I just wanted to post this for anyone who might have a similar issue. I just bought my third Mercedes Diesel. I had 2 before, both of which were destroyed by my new driver ex-girlfriend.

Luckily this car is now mine and I have had it blessed and some voodoo magic to protect it.

I took the car on a nice 300 mile trip to moms house the weekend I bought it.. just to give it a good test run

Everything went fine. This week had it inspected and passed easily. Then I went to start it one cold morning and it wouldn't start. Only the engine would turn. Of course I needed to move it since the car was sitting in front of my old BMW I had just sold and was being picked up in an hour. After a few curses..I pulled out my tools.

It was cold out, and I had replaced the secondary fuel filter before seeing it was dirty the weekend I got it so I took out my spare secondary fuel filter and changed it again. This time I noticed no matter how much I pushed the gas pedal (is it a diesel pedal in this case?) while starting that secondary filter was only getting a tiny bit of gas.

So I pulled out my primary fuel filter I had bought in preperation for this moment, and switched it out with my 22mm wrench (bought specifically for this car from my other two). I then unscrewed the hand pump for bleeding the fuel system. After pumping out the air, then realizing I hadn't closed the pump the car started right up. The old fuel filter was filled with debris, so I think I found the source of the problem. I'd like to clean out my tank to prevent this from happening again, however its bloody freezing out (30 miles from Toronto in WNY) and I'd rather not have to pay $200 for a shop to do it.

So I will keep a couple secondary filters, and a primary as spares in case it happens again. (not to mention a diesel spoiled pair of gloves)

Figured I'd share this in case anyone else has any issues starting. It wasn't the glow plugs or the cold morning. Just a dirty clogged filter.

I am a happy owner of a new (old) 81 300d Just needs some love in a few places but the interior is nearly flawless. I really love these cars

-James