Rocker on 4 and 5 redish and rusty looking

[75 911s]

1,2,3 and 6 are normal looking. Rocker 4 and 5 have a rusty appearance.

4 also had one very black and oil covered spark plug.

What do you think?



A little background. A 75 911S 2.7 Car has been sitting for 10 years with bad fuel pump and accumulator. Got it running oil pressure reads fine.

[Amstaff]

Looks like water got inside the valve cover

[75 911s]

Right, my first thought too. So not oil starvation and overheating right? That would look different?

The valve covers had a thick silicone bead with old gasket. I cleaned up both surfaces and put just the new gasket in and tighten the new hardware down in a star pattern snug.

[mreid]

That's the intake side. What does the exhaust side look like on those cylinders?

[SoyRacer]

Originally Posted by mreid

That's the intake side. What does the exhaust side look like on those cylinders?

also look to see what the lobe surfaces on the cams look like. If they're pitted you may me inadvertently milling metal particles off of the cams/rockers and into the engine. Don't fire this engine up any more if you can ovoid it.

[KTL]

#4 has a leaky valve guide

[75 911s]

Here is the Exhaust side

[75 911s]

Best I can get of the lobes I cant see immediate pitting. I'll check when I do the valve job.