My car 1990 190E 2.6 with 166K milage, makes a tic tic type noise while starting in the morning for 1st few seconds and the sound goes away when oil pressure rise. Typical timing chain sound, right?

So after searching several post, I decided to replace the timing chain tensioner as many had suggested that the chain in M103 motor does not need to be replaced. Upon inspection, the old tensioner did not extend much, may be 3-4 mm (13mm= replace chain, right?). The old spring was 2-3 mm shorter then the new one. Anyhow, replaced the timming chain tensioner.

The sound still existed. I read somewhere in the forum that the same type of noise can be created by a loose valve lifter (I don't know what it is)

Q1. How do I differentiate if the noise is due to valve lifter or loose timing chain?

Q2. If it is due to valve lifter how easy it is to fix, can I do it by myself? what materials do I need?

Q3. If it is due to timing chain, how easy to do that? I saw some DIY pics and seems not too tuff. What stuff do I need buy like, oil seal, .....etc

Your expert opinion plz.

Listen to it with a stethoscope to see if you can determine where the noise is coming from. Sometimes you can get an idea, and sometimes you can't, but it's always worth a try.

Next you can pull the valve cover and check the lifters. They will all be a bit loose with the engine stopped, but you want to see if any are much looser than the others. You will have to turn the engine over a few times, as you can only see what's going on if the valve is closed.

If you think any are loose, you can remove the lifters, carefully keeping them sorted so that you do not put them back in the wrong place. Immerse each lifter in oil and pump on the piston with a tool. They should become very stiff after just a few strokes, and if not, all of them should be replaced.

I don't know if you have roller lifters on that engine, but if not, it is imperative to never run a used lifter on a different cam lobe than before. If you renew the lifters, do a camshaft break-in when you first start the engine.

I don't think I have ever heard a timing chain make noise in a 103 motor. The tentioner is a ratchet type so it doesn't get loose with lack of oil pressure.

As was stated listen to the motor when cold with a stethescope or a long think screw driver placed to ones ear. It will amplify the noise. If you are lucky you will be able to narrow the sound down to one rocker assembly. I would the replace all the lifters in that assembly at least.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Try running some BG-44 in the oil as per instruction to clean out the varnish/crud that may be causing a lifter to leak down over night.

We had experience with sludge build-up on the oil pump intake screen in our Grand Marquis. The oil pan does not just come off, a cross-member has to be removed, or the engine removed, or you drill a hole in the pan and then weld it shut... but I digress.

So, we tried reaching through the oil drain hole to knock off as much as possible, and then an oil change with synthetic oil. We figured that since it was motor oil it could not hurt, and being a higher-detergent synthetic, it might help to clean out a lot of the gunk.

There were 2 or 3 episodes of low oil pressure warning lights. Each time we stopped, waited a moment, and re-started to find it was fine.

Once the valve train got really clackity and clattery due to a temporary clot in the system. This also cleared up after a stop and restart.

6,000 miles since, 217,000+ on the odometer, and it's doing fine. We are back to using dino oil since it consumes about a quart per 1000 mile due to worn valve seals.

To summarize, if you think that varnish is blocking a lifter, you could try a change with synthetic so see if it will dissolve.

Others will chime in here...