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hi guys been a while since I have had time to play with the 380slc but the summer is here and I have fixed the water leaks fingers crossed.
When I start it (especially after sitting) there is a real nasty loud rattle as opposed to a tick tick sound....is this likely to be a timing chain issue and is the tensioner adjustable or self adjusting? when it is running there is no sound

I have also added a couple other Germans to the driveway 1 owner 1982 E21 323i BMW and a 320 Baur Cabriolet....not real popular with the wife right now:)
 

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The noise you describe I would bet is your chain tensioner, infamous for bleeding down and allowing a slack chain to bang around. If you do not know the history of your timing chain, it would be wise to at least inspect, and most likely replace it, the guide rails, oilers and tensioner.
 

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westaussie380slc said:
(especially after sitting)

Sounds like the hydraulic tensioner is leaking down. Were it mine I'd not even start it again until diagnosing and repairing if needed.

Read the links in section five of the EGv107.
 

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Clatter on start up

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Sounds like the hydraulic tensioner is leaking down. Were it mine I'd not even start it again until diagnosing and repairing if needed.

Read the links in section five of the EGv107.
Couldn't agree more- you really don't need the chain to come loose- been there, done that on both my cars ( didn't know better) - valves through rocker covers- big $
 

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Interesting. I thought nothing of the clatter I'd heard in my engine on startup. I thought it was just from the valves being dry needing oil. The sound goes away when the car warms up.

I know the 1973 is different than a 380, but not sure of all the ways. (solid lifters?)

I've got the car apart and will be adjusting my valves because the clearance is all out of whack, and I am replacing the timing chain and tensioner (parts for all those jobs already sitting in my garage).

I thought a "tap tap tap" noise would be from the valves. A slack chain would be more likely to drag somewhere due to centripital force. Like this:

I'm not sure how a loose chain would "tap tap tap".

Please educate me! :)
 

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This has also just started on my car, cold start up is fine but subsequent start ups when hot have the rattle of death for ~ 3 seconds.

This has happend the last two times I drove the car. Luckily we now have snow on the ground so the temptation to take the car out has gone and I have all my spare parts ready.

Chain.
Tensioner
Chain rails
Tensionar Rail

I will start the job in the next few weeks.
 

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Fonz,

When you have that "rattle" (which is a very good descriptor) at startup for a few seconds, it's MOST likely to be the hydraulic tensioner. They wear, and bleed off so there is no pressure at startup until system oil pressure comes up. I don't know if 450's have hydraulic tappets, but that would be a clear ticking. And the valve's should be fairly dry. Oil seals prevent lube oil from getting in there and being burned off, or carboning up on the ex. valve stems. At least that's my current state of understanding!
 

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I have changed tensioner, chain, rails, woodruff keys, plastic oil tube holders and 3 leaking hydraulic tappets. These updates silenced chain slapping.

I still have the tap-tap-tap sound on driver side bank - I will change later the rest of the hydraulic tappets and I hope the tap-tap noise will go away.
 
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