the procedure. Tightening of these bearing cap bolts is to be done progressively in quizzed sequence. Remove any excess sealant and go on to fit the sprockets and this timing belt.

Set the engine to TDC (Top Dead Center) for cylinder number one. Rotate the crankshaft counterclockwise to position the engine at 60-degrees before TDC with the diamond-shaped hole on the intake camshaft at 12 o'clock. It's important not to remove the camshafts with the engine at TDC number 1 to prevent damage to the valves and pistons.

Set the engine to TDC (Top Dead Center) for cylinder number one. Rotate the crankshaft counterclockwise to position the engine at 60-degrees before TDC with the diamond-shaped hole on the intake camshaft at 12 o'clock. It's important not to remove the camshafts with the engine at TDC number 1 to prevent damage to the valves and pistons.

The first step is to relieve the fuel system pressure.

Lubricate the rocker arms and lash adjusters, then install them in their original positions.