Several years ago i removed the engine from my 1985 300TD turbo euro car and rebuilt it, new cyl liners pressed, pistons, bearings, pretty much everything.

Its been driven less than 10,000 miles now and it has developed a rattle that is only present at hot idle, raise the engine off idle speed and the noise goes away. Noise is NOT present at cold idle. Its not a knocking noise, of a injector noise, its erractic slapping type rattle, like the chain knocking around in the engine really.

I removed the lower oil pan, half way expecting to find the oil pump chain tensioner broken or something due to its cheese design, however the oil pump chain and tensioner is ok.

Heres what i found, with a long screw driver i can reach up to the crankshaft sprocket and found that the timing chain itself has a lot of looseness on the drivers side where it goes up to the timing device for the pump. The timing chain will move up and down atleast 1/2 inch. I cannot see either of the plastic guides unless i remove the injection pump timing device, but i found no broken plastic in the oil pan which leads me to believe the guides are ok. Really hoping i dont have to remove the engine and take it back apart again.

The timing chain was new, less than 10,000 miles ago, as well as the tensioner and all guides. My question is, why would the chain be so loose on the drivers side on the crankshaft sprocket, i know the tensioner is on the other side, so this technically is the "loose" side, but i feel this is excessive. I removed the valve cover, chain seems tight on the cam, maybe cause thats the side that the tensioner is on? Not sure really, any thoughts would be appreciated.

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1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg