buzzing noise when cold?

[bell]

this past week i had to move my 85' targa from my heated garage to my unheated garage. the next day i went to pull it back into the heated, it was around 30 degrees out and when i first started it i hear a slightly lowpitched buzzing noise coming from the rear for 1-2 seconds then it sounded normal.
i haven't gotten into it yet but will be in the next couple of weeks for my valve adj/oil change/gear oil change/plugs and such.
it doesn't make the noise when its warmer (around 50).
i have started to hear some ticking from the valves and the oil level is fine, and there isn't a single oil leak under the car.
any help appreciated.

bell
85'911 targa

[bell]

does anyone have ANY ideas?
it does do it consistantly when it's cold out, but not when it's warm.
could it be either a cold timing chain?
any ideas will help

[don911]

This is a shot in the dark....
Does your car have automatic heat? My automatic heat makes a buzzy kind of sound when cold. If you do have auto-heat, try starting the car with the heat off and see if your noise goes away.

[john walker's workshop]

carrera tensioners tend to do that in cold weather. more of a whirring noise. kind of a non-problem.

[bell]

i did make sure everything was turned off when i diagnosed it.
the tensioners make the most sense, being when i first start it when cold and it makes the noise, then if i shut it off then try again it doesn't make the noise.
i'm going to have a friend start it while i listen to it to determine exactly where it's coming from.
thanks for the help, new noises always make me investigate

[Britwrench]

It may be the vacuum valve just by the oil filler, Porsche redesigned this part and you should check if you have the latest one. Get some-one to start the car and put your hand on the valve, if it's noisy..replace it. There is a bulletin for this somewhere.....