I got dealer book with oil changes recorded until 120k miles but nothing major like timing chain or other repairs are not listed. I have some receipts from various shops stating brakes,oil changes,ball joint. Ive changed 1 motor mount(it was collapsed).I changed spark plugs and they looked original. I opened distributor cap and cleaned terminals because they also looked original. I dont think its a great idea of grinding terminals since theyre should be gaped I believe. well after cleaning car became a tiny bit smoother. Thanks for cat tip. Ill try to unbolt pre-cats off exhaust manifold and drive around (maybe Ill like the noise and leave them hanging "dragster wanna be" I want to check for vacuum leaks around idle air valve. How do I do that? Is there a place I can connect a vacuum gage to check for specific vacuum number and what will that number be? Thanks for help

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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