1981 240d questions - PeachParts Mercedes-Benz Forum

Jason Beal · #1 02-06-2003, 08:05 PM

I just got a 1981 240d/stick. It has a few issues, but runs pretty darn well. I had a few questions I hope you can help.

1) Are all locks supposed to open/close when I use the key in the drivers/passenger door on this model? Mine don't but I'm not sure if they are supposed to.

2) Went to crank her today to see if she would. She almost did, but pooped out on me. She started fine the other day @ 40 degrees, but today at 25 she wouldn't go. After three attempts I began to hear a clicking sound on drivers side next to fire wall. What could that be?

3) Where does a block heater hook up? (When I buy one)

Thanks for any help. I drove her an hour home no problem after sitting in this guys driveway for four months. It needs all the fluids/filters changed but it's too cold right now to be outside for a long time. I wish Spring would hurry up so I can get started on this thing. I'm thinking she needs some fresh fuel too.

#2 02-06-2003, 09:13 PM

Yeah, all locks are supposed to work. They're vacuum operated--you'll have to trouble-shoot the system.

Don't know what the clicking might have been. You probably want to check the glow plugs. There's a relay on the drivers side in the engine compartment--could be bad. Or the glow plugs could be bad.

The block-heater is on the passenger-side of the engine, near the rear of the engine, right behind the starter. You may (or may not) have a block-heater installed. Check for wires coming out--they'll go to the front of the chassis, usually right under the front bumper, right side.

Hope this helps.

dave240 · #3 02-06-2003, 09:20 PM

Jason,
Congrats on the new car.

On my 82' 240 the driver side door key does control all locks. would assume same for 81'.

Block heater on my car is next to the starter. if there is not one installed, you will see a 1 3/4 inch threaded plug with a 19mm (same as 3/4in.) hex.
If the heater is installed but missing plug-in cord you may just see the pins there were the cord should be plugged to.

The driver side fender well is where the glow plug relay is mounted on my car. Check the fusable link (50 amp I think) located under the relay cover. You can find your relay by following the wire back from the glow plugs. You can by pass this relay I understand by bringing 12volts from the battery. and disconnect after car is running. DO a search for more info on that.

Starting problems can be many things, however, if the car started fine in 40 deg. weather I would start with thorough check over glow plugs & relay.

good luck
dave

Jason Beal · #4 02-06-2003, 11:41 PM

Thanks for the replies. Now I remember what I meant to ask, but couldn't remember before.

When I turn the key to the number 2 position, the glow plug dash light is supposed to illuminate on the dash? Then when it goes out it is ready to crank? Is that correct? I don't see anything light up when I put it in the number two position. Could that be the glow plugs themselves or the bulb that lights up on the dash? I know zero about these diesels, so sorry if this sounds dumb to you guys.

Stevo · #5 02-06-2003, 11:52 PM

Jason

Good score

. Lots of 240d folks around here. do you have any manuals yet? The Haynes Manual covers most of the things you will be concerned about for now I would think.

as to your starting problem, like Dave said "could be lots of things" but most of the time its glow plugs at least thats what I would think of first. You need a strong starter that turns up 100 RPM min and a good battery. When you glow it your dome lite should dim which would tell you the GPs are getting juice. If your priming pump leaks when you pump it or you have any fuel leaks from old hose, that could be the cause of air entering your fuel system, causing hard starting. The upgraded priming pump is less than $20.00. If the car sat for a while you should change the 2 fuel filters for sure and look for goo that would indicate algee in the fuel, probably wouldn't hurt to dump a can of treatment in the tank. Plenty of good info in the archives as these problems are pretty common. Vacuum leaks and no start, oh ya, been there. Best of luck and congrats again

#6 02-07-2003, 07:51 AM

The glow-plug light not coming on is usually the sign of one or more bad glow plugs. Do a search "glow plug light" of the diesel forum and you'll get info on checking and replacing them.

#7 02-07-2003, 08:58 AM

Your car is a pin type glow plug system. The glow plug relay uses number one glow plug as a temp sensor by measuring the current through that plug to determine when to turn off the dash light.

Start troubleshooting by putting a voltmeter on one of the plugs. If there is voltage then replace all four plugs. If there is not voltage, check the 80Amp bar fuse in the relay. This fuse will often look good when in fact it has vibration caused stress crack that is difficult to see.

If the glow plugs work okay, but the dash light still does not come on, check the bulb in the dash light. Remove the kick panel below the steering wheel and reach up with your hand and push the instrument cluster toward the steering wheel to get it out far enough to access the lamp.

Good luck,

Aaron · #8 02-07-2003, 09:02 AM

If the car has been sitting for four months, go through the standard "service" as follows:

-New battery
-New fluids and filters (engine oil, gearbox oil, coolant, brake fluid, differential oil)
-New glow plugs
-New belts
-Valve adjustment
-Perhaps new water pump and thermostat

I always recommend buying these kinds of service parts through your local MB dealer, because you know they will be of the highest quality. Don't let $400 or so worth of parts and fluids get you down, at least it'll all be done in one shot and you won't have to worry about any of these items for a while down the road.

Use a good 10W-40 oil such as Castrol GTX and buy one or two extra quarts in case she's an oil drunk

**I might also add that it would be wise indeed to run a bottle of Red Line 85+ or Diesel Fuel Catalyst through the fuel system (just pour into the tank). You can get that here through Fast Lane. 85+ and Diesel Fuel Catalyst are one and the same product, the name just changed and I don't know whether or not Fast Lane sells it as 85+ or DFC.

leathermang · #9 02-07-2003, 10:25 AM

Aaron, new radiator hoses would seem a logical addition to your list....

Jason Beal · #10 02-07-2003, 12:55 PM

Wow. I can't thank you all enough. That answers every single thing I need to know. I'm not too concerned about the extra $$ since I bought it for 500 bucks. The kid just wanted to get rid of it since he was just married (his wife hated the car) and has a baby now. His father owned it for 14 years then gave it to him. He said it never left him stranded. But the new Jetta he bought at his wife's instistance has left them roadside twice so far. It has a new exhaust sytem, new starter, alt, new tires and battery. I can gladly tackle the rest on warm days since I didn't get a garage built yet. Thanks again for all the info, I couldn't own an older or new Benz without this site. She should be rolling well by April.

engatwork · #11 02-07-2003, 05:13 PM

Here is a shot of the block heater where it screws into the block. Disregard the turbo located at the top edge of the photo

on the 240D.

The drain plug for draining the block during a coolant change is located toward the lower right in the shot.

Stevo · #12 02-07-2003, 07:26 PM

Jason

I see your not sure of the millage. If your odometer and trip odometer are TU, thats a common problem and when you get all the priority stuff fixed there is a fix for that. $500.00 was a good deal and even if you wind up spending money to get everything right you'll have a nice car with new replacement parts. Plus they are fun cars to work on because allot of the parts can be taken apart and fixed. It would be good to adjust the valves on the sooner side as they tend to get tighter if neglected. I had to replace the cam and lifters on my daughters 240D because of that. Your car has the hardened cam and lifters being post "80" but still would be a good thing to do if you can swing it.

Jason Beal · #13 02-08-2003, 02:06 AM

Thank you again for the picture.

I can do all the work myself once it warms up. Like I said, it drove real nice both times I drove it. It didn't pull and idle was fine, seemed rather peppy once I got her into 2cd gear. I read up on the odometer thing. The PO said that it went out three years ago. It's showing 156k miles now, so it can't be that high. The inside is in great shape, but there is some rust along the bottom. I plan on just having fun with this car and enjoy driving her around when I can. I have wanted one for so long and walked away from a few that seemed like they would be money pits. Next couple of years I'll try to pick up a cherry one and try to keep her until I'm an old man. Right now however this is the perfect car to have fun with and learn.

I really can't say thanks enough. I'd like to post a pic, but can't figure out how to compress my pics (new digital camera) so once I do, I'll post a pic.

mikemover · #14 02-08-2003, 07:48 PM

Quote:

Originally posted by Aaron
-New battery
-New fluids and filters (engine oil, gearbox oil, coolant, brake fluid, differential oil)
-New glow plugs
-New belts
-Valve adjustment
-Perhaps new water pump and thermostat

I always recommend buying these kinds of service parts through your local MB dealer, because you know they will be of the highest quality.

Hi Aaron,

Is there a particular reason you would suggest buying these items from a dealer?

Here at Fastlane, or one of several other sources, one can get the exact same OEM parts for FAR less than dealer prices! I ALWAYS use top-quality, OEM parts, and I have NEVER bought them from a dealer and paid dealer prices.

Just wondering...
Mike