Knocking when warm

[rasouth]

I have a '78 124 that has a weird problem. The car starts up and idles just fine but when the engine gets warmed up I get a knocking/clacking noise coming from the number 1 exhaust valve area. I changed oil to a heaver weight with no difference. I adjusted the valve clearance and replaced timing belt a few months ago but this noise did not develop until a couple of weeks ago. It does it only at idle and I cannot hear it at higher RPM. Oil pressure is around 38 when started and drops slight to around 25-30 when warmed up.

[BEEK]

have you adjusted your valves lately? i have experenced this before, its kinda wierd. ive had some where the noise would come and go. the only thing i can atribute that is to uneven wear on the shim bucket and the valve head.