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

Justin:

We 2nd or 3rd owners of cars we can't verify prior chain replacement on are all in the same boat. I got mine at 149K and now it has 170 K.

I think we are both on borrowed time.

Consider it a necessary expense to do the tming chain by an experienced independent. Even if its not necessary.

Justin,

Hard to tell w/o hearing the clicking, but your description certainly sounds like it could be a bad lifter --- clicks until enough oil pressure has built up and the noise goes away.

You might want to get a second opinion from another mechanic. I

The chain itself is not neccesarily the main issue for concern, but the upper chain guide rails. They are made of plastic and become brittle over time. Since you don't know the oil change history, wouldn't be a bad idea to pull the valve covers and inspect them.

I dont have a V8 engine, But in 190E's, it has always been timing chain tensioners. It relaxes over night 'cools down' and when you cold start the car in the morning, it will take up to 7 seconds for it to go back to its normal tension. Meanwhile your chain is flopping around "the ratt-ratt-ratt noise" and one day it could break leaving you with a dead engine. I would replace the chain and the timing chain as well as the rails!

[mplafleur]

I'm inclined to believe it is a lifter. The 190's have a spring held ratchet as a tensioner, not the oil pressure held tensioner. Once the chain stretches enough for the spring to push out the tensioner out another click, it will ratchet out and stay. It cannot go back in. I fail to see how the spring tensioner can cause the noise mentioned while oil pressure is obtained.

BTW. Mine does the same. How can I determine which lifter is faulty?????