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Rocker Cover Weep.

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#1 alanwil


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Posted 03 February 2016 - 02:21 PM

Because of the angle of a 240Z engine, the back right hand corner has started to weep between the rocker cover and head where oil tends to sit. Nothing major but annoying. I will replace the gasket but just wondering if I should use a gasket sealant of some sort. Any suggestions? I am a bit wary of using too much pressure when tightening the rocker cover bolts.

#2 Dionysus


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Posted 03 February 2016 - 02:30 PM

As I'm a new owner and not 100% sure I would say depends on the material??


Plastic no, paper yes..

#3 PeterAllen


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Posted 03 February 2016 - 04:21 PM

Hylomar. Used it on Rolls Royce engines, racing motors and road cars for 50 years.

#4 PB260Z


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Posted 03 February 2016 - 06:55 PM

Hylomar. Used it on Rolls Royce engines, racing motors and road cars for 50 years.

Hymolar is good stuff, not real cheap, but IT WORKS !
So yes, I would also use Hymolar

Edited by PB260Z, 03 February 2016 - 06:56 PM.

#5 theremm


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Posted 03 February 2016 - 07:08 PM

I had a leaking rocker cover, replaced the gasket with one from repco, and no leaks anymore :)

#6 Lurch ™

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Posted 03 February 2016 - 07:13 PM

Use a genuine Nissan tappet cover gasket & you won't need to use any sealant ;)

Also, take a straight edge to the tappet cover & make sure it isn't twisted... 

#7 gav240z



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Posted 03 February 2016 - 07:40 PM

I saw a good video of a German mechanic using a copper scraper to clean the engine valve cover gasket surface. Copper is soft so won't damage the alloy head. So should give you a smooth surface when replacing the gasket.

#8 alanwil


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Posted 03 February 2016 - 08:08 PM

 Will get a Repco or Nissan gasket and give it a try. If not then its Hylomar! Thanks for the help.

#9 dat2kman


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Posted 04 February 2016 - 12:51 AM

Old gaskets get heat cycled, squashed, etc, they will weep.
New gasket, and maybe a thin smear of sealant to hold it into place while fitting it!

#10 fluegel


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Posted 09 March 2016 - 09:51 PM

I used to be driven mad by oil leaks from the rear of the rocker cover in several datsuns I tried cork gaskets ,fibre gaskets with silicone or holden gasket cement nothing really worked. I finally sorted the problem here's how first check the mating faces on the cover are really clean and free from old gasket check that the top of the head and rocker cover faces are dead flat, you can do this by loosely bolting on the cover with no gasket and check for gaps with a fine feeler  gauge.Take the cover off if all is well and wipe  any oil from the mating faces then give them a clean with lacquer thinner. Put your fibre gasket in place with no sealant replace the bolts and torque from the center out to about 7 ft-lbs don't over tighten. Redo the tightening sequence to the same torque they will probably turn a bit more do it again until the bolts will tighten no more it is probably a good idea to start the initial tightening at a lower tension like you do with cylinder heads. After a few days driving check the bolts again for correct tightness they will probably turn a bit and maybe do it again some time later. The cover should not leak after this . I don't like gasket sealant because you have to scrape it off if you have to replace the gasket.



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