The oil filter in the 300D W115 is a huge pain, it's almost impossible (note a said "almost") to R&R the canister! Very little clearance, you get covered in dirty oil, etc.

The spring in the bottom stays on the bolt, and I never remove it, just drain all the oil out of the canister. Proper assembly is illustrated on the canister when you wipe the dirt off, either new or replacement. Doesn't explain how the spring got put on top in my brother's.....

If you don't have the plastic filter screen in there, you are circulating completely unfiltered oil with the normal flow through the bypass filter (controlled by a bleed orifice in the housing) isn't going through the filter, either. You can take it to a tech, but I'd not drive any further!

Unless the tech is familiar with these cars, he's gonna have fits to. As I said, you have to get the canister seated and then screw the bolt up, you CANNOT start the bolt first becuase the filter housing tips down and you cannot reach behind it to hold it up, you can only get to the bottom of it. Once you get the bolt up to the canister you can use a wrench. Helps to not have tendonitis (me) or pinched nerves in your neck (my brother)!

Practice makes perfect.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!