Audi Workshop Service and Repair Manuals

Removing and installing camshafts and hydraulic chain tensioner/camshaft adjuster Special tools and workshop equipment required

t  Counterhold tool -3036-

t  Chain tensioner retainer -3366- t  Sealant → Parts catalogue Removing l  Cylinder head installed. –  Remove toothed belt from camshaft sprocket → Chapter.   Caution If a piston is at “TDC” the valves could strike the piston when turning the camshaft. Pistons must therefore not be at “TDC” This could otherwise result in damage to valves and pistons. –  Turn the crankshaft approx. 45° anti-clockwise at the toothed belt sprocket bolt so that all pistons are clear of “TDC” position.

–  Loosen camshaft sprocket using counterhold tool -3036-. –  Detach camshaft sprocket.

Vehicles with variable valve timing: –  Unplug electrical connector -arrow- at inlet camshaft control valve 1 -N205-. All vehicles: –  Remove cylinder head cover → Chapter. –  Remove both oil deflectors.

–  Unplug electrical connector -arrow- at Hall sender -G40-. –  Remove Hall sender → Item, → Item and → Item.

–  Check “TDC” position of camshafts again: l  The two markings on the camshafts must be in line with the two arrows on the bearing caps -arrows-.

If old drive chain is to be reused: –  Clean drive chain and sprockets of camshafts opposite the two arrows on the bearing caps and mark installation position with a coloured dot. l  The distance between the two arrows (and thus between the coloured markings) is 16 rollers on the chain. l  Notch on exhaust camshaft has a slight inward offset with respect to chain roller -1-.   Note Do not mark chain with a centre punch or by making a notch or similar.

Continued for all drive chains: –  Secure hydraulic chain tensioner/camshaft adjuster with chain tensioner retainer -3366-.   Note Over-tightening -3366- can damage the chain tensioner/camshaft adjuster.

–  First remove bearing caps -3- and -5- on inlet and exhaust camshafts. –  Remove double bearing cap. –  Remove the two bearing caps next to the chain sprockets on the inlet and exhaust camshafts. –  Unscrew securing bolts for hydraulic chain tensioner/camshaft adjuster. –  Slacken off bearing caps -2- and -4- of inlet and exhaust camshafts alternately and diagonally, and remove. –  Remove inlet and exhaust camshafts with hydraulic chain tensioner/camshaft adjuster.

Installing l  Pistons must not be at TDC. –  Renew rubber/metal gasket for hydraulic chain tensioner/camshaft adjuster and apply a thin coat of sealant to the -hatched area-; Sealant → Parts catalogue.

–  Position drive chain on camshaft chain sprockets as follows: If old drive chain is to be reused: –  Adjust the colour markings -arrows- so they are aligned.

If new drive chain is being used:   Caution t  The stated number of rollers merely provides assistance for fitting the drive chain onto the camshafts. t  Make sure that the arrows on the bearing caps and the notches on the camshafts align when installing camshafts (with drive chain) in cylinder head → Anchor. l  The distance between notches -A- and -B- on the camshafts must be 16 drive chain rollers. The illustration shows the exact positions of the 1st and 16th rollers on the sprockets. l  Notch -A- is offset slightly towards the inside in relation to chain roller -1-. Continued for all drive chains: –  Insert hydraulic chain tensioner/camshaft adjuster into the drive chain (2nd mechanic required). –  Fit camshafts with drive chain and hydraulic chain tensioner/camshaft adjuster in cylinder head. –  Lubricate running surfaces of camshafts. l  Dowel sleeves for bearing caps and hydraulic chain tensioner/camshaft adjuster must be positioned in cylinder head.   Note When installing bearing caps ensure that the identification mark is readable from the inlet side of cylinder head. –  Secure hydraulic chain tensioner/camshaft adjuster (pay attention to dowel sleeves).

–  Tighten bearing caps -2- and -4- of inlet and exhaust camshafts alternately and in diagonal sequence (pay attention to dowel sleeves). –  Install the two bearing caps next to the chain sprockets on the inlet and exhaust camshafts. –  Remove chain tensioner retainer -3366-.

–  Check correct setting of camshafts: l  The two marks on the camshafts must be opposite the two arrows on the bearing caps -arrows-.   Note If necessary, turn camshaft slightly backwards or forwards so that the two marks coincide.

–  Apply a small quantity of sealant to the -hatched area- of the double bearing cap and the outer bearing cap adjacent to the hydraulic chain tensioner/camshaft adjuster; for sealant refer to → Parts catalogue. –  Install remaining bearing caps (pay attention to dowel sleeves). –  Renew camshaft oil seals → Chapter „Renewing exhaust camshaft oil seal“ or → Chapter „Renewing inlet camshaft oil seal“. –  Torque down remaining bearing caps.

–  Install camshaft sprocket. l  The thinner web of the camshaft sprocket faces outwards -arrows- and the marking for TDC is visible.

–  Tighten securing bolt of camshaft sprocket (use counterhold tool -3036-). –  Install Hall sender → Item, → Item and → Item. –  Install cylinder head cover → Chapter. –  Turn crankshaft approx. 45° clockwise to TDC position via securing bolt for toothed belt sprocket. –  Install toothed belt (adjust valve timing) → Anchor.   Note t  After installing camshafts, wait for approx. 30 minutes before starting engine. Hydraulic valve compensation elements have to settle (otherwise valves will strike pistons). t  After working on the valve gear, turn the engine carefully at least 2 rotations to ensure that none of the valves make contact when the starter is operated. Tightening torques

Component	Nm
Bearing cap to cylinder head	10
Hydraulic chain tensioner/camshaft adjuster to cylinder head	10
Hall sender rotor to camshaft	25
Hall sender housing to cylinder head	10
Camshaft sprocket to camshaft	65