Engine - rattling like a can on start up

[marcus8228]

Hi peeps,

i have recently chanced my arm at an E bay W202 c180 sport


I knew it had issues but hoping to find the cause - so hopefully you guys can help.

Firstly, what should the engine idle at? As i think 500 - 600 rpm seems kinda low, too be fair i haven't checked what my W211 idles at so haven't compared yet.

Also the engine at idle is really rattling like a can, until you get the revs at 1200rpm then runs sweetly.

Drove it today, pulls cleanly, kickdown works like it should, as does the cruise and all electrics - its just this engine rattling noise at idle

Any ideas?

Thanks in advance

Kinda sounds like this but its not a kompressor engine

https://www.youtube.com/watch?v=XuwUU8lC8GQ

[John Jones Jr.]

Remove the drive belt and then start it.

[marcus8228]

https://www.youtube.com/watch?v=JJrliauR_wY

[vaspen]

good lord ! if I were you I would drop the oil pan and check the rods for play sounds like a chewed up bearing
but I could be wrong
I would check first with no pulleys being ran other than crank pulley (the one that has to spin lol)
if no noise then you know its a pulley or accessory that is ran off the belt
if noise persists check engine and tranny mounts as it may just have wore out
in drive break and gas slightly with someone looking to see if the motor picks up a little or a lot
little is norm a lot is bad mount do the same in reverse
600 sounds right in gear 450-650 in gear 7-8 in park or neutral
alldatadiy.com is dam good for 20$ at most I have it for my c230 and it has been wonderfull on my head gasket job / timing chain
that's another thing it could be is a bad timing chain guide or chain could be hitting wall from a bad guide so many possibility so little budget right ? good luck hope I could shed some light on the noise

[vaspen]

oh also while you have the belt off hand spin all pulleys and feel for a binding mainly the water pump (good way to see if it needs replaced )