Skyline Rb25de Camshaft Cover Gasket Replacement

[Les00x]

Skyline RB25DE Camshaft Cover Gasket Replacement

- Les Lothringer's Approach to Replacing Skyline RB25DE Camshaft Cover Gaskets. May be applicable to other Skyline engines. Similar procedure to servicing Coil Packs / Spark Plugs but stop at Step 15. Photos at end.

- Cost: $100 vs. retail motor workshop charge of ~ $400. Costs are 2010 A$'s Melbourne prices.

- Duration: 4 hours one person.

- Difficulty Level: Easy once you know how, unless something goes wrong.

- Disclaimer: This describes my approach. If you choose to follow it and make a mistake, remember - at all times, it's your fault. If you choose to follow it and get a different outcome, that's because you need to know more than what is described here. No responsibility for errors or omissions. Every car can be different. Torque settings as per Nissan WSM's.

- Reference: Nissan R32 GTR Workshop Manual. [Note: R34 online English WSM does not cover this. If anyone knows of a better R34 WSM source, do let me know].

- WSM Differences: Camshaft Cover Gasket service is similar. Access and removal of the induction gear is different.

- Special Tools: None needed.

- Other Tools: Engine Shroud Hex Screws - 10 mm socket, Hose Clips - Large and Small Pliers, Hose Clamps - Screwdriver, Intake Manifold Collector Bolts - 12 mm 1/4" drive, Camshaft Cover Bolts - 10 mm socket 1/4" drive. Other sockets as necessary. Magnetic Rod to retrieve dropped metal parts.

- Parts: Gaskets Set - 2 gaskets and 2 plugs, around $90, automotive Silicone Sealer, $10. Gasket from AA Gaskets, Melbourne. Nissan also supply. Several suppliers on the Internet but it would be necessary to verify their source, to confirm gasket material quality.

- What Can Go Wrong: Camshaft Cover Gas Recirculation Hose [blowby Hose] front of engine becomes brittle and breaks. Requires Nissan Part #11826-AA511 A$27 and forms part of circuit to vent combustion blowby gases back to the Intake Collector. Standard hose cannot be used. PCV Insulator also deteriorated. Nissan Part # 11812-41B00 A$19. Otherwise hard to go wrong. One may forget to reconnect vacuum hoses / wiring [engine will idle roughly or not start]. Over-tensioning bolts can cause bolts / thread seats to undergo plastic deformation.

Approach:

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A. Set Up

1. Lift bonnet and secure.

2. Remove top of engine Plastic Shroud [10 mm socket].

3. Remove Shock Tower Brace [14 mm socket].

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B. Access to Camshaft Covers - Remove Induction Equipment and Other Fittings [refer photos]

Sequence to Remove Collector Unit

1. Remove Camshaft Cover Gas Recirculation Hose front of engine. Note: Can become brittle and break.Also disconnect Hose to Air Intake Duct [not necessary if only servicing Coil Packs / Spark Plugs].

2. Disconnect two Water Hoses.

2a. Disconnect Hose - opposite side out of view in main photo.

3. Disconnect two Plugs.

4. Loosen Band Clamp to Air Duct.

5. Remove bolt and slide Air Duct towards the left fender.

6. Disconnect Hose.

7. Disconnect the two Hoses - hose with clamp is closest to firewall.

8. Disconnect Hose.

9. Lift plastic clamp off metal retainer.

10. Disconnect two Plugs. Note: One is opposite side, out of view. Disconnect two Hoses, opposite side [out of view].

11. Lift plastic clamp off metal retainer.

12. Disconnect Vapour Recirculation Tube from Collector.

13a. Disconnect Accelerator Cable from Throttle Body.

13b. Remove six Collector to Intake Manifold Bolts. Note: Two are under the Collector. Use a 12 mm 1/4" drive socket [see photo]. Take care not to break plastic hose connectors when removing / installing bolt closest to firewall.

Remove Collector Unit from Engine.

Note: Collector to Intake Manifold has a Metallized Gasket that should come away cleanly and is re-usable. If damaged, gaskets available from Nissan as GSKT-Collector Part # 14033-5L300 ex-Japan [available as at 2010].

Sequence to Remove Coil Pack Coverplate [Ornament as Nissan call it]

14. Remove the four bolts from the Mounting Bracket and lift away from Ornament.

15. Remove the eight bolts from the Ornament.

Remove Ornament from engine.

Sequence to Remove Air Duct and three Retaining Brackets

16. Remove Hose 16a, Loosen Clamp 16b, Remove Flange Bolt 16c - out of view, rear of Duct. Remove Duct from Engine.

17. Remove bolts from the three Brackets left side of engine and bolts on front bracket top of engine.

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Remove Camshaft Covers

18. Remove ten Camshaft Cover Bolts - left side. Remove left Camshaft Cover.

19. Right side the same but first:

20. Remove support bracket right front side of Camshaft Cover - two bolts.

21. Lift up three Coil Pack Cable Retainers using flathead screwdriver - next to Coil Packs.

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C. Prepare Surfaces and Install Gaskets

Note 1: Kit includes two gaskets [non-identical, a left and a right], also two Rubber Plugs, installed at the rear of the engine [see Nissan schematic].

Note 2: Nissan specify using Three Bond 1211 Sealer. A near equivalent is Dow Silicon Engine Gasket Sealer, rated to 220 C.

1. Examine both the Camshaft Covers and Cylinder Head surfaces and remove any material adhering but without scratching the alloy surfaces. Clean the surfaces of the Head and Camshaft Covers. Clean Camshaft Cover Screws.

2. Apply Silicon Sealer to Rubber Plugs and install.

3. Use Silicon Sealer and apply a thin film to the rubber Plugs.

3. Lay the Gasket squarely in the Rocker Cover and apply a thin film to the Gasket.

4. Place the Plug in to the cavity at the rear of the Cylinder Head [see Nissan schematic].

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D. Install Camshaft Covers

1. Install Camshaft Cover Bolts.

2. Torque Camshaft Cover Bolts, working from the middle towards both ends.

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E. Re-Install Induction Equipment

1. Installation is the reverse of removal.

2. After installation, start engine and check for oil leaks.

3. Re-install Engine Shroud.

Note 1: If engine does not start or does not idle smoothly or accelerate correctly, check for unconnected vacuum hoses, unconnected electrical plugs.

Note 2: Some suggest not installing the Coil Pack Cover Plate so that the Ignition Coils run cooler and last longer.

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F. Check for Oil Leaks

1. Start engine, inspect for oil leaks.

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G. Torque Settings ft-lb average [from WSM].

- Intake Manifold Collector Bolts = 20, Camshaft Cover Bolts = 4, Mounting Bracket top of Coil Pack Cover = 4, Coil Pack Cover Hex Socket Bolts = 2, Shock Tower Nuts = 70.

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