Timing chain??

[JustinMorrison]

Hi...I know that this subject has been covered over and over, but I didn't find anything specific to my problem with a search, so I'll post the question.
It's pretty simple, about 4 out of 5 cold mornings (well, California cold) when I start my engine (1987 560SEL) to go to work I can hear a ticking noise from the moment I release the key for about 5 or 6 seconds. After that it fades away completely. I left my car overnight at the shop so that my mechanic could hear it (it will only happen the first time, then you have to wait until the next morning to hear it again). He said that it seemed too quiet to be the chain (ticking, not metallic clicking), but too loud to be lifters. The car has 177,000 miles on it, and the previous owner said that the original owner had the chain replaced at 145,000, but I have no way to verify that. I realize that it's impossible to determine what the noise is without hearing it for yourself, but I thought someone might have experienced this before.
thanks,
justin