2000-2007 Nissan Patrol GU
2001-2007 Nissan Navara D22

There have been several instances where customers have purchased Nissan ZD30 cylinder heads and after fitting the heads there has been a coolant and oil leak at the timing gear case area near the cylinder head.

It is imperative that the correct procedure be followed when fitting these heads as failure to do so can lead to a gap between the timing gear case and cylinder head which leads to a coolant/oil leak.

The correct procedure is as follows:

  1. Fit gasket to the rear of timing gear case.
  2. Install “O” ring to the rear of timing gear case.
  3. Fit head gasket.
  4. Align cylinder head with dowels on the block and sit the head on the block.
  5. Install cylinder head bolts and tension in sequence:
    • 1st: 40-49 Nm
    • 2nd: Loosen cylinder head bolts completely
  6. Install 2 timing gear case bolts and tension to 9.8 Nm. This should close the gap.
  7. Complete tensioning cylinder head in sequence:
    • 3rd: 98-102 Nm
    • 4th: Loosen completely
    • 5th: 40-44 Nm
    • 6th: 90-95º
    • 7th: 90-95º
  8. Tighten all timing gear case bolts to 25-28 Nm.
  9. Check timing gear case to ensure it has pulled in flush with the cylinder head and block.