Very soon will be changing chain and guides again. At least inspecting them. Noise is coming from driver's side top, more toward the middle of the engine. It sounds like something is grinding against something. My thought is that one of the guides broke due to low oil pressure. I did not change driver's side lower guide. Now I will. Not the one in crank case. Too much work. And driver side and passenger side camshafts do not align by like 1/8 of an inch. So I think chain is too stretched. Now I'm looking for chain crimper.
I read somewhere that guide in crankcase never fails due to it's size and it's always in oil. What do you guys think?

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1999 ML430 Silver 135k ml
Smoked LED taillights, Alpine in-dash DVD player, 12" sub, Pioneer components, 2 amps, 4200k HIDs, ML55 headlights, 20" rims, mirror LED blinkers

SOLD. 1996 E320 145k ml. Burgundy

SOLD but miss it everyday 1992 500sel Black
Chime buzzer mod,Alpine CD/MP3 player with stock amp,Euro headlights,S600 grill,20" rims, BEST CAR EVER!

SOLD. 1990 300E White
187k ml,smoked tails,Euro headlights,17rims,Intake,12" sub in first aid kit,alarm/autostart,buzzer mod