"New" 81 300SD... and having buyers remorse - PeachParts Mercedes-Benz Forum

81mercturbo · #1 07-05-2006, 06:40 PM

I purchased an 81 SD from my brothers neighbor for $4800.00 and I am having serious remorse. The car has 198k miles on it with a new tranny and power steering pump, along with all new window regulators.

The car is leaking really black oil, I can deal with it leaking, for now, but is it normal for diesels to have such black oil? I am afraid to drive it in fear I am going to screw up the engine. The oil level is perfect, pressure is where it should be and temp is right at 80 all the time... but from driving a Honda before, this is not normal for me to see black oil like this.

I have never changed the oil in any car before so I have an appt with my local MB shop for monday to do an oil change and general look over of the car. Should I not drive it in the mean time? Do I run the risk of destroying the engine with black oil?

The car hadn't been driven for 4 or 5 months when I bought it so it just sat. The car pre glows like it should and starts right up without issue. I am new to this whole diesel thing as an adult... 1st car was a 77 240D... I am needing some reassurance here that I did not make a BIG mistake and if I should get out now.

Is there anything I should pay close attention to while driving, other than the temp and oil pressure... any sounds to listen for or anything?

Thanks in advance!!

#2 07-05-2006, 06:56 PM

The "black oil" is normal, it's due to soot collecting in the oil. It turns black very quickly after an oil change, so don't let that worry you. It's also not unusual for these to leak. See if the shop can identify the sources and give you an idea what it would take to fix the leaks. I wouldn't worry about driving it in the mean time. If it's leaking keep an eye on the oil level, you want it to be be about halfway between the two marks on the dipstick after it's been sitting for a while. Wipe of the dipstick, then check the level. Also, take a look at your coolant (antifreeze) level in the tank, it should be about half full.

Your oil pressure should be around 1-2 bars when it's idling hot and pinned at 3 bars whenever you're above about 1000-1500 rpm. Your temperature should be in the 80-90C range (ideally) but they sometimes get up around 100C under load. If it approaches 120C, you want to stop and let it cool off.

There aren't any specific sounds to listen for, unless you hear something that's clearly unusual. These engines are pretty indestructible as long as you don't run out of oil of overheat them severely.

81mercturbo · #3 07-05-2006, 07:02 PM

Thank you... thank you... thank you!!!!

I feel like a weight has been lifted!!!

I was sick to my stomach when I saw that oil... glad it's normal... whew.

Yeah everything else checks out as you stated to check.

I will keep the car and enjoy it... I do love driving it and hope to keep it for a long time.

Thanks for replying so quickly... you made my day!!!

#4 07-05-2006, 07:08 PM

No problem, just bring it to the shop Monday and have everything checked out. Your mileage is only 198K, so your engine should be OK if it has been well maintained. It's good to her the transmission has already been done, they can be an issue at 200K+ miles. Do some searching here, there is LOTs of info on your car.

81mercturbo · #5 07-05-2006, 07:17 PM

I have been doing a lot of research and am getting ready to check out the monovalve. I am the 3rd owner of the car and the original owner was at the PO shop when I took delivery so it was nice to talk to him too.

You guys here are great and very informative... the best forum for MB's that I have seen, by far!!

#6 07-05-2006, 07:54 PM

From the sound of it, you have a perfectly normal "Diesel Automobile" and to top if off you have a "Mercedes". Diesels leak oil..that's a given. You've probably have some seals and/or gaskets leaking. Craig is right on the number with his specifics. To follow up on that i'd definitely take it to an Indy and get it checked out. Let them go over your car. It's a "snap shot" of a "to do list". I'd list them from the most important to the least to repair. Hopefully, you can do most of it yourself.

greasybenz · #7 07-05-2006, 08:04 PM

funny, when my friend was looking at a 81 300SD his dad was worried about the same thing.

But even the 05 VW passat diesel gets black oil. Normal for diesel engines.

#8 07-05-2006, 08:05 PM

Oil color is normal for these engines. There is a brief time that it looks "clean". Thats from when it's in the bottle to when it enters the valve cover.

POS · #9 07-05-2006, 08:11 PM

I've bought and owned many, many cars. The used ones, especially the older used ones, usually commit me to an "acceptance" process.

I love the style of car.
I buy that style of car, and I buy a good one.
I immediately love it.
I immediately start to see all the things wrong with it that particular car.
I start to dislike it (here's "Buyer's Remorse" - sometimes I sell car at this stage).
I fix the big things, and let the smaller ones go.
I start to like the car for what it is - not for what I thought it would be.
I like the car more as I drive it more.
I love that style of car again.
I start searching for another style.

It's a sick, sick cycle. The only way to beat that is to buy new, and I won't do that anymore. I simply run the numbers of a new car, and that idea is blown out real quick.

blueranger · #10 07-05-2006, 09:11 PM

congrats, you will never have to buy another car again...

you finally bought the perfect car. Now all you will have to do is maintain
it... and that is not that expensive...

20 years from now you will be admiring it in your drive way...

my 300 sd is down for a tranny right now and i was just taken with how beauitful it is just sitting in my drive way... I cant wait to have it back up..

81mercturbo · #11 07-06-2006, 12:58 AM

wow... thanks you guys... I really am happy with the car overall, and yes I do believe I have the car that I will keep for a very long time... the "acceptance process" is right on the money!!

Look forward to getting even more info out of you guys in the future!!

rurik · #12 07-06-2006, 10:15 AM

Quote:

Originally Posted by blueranger

Now all you will have to do is maintain
it... and that is not that expensive...

right... not that expensive... in relative terms, compared, say, to maintaining an old Brittish car, perhaps. In the absolute amount of $$ spent -- yeah, it is actually quite expensive. It's a 25 years old car, so naturally a few things may need replacing, and MB parts are not cheap. It's not that big a deal, but you should have your expectations in the right ballpark before you see an estimate from the shop, or there will be some shocking involved. The good news is that if you are a DIY type, this car is good to work on -- lots of good info available on troubleshooting and repairs.