|
I believe I had the same problem 3 months ago, 4-6 Cyl, timing went haywire, noise was exactly like yours. I could not diagnose, so I towed it to a friend who has a Porsche Shop here in So. Fla.
Ok, $1800 later it was the Vario Chain Tensioner for 4-6Cyl's, whos Rail Clip broke apart and created that severe knocking. I didn't read everything you have written but it also could be the solonoid attached to the Tensioner that isnt working. I hear thats has been an issue on early models, Just a thought? Also a note on putting the covers back on, be careful as to the amount of Silicon(Loctite 5900, Only two are recommended) as it can jam up the oil return hole next to the bottom Cam and pressure will result in blowing out the Green Cap and leaking oil. We experienced that after and had to redo the the Valve Cover.
Please let us know how you make out of your exhausting deal.
|