tiktiktiktiktiktiktik 1968 280se
 

My friend and I met up with the Chicago chapter of the Benz club for a drive through SW Michigan. Our friends were in their '67 250 coupe and we in our '68 280se. Funny thing was there were only two cars at the Hotel, I guess most people bailed for day two.
On the way home, we were driving on the freeway rolling at a good clip for 140 miles. The speed limit is 70 and we were cruising around 70-80.
At the end of our drive, when I slowed down, I noticed there was a ticking noise. I pulled in to a gas station to check the oil level, and I was on the low end of the gauge so I topped it off, thinking that would get rid of the noise. Nope.
I don't have a stethoscope so I was using socket on an extension arm. I could hear the motor pretty well but couldn't isolate the ticking. I haven't put her up on a lift to see the underside of the exhaust manifold but the top looks clean. Once she cools down in a few, I'm going to check the tightness.
Any ideas? Broken spring valve? If the valves seat tighter and wear in some wouldn't the noise become less?

First thing to check is the valve clearance. It is a mechanical lifter engine so if they get loose they will tick.

After that it will get expensive quickly.;)

I've isolated it to the second cylinder or the second from the firewall anyhow. I used a stethoscope and could clearly hear it coming from there. I'm going to try to remove the valve cover tomorrow and hope for the best. :embarasse

my tic on my 107 was a loose manifold bolt, I tried everything to find it and one day just out of frustration tightened manifold bolts and it disapeared, Was not real loose, but just enough I guess

Just needed an adjustment... boy and angry rocker really resonates through the entire car!

Honestly, I thought it was going to be something BAD because I was hauling the mail for over 100 miles with a modern MB and BMW, showing them what the old girl can do on the hwy. I'm sure they were impressed as I pulled off and became depressed with the new noise.

No harm no foul! :)

If you adjust the valves and the noise is still there, it is something to look into. I had this happen once and it turned out to be a bad set of keepers. They eventually sheared off clean and the valve dropped into the cylinder breaking a piston. It didn't really damage the valve though.

I had to replace the piston which turned out OK. Noises always mean something. If you hear a new one, or one that changes from what you are used to hearing, stop the engine or pull over and investigate.

Please be aware that the valve adjusters must turn at or above a certain torque. If the torque is too low the adjuster must be replaced.

Also, modern oil does not contain ZDDP which our older engines need. Many articles have been written about this additive, including The Star magazine from MBCA. Buy some and add it at every oil change or use a diesel specific oil which still has ZDDP. ZDDP breaks down catalytic converters.

Thanks. I adjusted the valves, and tried to stake the the adjuster but it moved on me again. SO I suppose new adjusters is the only solution.

Before spending $$ unscrew that loose rocker adjuster ball stud and smack the top section threads with a hardened ball peen hammer. (ball end)
Just the top part of the threads.
Back up the stud on top of some lead, brass, or aluminum to hammer against.

You'll be surprised how much force it takes to move those fine steel threads to achieve the interference fit.

It may take a few trial tests to get the correct torque fit.

Get a valve spring compressor to make it easy.