380sl 1985

[WWS]

I have a 380SL as a one owner, since 1985, with about 49,500 miles. The engine has developed a tapping noise ... much like a flutter, not a hard tap and it is consistent at all speeds. Is this the fule injectors? Or one of them? Can these be quieted or does this require a new motor to get the car to run more quietly? It has been consistently maintained very well including oil changes at least twice a year or no more than about 2000 miles since it is not driven on long road trips. This engine's use is probably best thought of as an airplane engine in hours and not miles, I think.
Since I am not mechanically inclined to get into the engine myself, I will certainly welcome any comments.
Thank you.

[page62]

The mechanical fuel injection system uses constant injection, so there's no tapping from the injectors.

Try this: Use a tube of some sort as a listening device. Try to determine the source of the tapping. It could be as simple as an exhaust leak, or as bad as a wiped cam lobe. Watch out for the fan and belts!

I doubt, however, that you're going to need a new engine. But you may need some repair work done. That's life...

BTW: Recently, I had a mysterious rattle similar to what you're experiencing. It turned out that the radiator fan shroud had come loose on one side. It would move backward as I accelerated, hitting the fan and making a tapping noise. It took one screw to fix it!

[airedale]

The 380SL is famous for the right camshaft to wear. Mine was like that when I got it and it had to be replaced. Same sound.

[ctaylor738]

Assuming that the frequency varies with engine speed, I would suggest that it is a "hydralulic lash compensator" aka a ball stud or a HLC. Do a search and you will find a ton of information.

What worked for me to quiet them down on my 560 was to add a quart of Risalone, and run it for about 200 miles getting in a couple of 20+ mile drives where the oil got good and hot. I then did an oil and filter change using Castrol Part Synthetic 10-40.

I still get some light ticking but no tapping.

This worked on a friend's 560 as well.

Obviously, you might need to drain some oil before you add the Risalone.

I have also become sort of missionary about the plastic pieces on the oiler tubes, the 3 chain rails in the heads and the injector seals. If this were my car, I would have all of them replaced.

The seals harden and leak and cause a lumpy idle or high idle. The rails and oiler tube bits get brittle and break and cause serious engine damage. No one knows if this is due to age or mileage and you don't want to be the one to find out. It sounds like you have a nice car and this is cheap insurance to keep it that way. Maybe $30 for parts and 5 hours labor.

My $.02

[airedale]

Here is a link, item # 13, that deals with the right camshaft issue http://www.dianasmercedes.com/BuyersGuide.htm in the 380SL.
The MB dealer told me " we sell a lot more right camshafts " and my mechanic said " it is always the right camshaft that fails. " Somewhere I read the issue was resolved by the time the 560 came about.

[deportes]

CTAYLOR738, you posted the following:
The rails and oiler tube bits get brittle and break and cause serious engine damage. No one knows if this is due to age or mileage and you don't want to be the one to find out. It sounds like you have a nice car and this is cheap insurance to keep it that way. Maybe $30 for parts and 5 hours labor.

Do you know the part number for the plastic ends that may break, on the tubes, 1983 380SL.

[airedale]

These are the folks I used.

Here is a website http://www.**************.com/ and a description.

Later 116 V8 Engine Valvetrain Service Kit
Item # GEG-COML6V

Fits 126 and 107 chassis with the 380 or 420 V8 116 engine.
If you have already read my manual on Preventing Catastrophic V8 Engine Failure here is a kit of the initial parts you need to replace to give you long engine life and peace of mind. If you have not read my manual then I highly recommend you do so. It will explain the problems as well as give you the detailed instructions on how to replace these important parts yourself.

This kit contains the following, 3 new O.E. Mercedes upper plastic chain guides (do not use aftermarket parts here!). one set of plastic oil tube clips, 2 new valve cover gaskets, and eight hard to find copper sealing washers for the valve cover hold down bolts. Replace these parts now or you may be very sorry!

[RickM]

Originally Posted by airedale

The 380SL is famous for the right camshaft to wear. Mine was like that when I got it and it had to be replaced. Same sound.

Agreed, This is what I heard when my CS was being replaced. A search will uncover my experience. Sounded like a sewing machine.

[AF300E]

If you have any mechanical knowledge you can do them yourself.
Just removed the rocker covers, unclip the old (don't bend the brass tubes!), slide the old plastic clips off, slide new ones on and carefully clip the tubes back onto the cam bearings.
Very easy and takes maybe 2 hours?
Hardest thing is to retention the rocker covers without bowing the middles out. You can do it by eye if you know what to look for but if you borrow a torque wrench then even that part is easy.
I'm sure someone will have a picture of a M116 with the rocker covers off.

[Strife]

One comment about the oiler tubes; make certain that they actually click in. The goal is to get them REALLY in without smashing them or bending the tube. The holes in the tube are small and it would be good to make sure that it's absolutely clean inside before replacing.

[t walgamuth]

regarding the cam oilers and such

but i had a lash adjuster stick on my 500sec (84) when i used rotella 15w40 in it. i switched to mobil one 10w30 and the problem vanished.

tom w