Maintenance Requirement for 1981 300D?
 

I just bought a 1981 300D at an auction with about 186,000 miles on it. It has books with stamps until about 140,000 miles. I got a great car - everything works, no dents, no rust, good original paint and a flawless interior. I've put about a thousand miles on it and the car runs excellent. I've changed all the fluids on it , but I am not sure what else I should do. I sure would appreciate any advise on what else I should check and any additional maintenance I should consider at this point to ensure that it continues to run well for a long time. Also, if anyone knows of a good Mercedes mechanic in the Oklahoma City area, I sure would appreciate a name.

Any advice would be appreciated.

Thanks, Jim

Jim I have an 80 wagon,with a good many miles more than yours.Congradulations It sounds as if you have hit a home run.I would check the valve adjustment. and make sure to exercise the climate control on a regular basis.As far as a recomended dealer.Check the dealer recs on this site and ask the area Mercedes club.Good luck,happy new year.Michael.Carpe Diem.

Congrats on your purchase. The maintenance schedule calls for valve adjustment at 15,000 miles. A lot of people stretch it to 20,000. I would get that done soon, since you don't know when it was done last. These valves get tighter with miles, not looser. Too tight may cause hard starting, or even burned valves. Get the Haynes manual covering the 123 series diesels. Autozone and other places carry it. This book will give you a good general familiarization with the car and maintenance schedule and procedures. Use oil specified for diesels (Shell Rotella, Mobil Delvac, Chevron Delo, etc.) Avoid using cheap oil filters (Like from Autozone or Poop Boys). Give it a dose of diesel fuel treatment. A lot of the guys here use Redline diesel fuel conditioner. Note that there is a diesel forum on this site. Hundreds of diesel owners hang out there. The wealth of knowledge and experience on this site is fantastic. Welcome aboard.

Oops, one other thing I forgot to mention. On the stem of the oil filter cap there are 2 small O-rings. Replace them on at the next oil change. Be careful when working around the oil filter as it is easy to accidentally disconnect some vacuum lines in that area.

Go to your local dealer and see if you can still buy the service book for the car. The one that would of came with the car when new. I was able to get a reproduction owner's manual for my '80 300SD from the dealer. It cost about $15. So maybe the maintanence may be still available.

The cylinder liners in the non turbo five cylinders are more subject to wear than some of the other 123 diesel engines. Do not pay attention to the 5,000 mile oil change interval recommendation. Change it about every 3,000 miles and use an oil especially formulated for diesels. There are several available including Shell Rotella T, Chevron Delo, Mobil Delvac and Mobil Delvac One. These oils contain additives that help deal with soot dispersal, a need specific to diesel engines. There are many that are TESTED and RATED for diesels, but the ones above are ESPECIALLY for diesels.

Enjoy,

FYI

There is a good salvage yard on I-35 between Norman & Moore on the East service road. Oklahoma Foriegn or I-35 Imports. They have a lot of 123s if you ever need any used parts.

Guys, thanks for all the great tips! I really appreciate it. I am anxious to get the valves adjusted and get her out on the road! I did put the Shell Rotella in but now I need to find a new oil filter as I did get the oil filter from Pep Boys!

This forum is great and this is going to be fun. Thanks.