Valve covers leaking

[Q45Viper]

Ok the inevitable is started to happen. The valve covers are leaking at 137,000. I'm just wondering, I switched to synthetic Mobil 1 about 10k ago after finding this board. That switch was kinda against my private, well trusted mechanics advice. He warned me that if the valve covers were still dry at 127,000 I was asking for trouble by switching. Any opinions? Can I buy time by switching back? Any dangers in delaying the repair, I'm already putting together all the stuff to go under the plenum and do everthing due to bad knock sensors. I just had new O2 sensors put in, is the leaking oil a danger to them?

[Q45tech]

They all usually leak by 120k on conventional oil, same with front and rear main seals.

[HeavyDuty]

I have experienced seepage with a switch to synthetic from conventional, but IMHO, the trade off is worth the hassle.

Besides, I agree that after that amount of mileage, it was inevitable.

[AZhitman]

Lee - The VC gaskets should have leaked prior to that - Mine started at 80K.

Easy job if you're doing the plenum.

[Jeff Williams]

Easy job if you're doing the plenum.

"IF"

It is a pain in the but, if you don't take the plenum off. By the time you get everything off, to get to the covers, you start thinking, "Why don't I dust take the plenum off, it can't be that much more trouble".