new to the MB Diesels... Tell me what to do... - PeachParts Mercedes-Benz Forum

Marshall559 · #1 09-03-2008, 06:10 PM

Hello all,

Bought a 82 300d turbo diesel the other day for 250 bucks. Runs great, has a/c, everything works.

Engine has a slight knock (I have been around diesels all my life) and it isn't a rod knock, and then engine isn't blowing any blue or white smoke. The first thing I tried to do, was crack the injector lines, and see if the noise got any better (indicating a bad injector) but it didn't seem that way... So, my next thought would be a valve adjustment. Can anyone point me to a good book, or a good DIY? Basically, I'm completely new to these MB diesels and want to know some info and where I need to start with this car. Thanks

bgkast · #2 09-03-2008, 06:23 PM

Wow! $250 with working AC?! Lucky!

Try a search of the site (I recommend the google search feature), there is lots of info on here about adjusting the valves. There are special bent wrenches that make the process easier, but they are not required; 2 14mm open end wrenches will work.

Marshall559 · #3 09-03-2008, 07:05 PM

well, I know that I have a 5 cylinder turbo diesel thats a 3.0... now, what chassis/ engine code do I have, and should my car pour black smoke when i'm full throttle (when i'm full throttle on the highway, i see nothing behind me) and how about the engine info?

Oracle12345 · #4 09-03-2008, 07:18 PM

Quote:

Originally Posted by Marshall559

well, I know that I have a 5 cylinder turbo diesel thats a 3.0... now, what chassis/ engine code do I have, and should my car pour black smoke when i'm full throttle (when i'm full throttle on the highway, i see nothing behind me) and how about the engine info?

No not normal, engine info is on the tag in the engine comparment

tobybul · #5 09-03-2008, 07:58 PM

Quote:

Originally Posted by Marshall559

Hello all,

Bought a 82 300d turbo diesel the other day for 250 bucks. Runs great, has a/c, everything works.

Engine has a slight knock (I have been around diesels all my life) and it isn't a rod knock, and then engine isn't blowing any blue or white smoke. The first thing I tried to do, was crack the injector lines, and see if the noise got any better (indicating a bad injector) but it didn't seem that way... So, my next thought would be a valve adjustment. Can anyone point me to a good book, or a good DIY? Basically, I'm completely new to these MB diesels and want to know some info and where I need to start with this car. Thanks

Check this out... http://dieselgiant.com/valveadjustment.htm

Marshall559 · #6 09-03-2008, 08:12 PM

Quote:

Originally Posted by tobybul

Check this out... http://dieselgiant.com/valveadjustment.htm

thankyou so much!.... someone had told me that the valves were not easy to adjust on a mercedes, and now I know they are liars. Very very similar to a cummins engine, with a whole lot less steps.

Chad300tdt · #7 09-03-2008, 08:30 PM

Congratulations on the MB.

Post some pics when you get a chance. You definitely got a good deal for $250.

Try running your VIN# through this site:
http://old.mbclub.ru/mb/vin/?lng=eng

It will give you the options list and your engine and trans numbers.

Have fun with the valve adjustment. A little RTV on the new seal will help it to stay in place while trying to put the valve cover back on.

I also took a pic of everything before I started so I could have a reference for how all the stuff went back together. I've already had the linkage for the bowden cable messed up and was able to verify the correct way with the pic I took before hand.

bgkast · #8 09-03-2008, 08:32 PM

You have a W123 Body with a 617 engine. Try driving it hard for a bit and see if the smoke clears up. My 300SD was owned by a little old lady and smoked like a chimney when I got it, but a few full "throttle" blasts cleared it up.

Chad300tdt · #9 09-03-2008, 08:36 PM

You probably need to do this too:
http://dieselgiant.com/mercedesaldaboostsystemservi.htm

Marshall559 · #10 09-03-2008, 08:49 PM

Quote:

Originally Posted by bgkast

You have a W123 Body with a 617 engine. Try driving it hard for a bit and see if the smoke clears up. My 300SD was owned by a little old lady and smoked like a chimney when I got it, but a few full "throttle" blasts cleared it up.

I don't think you understood, it doesn't smoke at all, from what i've read, they are supposed to smoke at full throttle.

Quote:

Originally Posted by Chad300tdt

You probably need to do this too:
http://dieselgiant.com/mercedesaldaboostsystemservi.htm

thanks a bunch, good info on everything you do!

Marshall559 · #11 09-03-2008, 08:54 PM

I also noticed, that sitting in drive with the a/c on in my MB, it has a pretty good shake... Telling me that one of the cylinders isn't balanced, so, hopefully the valve adjustment takes care of the rough running for me, if not where should I go next? I guess MB is famous for the "shake"... I guess my engine mounts could also be bad...

Chad300tdt · #12 09-03-2008, 08:58 PM

I just recently adjusted the Rack damper bolt and creeped up the idle speed adjustment with success in eliminating the "shake" when in drive at traffic stops.

tobybul · #13 09-03-2008, 09:14 PM

idle should be around 750 rpm. not lower.

Marshall559 · #14 09-03-2008, 09:30 PM

my tach doesn't work.... so i guess i'm out there... lol.. Is the tach signal off of the "w" terminal on the alternator? Also, if I tap the dash, my coolant temp gauge jumps around, my fuel gauge doesn't work at all... all I have the works reliably is oil pressure, and speedo... Can I repair? (main thing is tach for me) or should I find a new one out of the wrecking yard? And what is the rack damper bolt?

Chad300tdt · #15 09-03-2008, 10:07 PM

Quote:

Originally Posted by Marshall559

my tach doesn't work.... so i guess i'm out there... lol.. Is the tach signal off of the "w" terminal on the alternator? Also, if I tap the dash, my coolant temp gauge jumps around, my fuel gauge doesn't work at all... all I have the works reliably is oil pressure, and speedo... Can I repair? (main thing is tach for me) or should I find a new one out of the wrecking yard? And what is the rack damper bolt?

Here's a link about it:
http://articles.mbz.org/engine/diesel/rackbolt/