How do I change the fuel filter

I had a mechanic check of my Mercedes Benz and found out there is grease around the shift and differential. Because it is a 2000 model, so I don't know is it normal for a old car, or it need repair.

the control arm from the steering column attached to both front wheels

I have a 98 deville it turns over and over if I shake the wire harness it will run but if I shake the wire harness again it will shut off and just turn over when it run it runs just fine need help bad

how do i install a new water pump.

I have change the gas cap with an oem piece,check the fill neck and tube and it looks ok and i have tried the drive cycle test to see if the monitors would be ready so i can go for my inspection sticker and pass the emissions test.How can i go further to diag my PO455 code?

and the brake lights do not come on

wont go over 20 mi per hour, could this be the converter.

it just stoped working

please help me

and if so how do i do it

would like specific instructions

I bought one at Autozone..and thought,I did enough looking to varify which One it was..I was told it is directly beneath the oil filter..And the one there IS different than the one I purchased..Help Please..(new to me)Hard vehicle to figure out..And cant wait for a manuel to come in.Needs smogged,and engine light is On,due to this..verified "ECT".

what color is the wire for the brake lights so i can test to see if there is a wiring issue..

Started after I changed the spark plugs. The engine idles down intermittently and shudders slightly like it is going to shut off.