Cam & Spring Replacement Notes for VR6
Last updated: 7/20/2001
Over the weekend of June 13 and 14, 1998 Tom Doblmaier and Bob Tillman
replaced the stock cams and valve springs in Bob's 1996 GTI VR6 with
Schrick 268s and TT HD springs. These notes are based on the notes
taken during the process, and have been updated with later information
where appropriate. Some photos are included as links in the text.
Disclaimer:
This procedure is oulined below for your information only! While
we've made every attempt to be accurate, we cannot be responsible for
any inaccuracies, nor for any difficulties or damage you encounter.
Parts:
- Schrick cams
- Techtonics Heavy duty valve springs
- New tappets (optional)
- Upper to lower intake manifold gasket
- Side cam cover O ring (small)
- AMV 188 001 02 sealant
- Replacement ECU chip
- Assembly Lube
- Anti-seize
Tools Needed:
- Bentley Manual for vehicle.
- Torque Wrench (adjustable between 15 and 75 ft-lbs)
- Schley 91400 valve spring compressor
- VW tool 3268 (for cam alignment)
- Spark plug wire removal tool (Do yourself a favor and get a "real"
metal one)
- Metric socket set including 27mm socket, "U" joint, and 9-inch
extension
- Standard sized Phillips and flat-blade screwdrivers
- 12-inch Adjustable wrench
- 24mm open end wrench
- 27mm closed end wrench
- Hose clamp or vise grips
- 5 and 6 mm allen keys and socket bits
- Magnetic probe
- Tweezers
- Needle-nose pliers
- A means to hold valves closed while springs are removed:
- Via compressed air:
- Source of compressed air
- Spark plug hole air fitting
- Via the "rope trick" (what we used):
- 8 feet of 1/4-inch-diameter nylon rope
- 5/8-inch-diameter by 7-inch long copper tubing
- Torx driver (to remove ECU cover)
- Tiny screwdriver or chip extractor
"Before" photos:
Procedure:
- Make sure you have your radio code available! Then disconnect
negative terminal of battery and spark plug wires from the plugs.
- Remove engine covers. First, remove the center bolt in the rear
cover. Then remove the rear cover's bolt which holds it to the side
cover (can see this from the back of the motor by the coolant
pump). Then remove the two bolts holding the side cover in place. Now
the rear cover should be free, the side cover should be free and the
silver VW cover can be removed after taking the two bolts which were
under the rearmost cover out. Here's a photo of the
throttle body with the covers removed.
- Remove the PCV hoses going to the throttle body.
- Disconnect the two electrical connectors by the throttle body.
- Disconnect the throttle body coolant
lines. Only one (the one closer to the engine) needs to be
clamped.
- Disconnect the throttle body air boot connection.
- Unhook the throttle cable.
- Remove the plastic cover on top of the radiator. Held on with
three small bolts.
- Remove the two vacuum lines from the front driver's side of the
upper intake manifold (one to fuel regulator, one to brake booster).
- Remove the electrical connector near the vacuum lines on the
driver's side of the manifold.
- If there is no plug in bell housing opening to see flywheel marks,
cover with rag.
- Remove the 5mm bolt holding the dipstick to the manifold. An allen
wrench will work for this.
- Remove the 7 6mm bolts holding the upper intake manifold to the
lower manifold.
- Remove the two rear bolts holding the upper intake manifold to the
engine. Here is a photo of showing where one of the bolts was removed
from the manifold bracket.
- Remove the upper intake manifold. Several photos:
- Stuff rags into the lower intake manifold openings to keep things
from falling in.
- Remove the bracket from the rear center of the valve
cover. (Single bolt).
- Remove the wiring bracket from the rear driver's side of the valve
cover (2 10mm bolts).
- Remove electrical connectors from cam position sensor, auxiliary
coolant pump and coil pack top. Here is a photo with the
Auxiliary coolant pump shown on
the right.
- Remove 4 5mm bolts holding coil pack to side of cylinder
head. Remove coil pack with wires attached.
- Unclip the fuel lines from the passenger's side of the valve cover
(open clips from top, horizontal part of clip).
- Remove 2 10mm nuts from driver's side of valve cover.
- Loosen remaining 10mm bolts on valve cover and remove cover. Cover
with rag to keep stuff from falling in. Some photos:
- Remove 3 10mm bolts holding coolant pump bracket to side cover.
- Remove chain tensioner (27mm bolt)
- Remove 2 6mm at bottom of side cover. Use allen wrench. Have
someone hold coolant pump and hoses out of way. One near the front of
the engine is most difficult.
- Remove 8 5mm bolts holding side cover. The lower most one may not
come out if it's blocked by the coolant hose. Just loosen and remove
with cover.
- Remove 10mm bolt holding wiring harness bracket to front of side
cover.
- Remove side cover - some force here is necessary. Stuff rags into
openings in head and lower timing chain cover where things may fall
down. Here's a photo of the cam
sprockets and upper chain.
- Try to remove dirt from around the spark plug seats using
compressed air or a rag dipped in WD40 on the end of a rod before
removing the plugs, then remove spark plugs.
- Set engine to TDC on cylinder 1: cams have slots which will line
up horizontally with cylinder head top. Timing mark on flywheel (sharp
mark) should line up with bell housing mark. To turn engine over, go
underneath motor and use closed-end 27mm wrench on pulley. Move splash
guard out of way. Moving the bolt clockwise is normal rotation of
motor. (VW tool 3268 is a plastic template which will show when cams
are aligned).
- Tie chain to hood to keep it from falling down into the motor.
- Holding the front cam at its designated holding point using a 24mm
or adjustable wrench, and loosen the sprocket bolt. Repeat for the
rear cam. The bolts are tight!
- Remove the
sprockets. Carefully remove the extra slack from the chain by
tightening the rope holding the chain. Do not allow the chain to fall
into the lower timing belt cover while doing this.
- Remove bearing caps 1 and 7 by loosening them gradually. Then
remove caps 3 and 5 alternately loosening each nut ¼ turn to allow cam
to slowly rise. (We kept track of which nut goes where.) Remove rear
cam.
- Remove cap 4. Then slowly remove caps 2 and 6, alternately
loosening each nut 1/4 turn. Remove the front cam. Here are some
photos:
- Install Schley tool. We needed three washers and a cap bolt to
hold each side end to head. We tried to position horizontal shaft so
it was directly over the nuts holding the ends to the head.
- To use the rope trick (here, and
here), get about 8 feet of
1/4-inch-diameter nylon rope and a 7-inch length of 5/8-inch-diameter
copper tubing. Position the cylinder near BDC and feed the rope
through the tube into the cylinder through the spark plug hole. When
no more will go in (we were able to insert several feet worth of
rope), turn the crankshaft, raising the piston in the cylinder until
resistance is felt. To test if valve is being held in place, press
down on valve spring and valve stem should not move (note: you need to
initially tap the Schley tool lightly to get the valve stem to
separate from the valve spring cap). Note with cams removed, it
is possible to turn motor with 24mm socket wrench on the alternator
pulley. Verify chain rotating smoothly as motor turned.
- Using a magnet, lift the tappet out. Depress the spring slightly
with the Schley tool and tap lightly with a hammer to separate the
valve stem. Verify that the valve stem will not sink into the head by
pushing down on it. It shouldn't move. Here are some photos of
the Schley valve compressor tool installed:
- Depress the spring and using a magnetic pickup, remove the two
valve stem keepers.
- Release the spring and remove the spring cap. Then remove the
springs. Note the comparison between stock springs (on left in photo) and TT HD springs (on
right).
- Replace the springs and spring cap.
- Depress the springs and use tweezers to position the keepers on
the stem. Be very careful not to drop keepers into motor. Slowly
release pressure on the valve spring and watch that the keepers move
into position. Tap Schley tool lightly to verify the keepers are
seated.
- Replace tappet. If tappets are re-used, keep them in the same
positions they were in.
- Do the cylinder's other valve, repeating steps
39 - 44
above. It's easier to remove keepers from side that doesn't have the
lower cam bearing.
- Repeat steps 38 -
45 for remaining 5 cylinders.
- Remove Schley Tool.
- Position piston in cylinder 1 toTDC using a rod inserted in the
cylinder's spark plug hole to get an idea of where this is. Fine tune
the piston position using the timing marks in the bell housing.
- Verify that the intermediate shaft timing mark is lined up! If if
is not, turn the crank one entire revolution and check again. It
should take no more than two additional crank revolutions to get the
intermediate shaft lined up.
- Lubricate tappets, cams, and bearings with assembly lube.
- Position rear cam in place. Install caps 3 and 5 first, slowly
tightening.
- Fit caps 7 and 1 next. Cam may need to be shifted slightly
laterally to get cap 7 to fit. Tighten down slowly. Torque cap bolts
to 15 ft-lbs.
- Position front cam in place. Install cap 6. Install cap 2. This
one is very difficult as the valve must be depressed. We placed a
small wooden block over very end of cam and then used a horizontal
metal breaker bar to push down on the wooden block. Install cap 4
next. Torque cap bolts to 15 ft-lbs.
- Double check cylinder 1 is at TDC and align cam timing
marks. Install sprockets.
- This is key: all slack must be on tensioner side of chain. You
should not be able to hardly move the non-tensioner side of the chain
at all.
- Torque sprocket bolts to 74 ft-lbs.
- Replace small green "O" ring in inside of side cover. Clean cover
surfaces and apply AMV 188 001 02 gasket sealer to surface. Position
side cover.
- Cover timing hole in bell housing with a rag when installing
side cover bolts.
- Loosely install the 5mm bolts in the side cover then fit the
bottom 6mm bolts. Tighten the 6mm bolts first (a drop of oil on each
bolt might help here).
- Tighten the 8 5mm bolts on side cover.
- Install wiring bracket on front of side cover with 10mm bolt.
- Install the coolant pump bracket with 3 10mm bolts. Top most bolt
has to be inserted with needle-nose pliers.
- Install chain tensioner. It should not need to be bled down unless
the piston came out or it was disassembled. The tensioner should screw
in all the way with only hand pressure. If not, then there was slack
remaining on the non-tensioner-side of the chain which should have
been removed in step 55, and your cam timing may be off. Then torque
to 22 ft-lbs.
- Turn the engine over once by hand (two revolutions) and verify the
timing is still the same.
- Remove rags from cylinder head.
- Install valve cover and clip fuel lines back into place on the
side. Note: The new valve cover gasket we had purchased from
the dealer didn't fit, so we re-used the old one with no ill effects.
- Install spark plugs.
- Install coil pack and reconnect electrical connections to coil
pack, cam position sensor and coolant pump.
- Install wiring bracket on driver's side rear of valve cover.
- Install bracket on center rear of valve cover.
- Remove rags from lower intake manifold.
- Install new gasket on upper intake manifold, noting position of
old gasket ("Germany" readable and on left side of manifold if gasket
positioned on lower manifold.)
- Install upper manifold. Install 7 front bolts and 2 rear bolts.
- Install dip stick bolt.
- Install air intake boot on throttle body.
- Install throttle cable, note routing.
- Install PCV hoses.
- Install 2 electrical connectors on throttle body.
- Install coolant lines to throttle body.
- Install 2 vacuum lines to front driver's side of manifold.
- Install electrical connector by front driver's side of manifold.
- Install side engine cover. Position vacuum line in holder on
cover.
- Install silver top engine cover with 2 bolts.
- Install rear engine cover with 2 bolts.
- Install spark plug wires.
- Install plastic cover on top of radiator with 3 bolts.
- Install replacement ECU chip.
- Reconnect battery negative lead (car alarm will sound until door
unlocked).
- Double check all tools and rags removed. Here is
one photo of the reassembled
engine, and here is another.
- Start and drive car. There will be some fairly loud tappet noise
for several seconds as the tappets pump up with oil pressure. Hold at
2000 RPM for a couple of minutes while having someone check for
leaks. Once its found to be leak-free, take a test drive. Avoid hard
acceleration until oil has warmed.
This page is maintained by
Bob Tillman