Introduction and General Advice on 240D
 

Hello, my name is Mark and my first car was a 1981 240D. I bought it in Oakland and kept in the Bay Area for four years before moving it to Las Vegas where it has stayed with me for eight years. I love this car and have just as much fun driving it as my Honda S2000!

The PO took out the A/C condenser when he changed the radiator. His wife didn't want it anymore and he sold it to me for $800 after replacing the transmission. Without the A/C, I only drive it in the winter here. Last winter, some issues began making the car very difficult to deal with, but this year, I'm doing things to it that probably have never been done and getting it running right.

New shock absorbers (looked like originals were still in)

New sway bar links

New bushings in the front suspension (again, everything looked original)

New engine and transmission mounts

Rebuilt fuel injectors with Monark tips

Replaced all filters and tank screen (inside of tank looked brand new when I got in there!)

Removed, cleaned, replaced fuel level sender (seems to work for the first time in 12 years!)

New oil pan and gasket (old one was all banged up)

Adjusted throttle and Idle linkage.

New bushings for the shifter linkage (there was literally nothing there!)

New glove box door, instrument cluster housing, and driver's door from junk yard (I have an armrest now!)

New headlight, turn signal housings

New grill trim

Replaced all brake and clutch cylinders
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Here are my remaining issues;

1. No A/C. First here, but very low on my priorities.

2. Needs new rear axles

3. New steering linkage and probably a new gear box. I have play in the wheel, but only to one side, and I noticed the gear box is leaking onto the pitman arm. I am NOT losing fluid from the reservoir however.

4. It takes two glow plug cycles to start the car without having to floor the pedal. I've only replaced the glow plugs once since I've had the car and that was about four years ago. I will get new plugs and the reamer to clean them since it was probably never done.

5. Three of my rebuilt injectors just developed a leak. My original plan was to take them to a diesel shop to make sure they are at 115 bar and leak free after everything else was done, but looks like I better do it sooner.

6. Really bad vibrations after new engine mounts. The shaking stopped though :) The mount that goes next to the oil pan, was completely disintegrated and the new one doesn't actually make contact with the bracket it sits in. I'm hoping if I order a new one it will be thicker and stop the vibrating, cause I can feel it in my skull!

Thanks for taking the time to read this, and any help or advice is greatly appreciated! I know absolutely nothing about cars until I need to fix something. I do all my own work if I can and it is ALWAYS fun for me to learn about these cars and then work on them. There is something special about knowing my old Mercedes runs only because of the effort I put into it.

9 out of 10 times leaks around the injectors is just the return lines. I would replace them first and clean the engine before rebuilding any injectors that are suspected of leaking. If A/C is needed, I suggest replacing the condenser with a parallel flow (cheaper than OEM, and more efficient). Then I would go with a Sanden compressor instead of the R4 (pretty much junk from the factory IMO). A good A/C system is needed in the summer when in Vegas......Rich

Thanks for the reply. The lines are all good near as I can tell. The injectors are leaking right at the seam. I wiped them down with the engine running and watched them pool up. The number one leaked before I rebuilt them, number three leaked after. Now, after about a month, number one is the only one NOT leaking. Cracking the hard lines makes each injector run rougher, so I guess they're all working well enough to get by for now.

Rebuilt injectors will need, or should have been done anyway, to be lapped.

Once the two halves are removed, on a flat surface on lubed emery cloth drag the open ends. This will help to have nice flat surfaces when reinstalling.

I thoroughly cleaned and lapped them, one of them twice. Maybe I just don't know what I'm doing.

Okay, perhaps more torque to seat 'em.

An A/C unit on a 240 will really slow you down, just keep that in mind.

did you replace the crush washers and torque both halves together as well as the injectors into the pre-chambers?

I would never change all the glow plugs as preventative maintenance. I just change them as they fail. Every year or so, measure resistance to ground at the connector. As I recall, all I have found bad in both 300D's have been Bosch to date, but then both cars probably had Bosch to start. I don't recall a cheap one from ebay (CYP or such) failing yet.

If you still have the compressor (York?) and brackets, then getting the AC back shouldn't be hard. Many here change to a newer and better "parallel flow" condenser, so read posts. RollGuy might be able to sell hoses that fit. I would remove the compressor, drain the old oil. I use DuraCool refrigerant in most cars and their PAO 68 oil. Enviro-safe is another R-12 replacement.

Is the pre chamber nut tight? I had one loose and it leaked past the connection between injector and prechamber.

If you research those compressors a lot of info comes up. There's something you have to do to the fittings for the lines. I'm just gonna do all new ones. Still researching.

Test resistance on glow plugs and wiring

That motor may be tweaked from a bad mount. You could loosen the tranny and front mounts (if applicable) and the new motor mounts as well. Grab the head and literally shake the whole thing. Should settle down flat.

Make sure you have the right mounts.

...problem is, if you live in a place that genuinely gets cold, having a bad glow plug can keep you from starting the engine.

Thanks for all the input. For the injectors, I decided to replace all the hoses, check the collars, and take the injectors to a diesel shop. Those heat shields have been on less than a month, do I need to replace them again when I take the injectors back out, or would they still be good?

Ah the glow plugs... I believe they are Bosch. I was looking at a website that has Monark plugs with the reamer. They definitely need to be cleaned out from what I've read.

I just came back from a really nice shop I found that loves working on these old cars. The steering linkages are all really tight still, but the damper is shot. He said they would rebuild my gearbox and reinstall for me. He has a 300D parts car with a gear box I can use as well. He quoted me $590 to rebuild and install my axles, and install a new differential mount.

The heat shields are a one time use item.

Quite possibly they will deform to the particular pre-chamber in the rotation torqued.

Introduction and General Advice on 240D
 

I read bad reviews on the monarch glow plugs for the 21mm pencil type. Not sure about others. I bought Bosch. You can make a reamer from an old plug they say. I had my head hot tanker so I haven't looked into it.

I replace all at once also. Drives me crazy to mess with it. Save the old ones as spares.

I just paid $170 to have my axles rebuilt.

Prob took an hour to go in and out.

Mount is removed at the same time.

Check out mount prices.

That sounds about right for a shop. Getting axles out was intimidating.

So I have got all the fuel leaks stopped and the car idled and ran beautifully.

I was driving home from work and my oil pressure dropped from 3, down to 1 1/2 under load. I was on the free way and had no loss of performance until my exit. The pressure was almost completely gone at idle and the car stalled. I coasted to the side of the road and waited about 20 minutes. I added 2 qrtz of oil and she fired right up. I drove 3 blocks home in 1st gear and parked it. The temp never went above 95, which is what it ran at before the coolant flush.

I installed a new oil pump and the pressure when straight to 3 when I fired it up. I let the car idle and warm up while I put all the tools away. Then I went for a drive and wound up stalling again after about 20 minutes. My phone was dead and I didn't have my wallet so I abanded the car and came back on hour later to drive it home.

Oil pressure is good. Fuel filters are good. Coolant level is good. Engine sounds the same it always has. Valve clearances are good. Timing chain looks great and show just over 5 degrees stretch.

I can't lower the idle nearly as far as I could before. The car feels incredibly underpowered and there is a TON of white smoke leaving the exhaust.

Any ideas? I'm leaning towards the fuel timing being off. Any chance the low oil pressure could have affected the tensioner enough to have the chain slip?

Running the engine out of oil, really could have damaged any number of things....

White smoke, is usually an indicator of a blown head gasket...

You may be needing to look for a new engine now.....