Valve adjust .. Now plap-plap-plap-plap

[blackbird225]

I put new turbo valve covers on my 70T this weekend. So I checked the valve adjustment too. (Some mechanic just walking through the drive thru at Taco Bell said, nice car, but the valves are loose, too loose) So I was nervous and decided to check them out. Well, I never saw a Z1 mark , but I saw 2 marks close together and assumed that the one on the left was 1 TDC. A also looked at the dist. and figured out when contact would be made at number 1 cylinder. My fear is that I somehow adjusted one of the other cylinders too loose.
1)What kind of sound might one hear if 1 or two valves are slightly too loose?
and
2) When you are slipping the guide through, do you want it to be so tight that you can hardly pull the blade through. I adjusted it so the blade always had some friction all the way through the crease.

Anyways, the car on one side now makes a very clear plap-plap-plap-plap. Do I need to pull the covers and do it all again?
No loss in power perceived.

Thanks in advance

Michael

[Jdub]

I'd check it again if you are uncertain in any way that you did not line up the marks according to the valve being adjusted.

That said, if you can wiggle the valve pair on a give cylinder then you must have aligned the flywheel correctly for the cylinder at hand.

Also, loose valves don't make me nervous, but tight ones do. All valves tighten over time I believe. Sort of like setting dwell: you preset for a dwell setting at one range anticipating it will wear towards the spec. in short order.

John

EDIT: The Porsche is not the car to determine how a feeler slips between surfaces -- it's just too darn hard to separate the feel from your aching back! I learned on Mercedes straight sixes that sit ever so nicely on top. However, what you are feeling for is a nice drag on the feeler gauge, evenly across. If there is no oil, it will drag heavily, almost scratch. If oiled, it will drag smoothly, but still heavily.

[blackbird225]

I agree about loose valves, but it just didnt make this noise before hand. It almost sounds more like the spark plug isn't seated and air is escaping. I will have to dig into it tomorrow...
I just hope I can reuse my 2 day old valve cover gaskets...

thanks for the reply
michael

[Superman]

I used the same valve cover gaskets (plain $20 set, not the fancy ones) for at least two years, 50k miles and who-knows-how-many valve adjusts. They did not leak. I'm not sure why I changed them.

Plap plap plap is not a valve noise. It might be a head stud noise. Count head stud ("barrel") nuts next time your covers are off. You'll need a small mirror and light. There are 24. Or at least there should be. Put a torque wrench on each one and see if it turns at all, at a setting of, say, 22-24 lb/ft.

[Steve W]

Do I get that right Superman, you can reuse your old valve cover gaskets after doing a valve adjustment?

[blackbird225]

But Superman..
I didn't have the noise prior to the valve adjust. I didnt touch the head nutz.

Can't you use your x-ray vision to diagnose the noise?

Its gotta be somethin I did this time around...

Valves, too little oil, plugs, carb adjust...
I dunno...

[Superman]

Perhaps you failed to tighten something down. No, it sounds like you're concluding it's compression-related. Just under load? If I were worried, I might go back in there and just verify that the valves are properly adjusted. Sounds like you have a grip on the proper feeler gauge "drag." Jdub's description is right on. Also, his suggestion for ensuring you are at TDC for a given cylinder.

It would be irresponsible for me to use my superpowers for purposes other than saving the earth from evil maniacs.

Yes, old valve covers work just fine for me. Your cam housings and valve covers should have straight surfaces to begin with. Gaskets are soft enough and thick enough that they should have no trouble sealing. I believe that many people who think they have leaking valve covers actually have leaking rocker shafts, or return tubes, or something else, and the oil is getting spewed around so vigorously that the valve covers are blamed. According to the spec book, my engine's main fan moves 1500 Liters of air PER SECOND at 6000 rpm. There's a hurricane under there.