Hello. Sorry to bother with chain question again. But is it possible for timing chain to stretch to a point that it will make noise itself with engine running? Is there a way that chain tensioner to max out due to streched chain thus not tensioning chain fully? I do not have tool to check chain stretch.
My car is 92 500sel. 150k ml. Replaced: upper guides, inner guides,(did not change lower guide and tensioner guide but looked with flashlight and they seemed OK), chain tensioner,0w40 mobil 1 syntetic oil.
Problem: sounds like chain makes noise on cold moning start up, oil pressure comes up and I can hear how tensioner tenses chain, oil pressure drops for half a second then goes back up to 3 and then noise is gone
Does it sound like the chain is overstreched? PO drove car with broken guides and seemed like he did not change oil right(oil filter was deformed and cloged). Also when I was changing guides timing marks on camshafts were off by like 1/4 inch on passenger side cylinder bank while chain is tensed(turned engine with starter but didnt start it)
Sounds like I need new timing chain, right?
I am sorry for long post. It just drives me nuts. I work on car myself and learning new things about it everyday. And mechanic says chains last for 300k ml!
Very confused. Please help.
Thank you

__________________
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