VVT Actuator / Timing Gear replacement

Started by onion86, November 25, 2018, 12:31

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onion86

How to: Replace your Variable Valve Timing (VVT) Actuator / Timing Gear
by Onion86 (Stu)

I finally did this to fix my ongoing P1349 saga. The part isn't cheap and it is quite complicated + could result in horribly impacting your timing - so I don't take any responsibility for anyone following this and having issues :)

Tools needed:

  • 10mm Hex socket
  • 12mm Hex socket
  • 14mm Hex socket
  • 14mm Crow Foot Wrench
  • 19mm Hex socket (or Toyota SST) to Crank Engine
  • Adjustable Wrench
  • Torque Wrench


Parts needed:


Instructions:

To Start

  • Remove rear x-brace - 2x 14mm bolts and 2x 14mm nuts
  • Remove plastic engine cover - 2x 10mm nuts and 2x clips
  • Remove charcoal canister for easier access
  • Disconnected your battery


Remove Cam Cover - Refer to below image:

  • Disconnect the 2x PCV pipes
  • Unclip the 4x electrical connectors from coilpacks and remove the 4x 10mm bolts holding the coilpacks in place, remove coilpacks
  • Remove the 1x 10mm bolt and 1x 10mm nut from the electrical rail, move this over to the left (wedge in front of battery) and move the sensor under the nut to one side too
  • Remove 4x spark plugs to make cranking the engine easier
  • Remove the 8x 10mm bolts and 2x 10mm nuts (plus associated loom clips)
  • Disconnect Bank #1 O2 Sensor and put loom / oil dipstick holder (bolt 7) to one side
  • Finally, use a long socket to remove the final 12mm bolt
N.B. the numbers refer to the torque order for re-assembly





  • You should now be able to remove the cam cover, be careful to pick it up over the 2 studs at the back and the timing chain / sprockets
  • The gasket may stay in place on the cylinder head, or stay within the cam cover (where it should go) - replace if required - clean up any sealant and other residue




Get Timing Correct - Also refer: https://www.mr2roc.org/forum/index.php?topic=65009.0

  • Crank the engine with a 19mm socket on the lower crankshaft pulley until the notch in the pulley aligns with position 0 on the part sticking out of the timing cover
  • As an extra check (if you've removed spark plugs) look down cylinder #1 (closest to the chain) and check that the piston it is at Top Dead Centre (TDC) - i.e. as high as it can go





  • Also check that your timing marks align and if you like, you can mark the chain where the marks are on the inlet (VVT) / exhaust camshaft sprockets. Getting these right is very important on re-assembly
  • As an extra check, the camshaft lobes on cylinder #1 should be facing upwards and towards each other (shown in later picture)




Remove Chain Tensioner


Start undoing the Inlet Camshaft

  • Using an adjustable wrench on the hexagon in the centre of the exhaust camshaft (as pictured), use a socket / crows foot to loosen the 14mm bolt on the end of the exhaust cam sprocket whilst holding the cam steady
  • Now do the same on the inlet camshaft and slightly loosen the 14mm bolt holding the VVT actuator





  • Remove the 3x 12mm bolts holding the largest camshaft bearing in place, put to one side
  • Now CAREFULLY remove the 8x 10mm bolts holding the smaller inlet bearings in place. Make sure to do these a little bit at a time (they're quite long) to make sure that your valve springs are let off gradually. For re-assembly, note that they are marked I2, I3, I4, I5 with an arrow that should point towards the timing chain, make sure that the bearings / bolts go back exactly as they came out





  • Now remove all of the bearings / bolts and put to one side:




Remove the Inlet Camshaft

  • I put a piece of string around the timing chain (as above) and then up to my engine cover with a bow so that it didn't drop and I could easily tighten it later..
  • Carefully finish undoing the exhaust sprocket bolt and remove both (DON'T DROP THEM!). Either let the chain drop, or tighten your string
  • Pick up and remove the whole inlet camshaft, removing the chain from the VVT actuator - again tighten the string
  • Now completely remove the 14mm bolt from the end of the inlet camshaft and then remove the VVT actuator itself


Replacing the VVT Actuator / Timing Gear - Refer to below image:

  • The actuator should come in the unlocked position from the factory with the two dots misaligned
  • If it's locked, i.e. both dots aligned, then it should be unlocked prior to installing by applying 20 psi into the actuator, luckily I didn't have to do this
  • Install the new actuator onto the end of the inlet camshaft by putting the pin on the end of the camshaft just clockwise of the pin hole, then twist the actuator anti-clockwise until the pin goes into the correct hole
  • Reinstall the 14mm bolt and torque to 54 Nm / 40 ft-lbf, using a wrench in the centre of the camshaft as you did when you loosened it - make sure to do this on a stable surface, or on a bench
  • Once the actuator is torqued correctly, twist it clockwise into the locked position - it should click as the locking pin engages and then be unable to move in either direction
  • On reinstall, the tooth in line with the long mark should be the one that you align with the chain mark you made earlier





  • New actuator installed to inlet camshaft







Re-installation - Now we just reverse the process

Reinstall cam and chain

  • Put the inlet camshaft back into place, making sure to loop the timing chain back over the new VVT actuator. Place the tooth in line with long mark on the actuator in the link on the chain that you marked prior to uninstall
  • Reinstall the exhaust sprocket by looping the chain over it, with the marked tooth in the marked chain link and place it back onto the end of the exhaust camshaft, making sure that the pin on the camshaft goes back in the hole
  • Reinstall the 14mm bolt into the exhaust cam sprocket and torque to 54 Nm / 40 ft-lbf with socket / crows foot, use adjustable wrench on centre of cam to hold it steady


Reinstall Camshaft Bearing Caps

  • Check that the insides of the bearings are clean, apply a little oil to the insides
  • Reinstall the bearing caps I2, I3, I4, I5 back where they came from and torque the 8x 10mm bolts to 13 Nm / 10 ft-lbf - again remember to do these a little at a time due to the valve springs
  • Reinstall the main bearing cap over the inlet / exhaust cams and torque the 3x 12mm bolts to 23 Nm / 17 ft-lbf
  • Pour a little oil over the camshafts - DON'T GET IT INTO THE CYLINDERS


Reinstall Chain Tensioner - https://www.mr2roc.org/forum/index.php?topic=56959.0

  • Reset your chain tensioner and lock with the clip
  • Reinstall the chain tensioner and torque the 2x 10mm nuts to 9 Nm / 80 in-lbf
  • Unlock the tensioner clip by using a screwdriver down the timing cover:




Get Timing Correct - Refer to earlier section!

  • Make sure that your crank pulley is still in line with 0 (TDC) and your timings marks are in line
  • As an extra check, once you're happy, you can turn the crankshaft pulley through 720o with your 19mm socket and make sure that the marks realign.
N.B. Don't crank the engine unless you have re-installed the Chain Tensioner


Re-install Cam Cover

  • Make sure gasket is new / clean and in the Cam Cover
  • Apply RTV sealant to two places where the Timing Cover / Head meet - as you can see from the before picture on the right, there was originally a nice big dollop here





  • Put the Cam Cover back on
  • Referring to the earlier image, install the 8x 10mm bolts / 1x 12mm bolt / 2x 10mm nuts (and associated loom clips) and torque in the numbered order from 1 - 13 to 11 Nm / 8 ft-lbf without washer or 9 Nm / 80 in-lbf with washer
  • Reinstall Spark Plugs and torque to 25 Nm / 18 ft-lbf
  • Reinstall Coilpack electrical loom, including sensor
  • Reinstall Coilpacks
  • Reinstall 2x PCV pipes


To Finish

  • Reconnect Battery
  • Reinstall Charcoal Canister
  • Reinstall Plastic Engine Cover
  • Reinstall rear x-brace - To Strut : 73 Nm / 54 ft-lbf  |  To Firewall : 75 Nm / 55 ft-lbf

Et Voila!
Sable 55 C-One MR2 C2 Turbo - A/C, Black Heated Leather, TTE Twin Exhaust, Cruise Control

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