First Time Diesel owner - PeachParts Mercedes-Benz Forum

mamali · #1 04-24-2007, 11:07 PM

Well Dr DKW finally made me buy a diesel!!! It is interesting to say the least driving a diesel. Noisy and slow!!! I ended up getting a 85 300TD. The under body is solid. Motor seems to be okay as well as the transmission. Just about everything else is bad!!!! Vaccume Pump is not working, Car does not turn off. Sunroof, AC do not work. Tachometer does not work. The Po weighed more than 300lbs so the drivers seat is leaning to one side. Other items that need attention as well. Lets see if Dr DKW can actually get me to work on this car!!!

kerry · #2 04-25-2007, 12:19 AM

All TD's have manual sunroofs so you should just be able to turn the latch and open it. 85's are typically pretty peppy compared to early years, so if it seems sluggish, perhaps you've got a blocked switchover valve line or plugged fuel filters.

Jeremy5848 · #3 04-25-2007, 01:18 AM

Quote:

Originally Posted by kerry edwards

All TD's have manual sunroofs ...

Assuming it's really a TD and not a DT...

Mark DiSilvestro · #4 04-25-2007, 07:40 AM

Quote:

Originally Posted by Jeremy5848

Assuming it's really a TD and not a DT...

It's a 1985 W123 300D turbo-diesel sedan.
Except for a bit of rust in the rear wheel-arches, the body appears otherwise to be rust-free, with solid floors & sills. Engine oil-pressure guage, after a good run, idles at about 30.
Usual problems include dead AC, sunroof and odometer.
The most immediate problem, though there appears to be sufficient vacuum from the pump, is that the engine won't shut off with the key.

Happy Motoring, Mark

dannym · #5 04-25-2007, 07:54 AM

Fix your vacuum pump then we'll take it from there:

http://diymbrepair.com/easley/Rebuild_vac_pump.htm

Make sure you build that board. Order a new gasket with the rebuilding kit and use that as a template.

Fix your odometer:
www.odometergears.com

Danny

JimFreeh · #6 04-25-2007, 07:59 AM

Seat spring is easy fix. Find a passenger side seat base and swap it in. Straightforward job, remove seat, split backrest from base, then swap over seat tracks and upholstery. Upholstery snaps into place and can be removed reinstalled with some pressure on the top of the seat squab.
All W123 seat bases interchange, and the W126 with the manual front seat is also the same.

Jim

Mark DiSilvestro · #7 04-25-2007, 08:04 AM

Quote:

Originally Posted by dannym

Fix your vacuum pump then we'll take it from there:

http://diymbrepair.com/easley/Rebuild_vac_pump.htm

Make sure you build that board. Order a new gasket with the rebuilding kit and use that as a template.

Fix your odometer:
www.odometergears.com

Danny

But if the pump provides enough vacuum for the power-brake, would it still be too weak for the IP shut-off?
I was informed by my local indie Mercedes parts supplier that the repair kit for the piston vacuum pump wasn't availible. Didn't try Phil or the dealer yet, now that I have a part number.

Happy Motoring, Mark

Mark DiSilvestro · #8 04-25-2007, 08:13 AM

Quote:

Originally Posted by JimFreeh

Seat spring is easy fix. Find a passenger side seat base and swap it in. Straightforward job, remove seat, split backrest from base, then swap over seat tracks and upholstery. Upholstery snaps into place and can be removed reinstalled with some pressure on the top of the seat squab.
All W123 seat bases interchange, and the W126 with the manual front seat is also the same.

Jim

Actually, I could donate the original drivers seat from my '82 240D. The upholstery and 'horse-hair' is shot but springs are OK. Used by skinny teenagers, not 350 pound woman!

Happy Motoring, Mark

vstech · #9 04-25-2007, 08:18 AM

Quote:

Originally Posted by Mark DiSilvestro

It's a 1985 W123 300D turbo-diesel sedan.
Engine oil-pressure guage, after a good run, idles at about 30.
Usual problems include dead AC, sunroof and odometer.

first off, you have the wrong instrument cluster in your car. your oil pressure should have metric markings. and the needle should have a black button, not a chrome/aluminum one. I bet the car has been monkied with. which of your guages have the black button? those MAY be original. but the chrome ones are not! I bet your tach does not work. the 85 used a different pickup and signal for the tach, so an older tach would not work.
second, are you sure the Vac pump is defunct? have you disconnected everything, including the brake booster, and checked the vacuum with a guage?
tell us more.
John

Mark DiSilvestro · #10 04-25-2007, 08:26 AM

Quote:

Originally Posted by vstech

first off, you have the wrong instrument cluster in your car. your oil pressure should have metric markings. and the needle should have a black button, not a chrome/aluminum one. I bet the car has been monkied with. which of your guages have the black button? those MAY be original. but the chrome ones are not! I bet your tach does not work. the 85 used a different pickup and signal for the tach, so an older tach would not work.
second, are you sure the Vac pump is defunct? have you disconnected everything, including the brake booster, and checked the vacuum with a guage?
tell us more.
John

Yes the tach is also dead. Since the power brakes still seem to function normally, I'm not ready to condemn the vacuum pump. Mike reported the oil-pressure reading after his 35 mile run to pick up the car. He may bring it by sometime this weekend for me to have a look.

Happy Motoring, Mark

mamali · #11 04-25-2007, 10:43 AM

Thanks for all of the replies. I checked the instruments clusters. The Odometer has a silver button as well as the oil pressure , temp gauge etc. The tachometer has a black button. I know at some point the oil gauge was leaking and was replaced may be that was when it was changed. The only thing not working is the tachometer.

Mike

mamali · #12 04-25-2007, 11:47 AM

DOes any one know if the parts for a 1985 300 Wagon and Sedan are inter changable? Mechanical parts in general like the instrument cluster. Thanks

vstech · #13 04-25-2007, 11:59 AM

Should be.
John

rs899 · #14 04-25-2007, 12:00 PM

I wouldn't condemn the vacuum pump yet either. I would suspect the shutoff diaphagm on the back of the IP. With the engine running, gently suck on the brown line coming from the back of the IP. If you get a mouthful of motor oil, that's your problem ( better use a mity-vac...or use it to test vacuum). You will also see oil in many of your vacuum lines downstream. If this is the culprit, do a search here on replacing it carefully, without blowing up your engine.

Rick

dannym · #15 04-25-2007, 12:41 PM

Quote:

Originally Posted by Mark DiSilvestro

But if the pump provides enough vacuum for the power-brake, would it still be too weak for the IP shut-off?
I was informed by my local indie Mercedes parts supplier that the repair kit for the piston vacuum pump wasn't availible. Didn't try Phil or the dealer yet, now that I have a part number.

Happy Motoring, Mark

I was going by what mamali said. he said the pump was broken. He never mentioned if the brakes worked or not. But you raise a good point. I believe it's Mity-Vac time! The vacuum system needs to be tested.
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=92474

Danny