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DISCUSSION => Engine + Driveline => Topic started by: melloh on July 11, 2012, 09:11:33 PM

Title: Oil on spark plugs 1 & 2
Post by: melloh on July 11, 2012, 09:11:33 PM

Hello, all.  

As it says, there is oil on spark plugs 1 & 2... a LOT on 1 (the one closest to oil fill cap), and a little on 2.  3 & 4 are dry.

I believe this same thing happened about 4 years ago (~2 years of driving daily) and the mechanic changed the gasket.  Is something else causing the gasket to fail prematurely???      Your advice is appreciated!

(https://lh5.googleusercontent.com/-QZ_sBuO1kmA/T_4xMIezwJI/AAAAAAAABQM/9ZP7NtKUzZk/s685/IMG_20120711_184008.jpg)

Thanks in advance.

Cheers,

Henry

Title: Oil on spark plugs 1 & 2
Post by: Geoff on July 12, 2012, 06:28:00 AM

bout 2 years is all you get..time to re-do the valve cover gasket.   the design I guess is less than perfect, and they all leak after a while.   Doing the job carefully and cleanly results in a 2-3 year life span,  just throw it together and it'll leak before you start it, lol
                                                                G

Title: Oil on spark plugs 1 & 2
Post by: keflaman on July 12, 2012, 02:45:02 PM

And probably better than half of the valve cover bolt hole threads are stripped so it can't be torqued properly.

Title: Oil on spark plugs 1 & 2
Post by: BimwadM42 on July 12, 2012, 07:36:40 PM

I've had them retain a seal for longer than two years, but eventually, the gaskets harden up, and the washers on the bolts (which really provide the clamping force on the cover) lose their elasticity, and the seepage starts.

It's always cylinder #2 on mine.  My VC has been off four times (2x dealer, 2x me), and all my threads are intact.

If the plug tube seepage is the sole issue, and the gasket is relatively new, apply some black RTV sealant (like Permatex Ultra Black) around the seam between the cover and the head.

In your case, that is a lot on #1; replace the gaskets, and just as importantly, the washers.

Title: Oil on spark plugs 1 & 2
Post by: DesktopDave on July 12, 2012, 10:22:00 PM

I'm convinced that this is by design.  Those clever Bavarians selected a material that meters oil to the plugs.  This protects them from rust, provides an anti-seize coating, and cools them during high-RPM performance!
:D

Title: Oil on spark plugs 1 & 2
Post by: Geoff on July 14, 2012, 06:12:59 AM

ach du lieber,  I should have known that:p

Title: Oil on spark plugs 1 & 2
Post by: ///m42 sport on July 24, 2012, 09:44:07 PM

hmm same thing on mine. I didnt know it was valve cover related.  Thanks.