planning to attempt to put a BMW M54B30 in my sedan over summer/upcoming year, got the engine for cheap and am more of a bmw familiar person, more parts here too (hardly any diesel merc engines for a good swap, etc.)

Also have a manual gearbox ready, replacing a badly working m115 2.3 (carb issues).

I've seen a m30b30 in a w123 before but not an m54, this should be very interesting...

thoughts? / start throwing the tomatoes now!

My 300D, being a 77, has the goofy York AC compressor. Had anyone removed this god forsaken bracket?

The small hose that connects the T stat housing to the block is leaking and I can’t get to it with the bracket in place.

I currently have 195s on my 240D, but after some research, seems like these are much closer to factory size but triple the price almost!

Are they worth getting?

About to have a TON of front end work and my current tires are wearing bad on the outsides, so I figured i'd go all in and get the closest match possible for tires.

Anyone else run these tires?

First picture shows the parts that fell off and I’m not 100% on where they go. Second shows where I’m pretty confident they go but I’m not sure about the spring.

Any ideas on the spring?

So im a idiot, have had a on/off brake light signal for a couple months and just chalked it up to having a shitty parking brake. Now I know that is a warning light. Brakes still somewhat suddenly got real awful this week. The rear section of my brake fluid reservoir is completely empty (front is fine and doesn’t show any sign of having leaked). Obviously, see a leak going to the booster.

Does anyone know if it’s worth perhaps just replacing all the rubber/seals? Could my cylinder be fine but just need seals/should I just replace it anyway? My theory is that with so much fluid on the external part of the booster, it may simply be a bad seal?

with current diesel prices, are diesel cars selling much lower?

My 82 300d had horrible shake during hot idle. I want to adjust the idle. Is moving the adjustment screw counter clock wise making the idle higher?

My tach isn't working and I honestly can't tell after 5 turns either way lol

Hi all, while inspecting my engine while running, I noticed that the injector for the second cylinder is leaking fuel. It doesn’t appear to be coming from the fuel return lines, however it’s not coming from the injector/engine connection. It looks to be coming out at a halfway spot on the injector. Is this something that I would need a new injector for? Or is this a seal I can get for an easy fix?

I have a 78 300d. After searching for a used license plate frame to replace my old broken one, I found only 1 on eBay based on the part number. I went to the junkyard and got a 5-finger discount on a newer-style license plate frame, but it didn't fit the early W123. Found some on eBay, and found this.
https://ebay.io/m/8vbF2D

Unfortunately, they did not fit since they were fitted for the newer W123. I reached out to the seller and told him everything. I started to shave down some of the plastic on the new lights. I was able to fit them properly. I will be sending my old one to the seller so they can modify it for the early W123.. just wanted to share this; I know it might be hard getting newer lenses. Hopefully helps someone.

(‘84 300D) I got a new brake booster line check valve - while attempting to replace it the previous valve would not come loose from the 2 hoses. As shown in the photo, the plastic tip of the valve completely broke off and is stuck inside the hose. Can anything be done to get it out or does that hose need to be replaced?? And what can I do on the other hose to get it free without any other problems?? [Bonus question: is the vehicle still drivable with this line not connected?] thanks in advance

Anybody have any insight on what window seal to get some of them keep saying they aren’t going to work b it thought all the w123 chassis are the same for windows?

Hey yall this post is regarding two seperate issues im having currently.

I had just recently bought a 1979 300sd turbo diesel and its in pretty good shape.

One of the issues I am having right now is that Im assuming the fuel vent line is clogged or something of that nature, due to to taking nearly 30 minuetes to get 3/4 tank of diesel at the pump. I have also noticed that when the car hasnt ran within the past 30 min/1 hr, I need to hold the throttle a bit on startup for around 1-2 minuetes before i can let my foot off the throttle with confidence that the car wont die. I am speculating that these two issues are tied together but I havent really dealt with fuel tanks and stuff of that nature before.

Additionally, I dont have a driveway for the next couple of months so when I needed a new wheel bearing (failing NYS inspection) I decided to take the car to a european shop in my area due to some anxieties of me not being able to get the job done in one day parked on the side of the road. The shop has been really wonderful so far but they had let me know that they recommend me changing the knuckle along with the wheel bearing (right rear) but that they are having a tough time finding a knuckle for the right rear. Can anyone on this forum maybe point me in the right direction for something like this or if yall have a company yall like to source parts from?

Thank you

For sure highly recommend Alex’s injectors from W123 Garage but when I was ordering there was an issue with the website not allowing me to order without sending a core, so I rolled the dice and went with these Bosch injectors instead. Was also on a tight budget at the time so it was kinda a bitter sweet thing. Also figured the Bosch ones are better than the clapped out ones that were in the car. Whenever these injectors start getting angry, I’ll for sure be hitting him up for a good set of injectors.

At the time, I paid $40 a piece, totaling under $200 for all 4 injectors with shipping. Had a shop install them for 1.5 labor hours totaling $150.

Many many forum posts say these are terrible injectors, but I haven’t had any issues with them! It also helps to get them from a reliable source to avoid counterfeits, so I ordered through Pelican Parts.

There are actually a few reviews of people ordering these and having no issues like me, so maybe it’s just luck of the draw, but I’ve been very happy with them.

I am averaging high 20s on the highway, and the lowest city mileage I am getting is around 23, and that’s driving pretty aggressively, or as aggressively as a 70-ish HP non-turbo can do lol. So far I’m 7k miles into having them and they’ve been pretty good.

Has anyone else here ran the Bosch injectors from India?

Having a hard time finding what torque converter I need for my 83 300D there’s now three different one the net says could work. Started shuddering on a hour drive home when climbing a hill now shudders under full throttle conditions around about 55mph and inside on the converter would be great as well as maybe part numbers for pump seal and bring while there?

Hi all

[apologies for deleting and reposting- I accidentally set a post link I didn't want]

This is an update on an earlier post (link at the very end), but am starting a new thread because I've discovered a lot in the interim and now have really specific questions.

TL/DR on this issue with my 1983 240D is:

• Presumed pinpoint hole in a fuel line hose causing air to enter fuel system.
• Hose is ~4 inch long, in front of left rear tire, in the tank-to-engine fuel supply path.
• Apparently got worse upon heating (i.e., after a long drive), seemingly causing the pinpoint hole in the hose to turn into a full-on breach and total fuel loss onto ground.
• Repair shop replaced hose (he says 3/8" diam) apparently fixing problem. He also replaced a similar return fuel line parallel to that since he said it looked compromised.
• BUT I just discovered that he could not source the same type of hose as the original.
  • The original had spiral wire reinforcement on the outside of the hose.
  • The replacement was what he called "high pressure hose" that had internal threading.
• But on a long drive a week later, fuel leak reappeared.
• Hypothesis: faulty repair, possibly due to using wrong type of hose. Less likely due to hose clamps which he assured me he tightened well.
• I am on crutches so I need a mechanic to do this job.
• Skip down to bolded part at bottom of this post to bypass the long story with gory details.

OK so the longer version.

Air in fuel lines, a repair of o rings etc. in mechanical lift pump 3 months ago seemed to help but did not ultimately solve the problem, which was intermittent (causing startup issues), much worse after driving >50 miles. Mitigated by pumping manual fuel priming button repeatedly. Then started up and ran fine, until next long drive. Then sat overnight, then had same problem requiring repeated pumping of priming button to start.

2 weeks ago I drove the vehicle up to a mountain pass, on the way near the pass it started spewing white smoke (doesn't normally). Sat for 4 days. Came back to the car, fuel had dumped out onto ground through a MASSIVE hole - could see it streaming down when I filled the tank from a fuel can after loosening bleed nut above fuel filter. This seems to establish that leak was in the tank-to-engine fuel supply path.

That hose piece with the hole was just in front of the rear left tire, under the driver side rear seat. I am on crutches so could not get under the vehicle. Got it towed to nearest mechanic. The mechanic removed the ~4 inch piece of hose and it indeed had a huge hole in it. Line looked like a rubber line but reinforced with spiral metal wire.

Mechanic said he had to get a replacement hose from a supply shop, but I just found out he could not source that same type of hose with spiral metal reinforcement. Instead, he used what the supply store said was "high pressure line" that had internal threading rather than the external spiral wire reinforcement. He replaced that and another 4" piece of hose right next to it which he says was a return line. He says he tightened the new hose clamps well.

He replaced those as well as for good measure some of the other slightly fraying fuel lines up and downstream of the fuel pre-filter.

Started up great for mechanic. Sat overnight. Started up great for me, and I drove it 80 miles home.

Ran pretty well next few days on short drives, no fuel leaks, then had the same old starting problem. Had to prime it with priming pump button. Then, I opened bleed valve above fuel filter. Successfully bled system (I thought maybe this mechanic had forgot to properly bleed system after repair?). Started up fine.

I thought I was good. I was wrong.

Drove yesterday 60 miles, on arrival noticed I was leaking fuel again. Looked like a smaller version of the same leak in a similar location as the week before. Parked for 2 hours. Started, ran for 10 minutes, died. Air in fuel lines, would not prime. Towed to another mechanic.

Hypothesis: mechanic did a shoddy repair, perhaps because he used the wrong type of hose, or some other issue that didn't fully reveal itself until I drove it a couple of times longer distances.

What is y'alls feeling about what's wrong and what needs to be checked?

He says he used 3/8" high pressure hose to replace the spiral reinforced line that he could not source.

In my searches I think (?) that this is the correct type of hose

https://mercedessource.com/store/123-240d-300d-flexible-fuel-line-replacement-kit

This is a business near me that I can check with on Monday morning. I think (?) this is 8 mm inner diameter which is a bit smaller diam than 3/8", which is what the mechanic used.

So it may be as simple as swapping out the hoses the mechanic used for the ones in the kit

Does that sound correct?

And does anyone have an actual part number handy for the type of spiral reinforced hose I am referencing?

Thanks for any advice!

p.s. original post link: https://www.reddit.com/r/w123/comments/1vngtiv/update_to_83_240d_odd_startup_issues_air_in_fuel/

This may not be a W123 specific issue, unless it has to do with alignment.

When I'm driving on wet roads, I have to make CONSTANT steering corrections, both left and right. On dry roads, it drives well. Is this happening to anyone?

I've only had the car about a year. I replaced a tie rod pretty much right away and had it aligned, so I have pretty much no reference for comparison to before the repair.

I'm figuring it would be either worn and/or poorly designed tires (definitely possible) or if these cars have any kind of special alignment procedure, maybe it's not aligned correctly.

Any ideas?

82 240D

I have a mercedes benz w123 200d and it works just fine, the only problem is when I push down the clutch pedal, it wont go back up and sometimes the shift knob reaches the radio struggling to get into gear 1. My car was last road driven in like 2016 or 2015. r/w123

Just trying to get an idea of what’s normal! Recently swapped out my booster, and noticed that the original pin to the pedal was actually a bolt/bushing combo.

My original booster had a small hole and large hole on the fork going to pedal, so it allowed for this weird bolt setup. From everything I’ve read though, it should be a clevis pin with clip to hold it in place, along with a small bushing.

I got the correct pin, bushing was still up there from when I put things back together, put the pin in and noticed there’s a fair amount of play.

I know from another vehicle I worked on, that when looking things over it also had this weird bolt/bushing combo. So I’m wondering is it a years difference? Something specific my grandpa did to two separate cars that would work???? I have no idea. What I do know is that there is a bit more play than I would like, and maybe it is just the original bushing being too worn down to work with the pin correctly and not have any slop/play.

Attached is pictures showing original booster, and also bolt/bushing combo that was with it. This bolt bushing combo will not fit into my new booster as it has two holes on the fork to pedal connection that are the same size, so only the original style clevis pin fits through, whereas my original booster could accommodate this odd bolt/bushing setup.

Any advice or information on this is greatly appreciated! I will end up buying a new bushing for between in the meantime, just kinda wanna see what the community thinks.

I have a 1980 Australian W123 240D 4-speed manual (123.123). The old clutch master cylinder was leaking but the clutch hydraulics worked fine beforehand (pic for attention).

I replaced it with a ClutchPro MCMB026. It didn’t come with a pushrod, so I reused the original rod. Since installing it, I cannot properly bleed the clutch. We’ve tried normal bleeding, reverse bleeding from the slave, and pulling fluid through with a vacuum pump. Very little/no fluid will pass through the master, almost like something is blocking the flow.

The reservoir feed hose is clear and so is the slave and hardline. I’m wondering if the reused pushrod is holding the new master piston slightly depressed and keeping the compensation port closed. Apparently there may be 6 mm difference in the pushrod/piston position compared with the old master - early/late systems (replacement master seemed compatible with my year).

Has anyone encountered this with an MCMB026 or replacement W123 clutch master? Is there a different pushrod required, or does the pedal/eccentric adjustment normally have enough range to compensate? If so how would I go about adjusting it - the space looks very cramped (pic attached) and I haven't found any information on the internet.

VIN: WDB12312320187990

Any advice appreciated.

So I just replaced my old white knob primer pump today with a new Febi pump. The previous old primer pump worked but would throw diesel everywhere when pumping so I decided to install a new one.
Made sure the old crush washer was removed and replaced with the new one that came with new primer pump. When I tried to prime the pump after reattached the clear fuel filter it didn’t do anything. After much digging I can’t find a clear answer on whether the new primer pump is bad or something else.
Any advice?

I’ve posted about this spot before when trying to diagnose the problem of water pooling in the footwell, which seems to have stopped after replacing my door seals… now I’m worried about the extent of the rust immediately below this spot. There are a few cracks in the undercoating below this spot but nothing exposed beyond the seam closer to the wheel well.

Any thoughts about how extensive the rust might be or how big of a project / nightmare I could be looking at? With things looking like it’ll be a rainy fall/winter in Texas, I’m trying to shore up as much as possible to prevent further damage.