380SL engine noise - please help

[larryk]

I'm new and really need some help. I will seek a mechanic's point of view locally but would appreciate some expert advice before reaching into my pockets.

I inherited a 1982 380SL that had been sitting for two years. After replacing an electrical relay and the fuel filter, I got the engine running smoothly. It blew alot of blue smoke initially and then ran fine except for a knocking noise in the engine. Due to the circumstances, I proceeded to drive it 1,300 miles from Michigan to Florida with no problems. (I never exceeded 2000 rpm)

It makes a loud knocking noise at the passenger side rear area of the engine that coincides with the engine rpms. I pulled the valve cover and ran the engine for an observation. I did not see anything unusual with the cam, rocker arm or lifters.

It runs fairly well but it is a little difficult to tell becuase the exhaust needs replacing. It may be a little sluggish but starts right up and runs smooth. I was told that the engine would have come apart during the 1,300 mile trip if it was really serious and that it may only be a poor lubrication problem.

Any ideas or advice before I take it to a shop?

[ctaylor738]

Sounds like a failing ball stud- they contain the hydraulic cushioning for the valve train. Try a search on "ball and stud" - lots of information.

The fix is usually to replace all of them, along with the plastic pieces on the cam oiler tubes. You could also try a flush, or to locate and replace the offending one.

You may also have some wear on the rocker arm or the cam lobe.

[larryk]

I have a fair understanding of mechanics but was not aware of the "ball studs" in the mercedes model heads. I believe your advice is right on.

The 380SL only has 82,000 original miles and was my father's. I get sick inside everytime I hear that engine noise. I'll read the other threads carefully to ensure I do the job right using the recomended tools and methods.

Thanks again. I see you have been a great resource to many others as well.

[cwmoser]

Larry, does you 380SL engine have the original single timing chain or has it been converted to dual timing chain?

CW
www.380SL.8k.com

[larryk]

I do not know right off-hand. I did observe and inspect the timing change when looking at the passenger side cylinder head/rocker arms. There was one change on this side.

How would I know? Should there be another on the other cam or are you referring to the chain I saw? I've only had the car a few months and don't have any manuals or literature yet.

Are you suggesting a conversion be done?

[cwmoser]

If your timing chain is a double roller like the one on this URL: www.380SL.8k.com, you are OK. If it is a single timing chain that looks like a bicycle chain or chain saw chain, you better watch real close.

How many miles are on your 380SL?

CW
www.380SL.8k.com

Originally posted by larryk
I do not know right off-hand. I did observe and inspect the timing change when looking at the passenger side cylinder head/rocker arms. There was one change on this side.

How would I know? Should there be another on the other cam or are you referring to the chain I saw? I've only had the car a few months and don't have any manuals or literature yet.

Are you suggesting a conversion be done?

[larryk]

CW

I was able to inspect the timing chain.

Fortunately, the chain is a "double". This, of course, makes me very happy. I didn't want to have that on my mind every time I had it on the road.

It's a 1982 with 82,000 miles - which makes me believe the old single chain was removed and then converted to a double system at some point - extending the wear that would normally occur over that length of time (mileage). Looks like it may have a long life afterall.

Thanks for the advice.

Larry K.

[larryk]

Is there a specific way to remove the plastic pieces on the cam oiler tubes?

I'm not sure if I should just pull on them or what, since the replacement parts have threads on them.

Can someone help me out? Thanks.

[autozen]

Many docoments are tranlated to or originated in english, because it is the only language on the planet with a bazillion adjectives. I can't see how you drove the car that far with a knocking noise. Are you sure it isn't a clattering noise or a tapping noise? If so, I'm inclined to go with Chuck on the valve train. You can drive 1000 miles with a clattering valve train. There are a couple of other possibilities since you don't know the history of repair. The bolts could be loose on the torque convertor or the chain could have been installed by someone who is good at taking things apart and putting them back together but knows nothing about valve timing. The right bank could be too far advanced, and the valves are kissing the pistons. It is possible to have broken rings or excessive wrist pin play, but these are unlikely in that engine.

Peter

[larryk]

Thanks for your observations. However, I am inspecting/replacing the ball studs and need some help with my original question.

Is there a specific way to remove the plastic pieces on the cam oiler tubes?

[autozen]

#1 Yank the tubes off. Remove all the old plastic pieces from them and run fluid through them to be sure there are no clogged holes.

#2 Dig all the broken little plastic pieces out of the cam towers.

#3 Put the new pieces on the tubes and start all the pieces into the holes on the towers. With a small hammer or mallot, tap the plastic pieces down until the sound and feel changes. Remember the object here is to seat the plastic pieces and not to make oval tubes out of round ones.

Good luck,
Peter

[larryk]

Great information. Thanks very much.