need help. 1982 300d turbodiesal
 

I love my car but the only gauge that works is the gas gauge. The brake light is always on. Air conditioner doesn't work. Car doesn't turn off when I pull out the key so I have to open the hood and manually turn it off. Trunk opens once in every one thousand tries. Sometimes locks are funny. How do I fix it?

When's the last time you changed the blinker fluid?

That's alot of problems, most common for these cars. She can be saved.

You dont have a "gas" gauge. Which brake light? the indicator light at the dash? Have you checked the A/C system? The vacuum system shuts the car off, start there for issues with the shut off. Ditto with trunk and locks.

Where????
 

Where are you located? If you are within 30 miles of me, then we should get together. I've learned a lot from this forum and will share it with you.

Owner of 1982 300d turbodiesal
 

I wish I lived near you. I live in California. Yes, you are all right it isn't a gas gauge. My diesel gauge is the only one that works. The light is the light that is illuminated when you normally go to drive but leave the e-brake on. I have not changed the blinker fluid since I got it about a year ago from my dad. How would I go about repairing the vacuum system?

The search tool is your new closest friend.

Use it to find threads relating to your problems, you will find alot of useful information.

I disabled my locking system, that ended my vacuum problems.

I've also had a few fuses pop and kill my instrument cluster. Could be the ground as well.

You need to change that blinker fluid as soon as possible. It is the number 1 killer for diesel engines.

Well, in terms of gauges...theres a great thread on removing the gauge pod...Id take a look behind there for broken or loose wires. Not to insult you but also check fuses...sometimes those euro fuses look good but have a hairline crack in them. The Gauges are relatively simple devices...if theyre bad, repairing or replacing shouldnt be a mind-blowing task.

Alright, now we have the IN-Famous engine shutoff problem.

The Merc Diesels relied heavily on vacuum for functions...including things like shutting the car off, locking the doors, and brakes...this is where you go to Sears and get yourself a Mity Vac if you plan on keeping this car a while! (trust me, its a great investment)! The vacuum pump sounds like its working because I assume you can stop fairly easy so lets isolate the shutoff valve!

Diesels need their fuel shutoff becasue they dont rely on a spark for their life...therfore, Merc used their vaccuum pump to literally "suck" the fuel valve shut. This is a brown vacuum line on MY car but it may be the same on yours...if you wanna try this...disconnect one side of the line and literally "suck" the valve closed with your mity vac or your mouth. If it doesnt hold a vacuum...bad valve ($35 on this website)...if it does hold vacuum...try to isolate the circuit that may be leaking.

Look for cracks in lines, broken lines, worn out rubber boots, or missing lines all together!

Do a search for threads here, visit the DIY section or visit Diesel Giant.com for a great list of DIY tutorials with color pics for your car.

I BELIEVE you have the vacuum pod on your car...its by the fuel tank...if this is leaking it wont hold the vacuum needed to unlock or lock all your doors...also a vacuum leak in the system would drain the vacuum from this. Dont forget to make sure your locks are clean too (also, a great thread for the cleaning of these locks).

Search around...we all have seen these problems!

hey we are in the same boat with my 1984 300D

brake idiot light wont go off

only gauge is the fuel gauge and ha i'm rockin better than you my speedo will occasionly work and i do have a slightly cool AC not worth a damn in OKlahoma. and my trunk opens smoothly.

and today my car started the no turning off thing

so if i come across any information or solutions ill let you know, I know how you feel but just keep in mind that "this too can be fixed"

ive considered ripping out the whole gauge panel and replacing with good ol Auto Meter gauges

thanks a lot. All your comments have been really helpful. After I finish finals I intend to fix everything. Also do they have online manuals for mercedes or do you have to pay for them?

I know what you mean. I have many things on my to-do list after finals.

#1. Step by step blinker fluid change. http://www.geocities.com/changeyourblinkerfluid/blinkerfluid1.html

Well, $20 is not much money, I think, for the cd-roms from mbusa.com

Which brake light are you referring to? The red one, parking brake on, and low fluid level, or the orange one, low brake pad wear indicator?
A/C, normal.
Engine not shutting off is a vacuum leak somewhere, or failed shut off valve.
Trunk opening, depends on the lock position, does it open any time with the drivers door unlocked? Spray some lubricant in the lock, and work the key back and forth.

how does one seek and find said vacuum leak

The light I am referring to is the one that alerts you when you are driving with your emergency brake on.

That is the red one. First thing to check is brake fluid level in the M/C.

A tool called a Mity-Vac, or something similar. Hook that up to various vac lines, see if it holds vacuum.
There are many, many lines to check, but start with the pump itself. You may be able to do a site search to help with different sections.

Vacuum leaks are a pain in the arse but can be found by isolating the various circuits. First thing you need to do is find a Vacuum diagram for your vehicle on this or another website...

Each system works independantly of the other but all are fed by the same pump. For example, a leak in your doorlocks wouldnt necessarily make a leak in your brakes. Heres where to start...

1. Check for vacuum directly off your pump (I believe this works because you can STOP!)

2. Remove the recieving end of a vacuum line to a component and check the vacuum (for example...take off the shut-off valve line and check the vaccum pressure there) do this to as many systems as you can access comfortably and see what your readings are.

3. Ok, so everything is normal vacuum wise...lets move on to the actual components... I had a stop-valve go bad...so many times, these delicate diaphrams can leak...make a little vacuum pressure on a component and then see if it holds the vacuum...if it doesnt...leak!

4. Also, look for what we call "red flags" in the system...these are lines broken, cracked, or downright missing. Over the years, they can dry out or be knocked off and broken...look for that before condemning parts.

5. Want some vacuum line but dont wanna go to Merc? Take a piece of 10 ga solid copper wire and strip the sheathing off an individual strand...it fits perfectly as vacuum line and stands up to the heat (did it on mine...10,000 miles later...still good!)

Do that and tell me about the results...remember, the Mity Vac is INVALUABLE for a diesel mercedes!

I tried the WD-40 in the lock trick and it worked like magic. Now my trunk opens every time no problem. I found one definite problem with the vacuum system a hose that is only in loosely but it won't go in any tighter so not really sure what to do.

Where is this located? Replacing the rubber connectors usually will help.

Whats the WD 40 trick. The vacum lines in the engine bay have been cut and spliced, so i need to do a whole replacement.

If the red brake light is on it could mean the parking brake needs to be adj.