new mercedes 1991 350SDL owner, looking for advice?

Question

I just got this beast a few weeks ago, and my first drive in it was a 3 hour trip up to my college. Ran like a charm. It has a new engine and even that has over 150k miles on it, but still runs like a charm.

My question is what are the easy steps I can take to ensure a longer life and a smoother ride? I have heard many times that the single most important factor is the oil filter.
How can I check when the oil filter/ air fillter / other filters need to be changed? Or should I just go on a mile ruberic. I do not know much about cars, but I dont have a problem opening the hood to check a few things once in a while. Are there any parts that I should clean every once in a while? Any caps or bolts to check to make sure are tight?

Again, I dont really know where things are in a car except for the major parts, but I am quick to learn. Just want to hear from any other 350sdl owners and their experiences with the car, or anyone else who knows a lot about it and its maintenance. -thanks

anywherebutte, your response is very helpful, it seems like you know a lot about these cars - do you own one? I'm not as savvy as you with cars and I lack the tools/replacement parts etc.

Just tell me what parts I should have in my car as backup - little things, cheap things (but useful things).

Is there a course I can take or place I can go for a basic maintenance overview for taking care of these kinds of cars?

I want to know exactly the steps I need to be taking for changing the oil filter - like you mentioned there were other things you do when you change the oil filter. Anything else Id probably have the mechanic do because he is very good - hes an independent mechanic very familiar with mercedes, hes the one who fixed it up so it could drive in the first place.

But anyway, Id really like to know every step I need to do, perhpas even a link to a video that shows you how to do it (visual learning is bets for me), when changing the oil filters on these cars. Thanks!

Answer 1

Mercedes Diesels need to have their oil changed frequently. Your owner's manual probably calls for 5000 miles, but 2500 would be better. When the oil comes out, even at 2500, it will be as black as coal and as thick as jelly. Oil should be pumped out of the dipstick tube, rather than drained from the pan. If you do use the pan drain, you must replace the copper washer at every change. The oil filter housing has several o-rings that should be changed at every change. I do my own mainenance, because it's hard finding a garage that can be trusted with these little tricks. Mercedes dealer service is far too expensive.

You also should change the fuel filters (there there are two) and air filter about once every six months. You will find that performance will noticeably improve following a filter change.

The transmission is the most delicate and expensive part in your car, if it fails you won't want to fix it. Since I have an oil pump, I make a habit of vacuuming the fluid out of the tranny dipstick tube ever time I change the engine oil. You can get about two quarts out this way, about 1/3 of the fill. I just replace as much fluid as I vacuum out. This is like replacing the tranny fluid once every 7500 miles. At 15000 miles, I drop the pan and replace the transmission filter.

Never put stop leak in a Mercedes cooling system. (If the radiator springs a leak, you're probably looking at replacement.) Flush it out every few years, and fill with either Mercedes brand coolant or a Diesel grade coolant (you can pick these up at truck stops...be sure to get "precharged" coolant). Diesels are subject to cavitation erosion around the liners, so you need a heavy duty 50/50 mix. Never run straight water.

I would recommend going through the engine compartment and replacing all the rubber vacuum connectors. You can buy new connectors for a buck or two apiece at Mercedes dealers, and replacing them all will save you a few mystery problems down the road. While at the Mercedes dealer, get replacement hose for the fuel injector return hoses (small diameter with nylon covering). There is a short, plugged hose on the last injector, replace this and buy a spare to keep in your glovebox. If that plugged hose fails on the road, you'll have a hard time jury rigging a replacement unless you have a spare. The return hoses will cost about $20.

Beyond that, just keep up with things and the car will last another 150K.

One more thing. Despite the age of your car, Mercedes road service will still respond if you have a problem. 1-800-FOR-MERC (I'm assuming you are in the US). They will usually get you started, and may even give you a free tow to the nearest Mercedes dealer.

Answer 2

Change the oil every 3,000 miles along with the filter. Change the fuel filter every other oil change Check the auto trasns fluid If it is not pink change it along with the filter. The air filter is another easy check. All of these things can be done at any garage, no need to go to Mercedes Service. One of the best things is you can get a lot of parts on eBay. Good luck as the motor is just getting broken in...PS Get the Euro head lights. there a easy install and add not only to the looks but make night driving much better. Enjoy

Answer 3

Don't get it hot.After 85 they went to aluminum heads.They crack.
Change that timing chain at 150,000 to 200,000 miles.