PeachParts Mercedes-Benz Forum - View Single Post

earossi · #8 04-04-2008, 05:48 PM

You're right that it has been a long time since this string ran!

But, let's see if I can give some guidance.

First off, if it is just a "tick....tick....tick" sound ONLY on startup of a cold engine and IF the noise quickly quiets down (in less than 20 seconds), my guess is that you have a sticking lifter. What happens to the lifters is that oil pressure pumps them up and as soon as you shut down the engine, the lifters will leak out some of the oil that had been pressurized (normal). There is a single very small hole in the side of each lifter that allows the pressured oil into the lifter. If any varnish has built up in that hole that would restrict the flow of oil to the lifter; or if there is any varnish buildup in the bore of the lifter, then the portion of the lifter that "lifts" will move more slowly then normally. Either of these scenarios will produce the "noisy lifter".

You can isolate it using a stethoscope (inexpensive) that will allow you to put the probe on different components of the engine, and will provide an amplified sound of what is noisey in the immediate area.

So, what is the fix. Well, you could remove the cams and pull all the lifters and have them chemically cleaned. Or, if they have a huge number of miles on them, you may want to choose to buy new ones. Given the age of your car, I assume that it has a great deal of miles on it and does not have enough value left in it to justify a cost of a couple thousand dollars. So, replacing the lifters is a problem. However, if you every have a head job done on the car, the lifters will be accessible and should at least be cleaned.

What I would suggest is trying some super solvents that will attack sludge and varnish.

Kroil Company (mailorder) has a wonderful line of products. You will find them on the internet. At any rate, they make a product called (I believe) Motor Medic.....or Motor Prep....something like that. You'll have to go through their website to find the right chemical. However, it will be advertised as a motor clean up that dissolves sludge.

The good news is if the condition stays the same as you now describe it.....then there is no damage to your engine.....just some annoyance on your part.