A few months ago I picked up a 1987 300E for about 800 bucks in non-running condition. It had been sitting for 4 years due to a misfire that the mechanic couldn't figure out, no idea why. She wanted 1500, then dropped to 1100, and I offered her 800 telling her I would fix it up to be my daily. I figured the M103 was both cheap and pretty bulletproof, and for 800 bucks the body looked pretty clean and there was probably an ignition or fuel problem somewhere, and worst, case, an engine rebuild wouldn't kill me.
Here's what it looked like on day 1 getting towed to my house.
The aftermarket wheels were hideous. The springs looked like it was a safari build, and even though it looks ok at a distance, some of the paint was fairly oxidized.
I immediately jumped in to diagnose the no-start issue. I started by ordering everything cheap in the fuel and ignition system, fuel filter, spark plugs, distributor cap and rotor, seals, etc. I drained the fuel and replaced the battery, changed the oil, and honestly - the pumps didn't even look that old. When I pulled the plugs I noticed they were two different brands, and also that they were resistor style plugs, and that car needed non-resistor types.
So I replaced the consumables, dizzy, cap, rotor, spark plugs, battery, and turned the key and bam. Running car. Drunk on my own success I raced off to find wheels that didn't look like they were bought at a roadside flea market. I lucked out and found some Monoblock IIs with some light curb rash and new tires for 700 and I jumped on it.
Instant improvement, the ride height still looked like (apparently I can't type swear words on here) though.
I started taking it on short test drives, and noticed that the entire car would shake when I applied the brake hard, and it drifted along the highway so much at speed that the only way I could have looked like a sober driver was if I were actually drunk.
After 2 Googlings I decided to drop the subframe, and found bushings that looked like this:
And like this:
So I decided to redo the entire suspension, front and back. I bought H&R lowering springs, Bilstein sports shocks, all new control arms - ball joints, end links, brakes, rotors, parking brakes, brake lines, subframe bushings, subframe mounts, diff bushings, diff mount, rear bearings, sway bar bushings, steering damper, trans filter and seal, valve cover gasket, and because I'm shallow and basic, I also got euro headlights and polished the paint.
One thing I learned is that when something like lowering springs says "6 in Stock" on eBay, it doesn't actually have to BE in stock. So the springs were going to take a month to deliver (thanks COVID).
I was EFFING FURIOUS because I thought that was going to be way too long, and I would have the subframe done in a jiffy, and I'd have to cut the stock springs in the meantime, but as usual, I vastly overestimated my mechanical skill and my springs were actually in my house for a week before I got around to put them in.
Here's a picture snapped by my neighbor of me being pissed about what a pain installing the front ball joints was.
Right, so I finally got it all back together and I took it to Les Schwab to get it aligned because, even though I fabbed up an alignment rig for my other car (shown below) - I was honestly bloody tired and didn't really want to deal with it anymore. Except Les Schwab had no clue what they were doing because I was sitting there looking at my rear wheel toe and my front wheel caster and it was definitely totally out of whack (1/4" rear toe in, wth?) and they were insisting it was aligned ("See the sheet?! Aligned.")
So I loosened up the cam bolts and put everything roughly neutral, stuck it up on my rig anyway, a hundred or so dollars poorer but too pissed to try Les Schwab again even though I had a "warranty". And got the alignment pretty dialed in. Not overly concerned with getting it perfect because I had camber links and a camber adjustment kit for the front and back coming in from Poland, and Discount Tire Direct had a fire sale and I scored some new tires. Which aren't installed yet until I sort out all of the camber settings, and roll the fenders.
I spent a ridiculous week chasing down an issue where the car would change thrust angle and sort of track differently when the transmission kicked down at speed on the highway, and just as I was about to quit and take it to a suspension shop, I decided to put it up one more time and noticed that the passenger side rear wheel was moving more than I would like when I gripped at 3 and 9 o'clock.
Getting under the car, I noticed the toe link on that side had some play at the ball joint. In my fear of overtorquing the ball joint bolt and crushing the boot, I under-tightened, and my rear toe was effectively changing when the rear wheels got a lot of load. Boom. Fixed.
Here's my alignment rig on my other car.
So that brings us to this morning. I took the Mercedes out for a spin on the highway in the morning, and it finally felt rock solid. I ripped out my lighting relay which had some cracked solder joints causing a side-marker light to flicker, and replaced the blower regulator so I could finally get my climate control on track (AC still not working, probably refrigerant, or another relay).
Also, I definitely need to roll my rear fenders because the tires are rubbing slightly.
But here she is, looking like (to me) at least ten thousand bucks - and definitely too high-class for the likes of me:
Dat a$$
Which brings me to the selfish reason I am posting on this forum, because I've reached the limit of my mechanical expertise. Unfortunately this car is not yet cool enough for amateur losers like me to really get into the heavy mods, so even though I've searched through threads high and low, I can't find a dumbed down explanation of what I want to take as my next step.
1. (2021) MS2 fuel only. 2. Late 2021 or 2022 dizzy-less ignition 3. (Late 2022 and probably after a top end rebuild) Turbo with a 300-350 HP target
I need help on #1.
So - I've looked on Peach Parts, the MS forums, Benzworld, and while there are a ton of threads on people doing Megasquirt, nothing really outlines what it looks like soup to nuts, so I guess I want to be the first.
As far as I can tell, I need to get a fuel rail with injectors, solder together an MS2 unit, get some cables and tuning software, and then things get a bit fuzzy.
I THINK for fuel i need a MAP sensor, installed past the throttle body in full vacuum and a wideband O2 sensor. Maybe a TPS stuck onto the throttle. But then I see some threads that talk about swapping out the flywheel from a 3 tooth to a 60 tooth - which apparently bolts on, so the CPS can get the right signal to the ECU, but I THINK that's only for ignition (which is my second step). But I can't make sense of it.
Can anyone point me in the right direction?
The Mercedes dealer is the best place for an alignment on these cars.
Cross your fingers the AC evaporator is not toast as it is a lot of work to remove dash and associated parts.
Where are you located? I have a friend in MI who regularly converts these to megasquirt and can put you in touch with him.
Forgot to mention M103/M104 build group on Facebook is also very worthwhile joining
Good looking car! And what a hell of an improvement. Manual?
ccrelan (Forum Supporter) said:
The Mercedes dealer is the best place for an alignment on these cars.
Cross your fingers the AC evaporator is not toast as it is a lot of work to remove dash and associated parts.
Where are you located? I have a friend in MI who regularly converts these to megasquirt and can put you in touch with him.
Thanks! I'm in Oregon. South of Portland. Mainly I'm just looking for an overview of the parts and sensors I need and whether or not to go ahead and change my flywheel.
I did read through the MS manual but honestly this is going to be my first foray into how an ECU works so it's all new to me.
iansane said:
Good looking car! And what a hell of an improvement. Manual?
No! I thought about doing the swap but the manual actually can't handle the horsepower I want and really I have a manual sports car and I really want this to be a cruiser that doesn't get totally lost in the curves and has a little oomph.
I think I spy downtown Lake O in some of your pictures(?). I have put Les Schwab on my lifetime boycott list. They stopped being a great company shortly after the old man passed away.
Sparkydog said:
I think I spy downtown Lake O in some of your pictures(?). I have put Les Schwab on my lifetime boycott list. They stopped being a great company shortly after the old man passed away.
Busted! Yeah man. Lake O lurker here. I live in river grove.
ccrelan (Forum Supporter) said:
Cross your fingers the AC evaporator is not toast as it is a lot of work to remove dash and associated parts.
I'm reasonably certain it's a leak, or a relay issue, because the condenser fan isn't kicking on. But yeah, if it's the evaporator - well, Oregon winters are a pretty good time for projects.
This is a great GRMer pcture!
Are the neighbors tolerant of your shenanigans? Gutsy to tear it down right in the road. For me, it might be there a few days in that condition if I run into a snag.
In reply to Kyngfish :
I know the current "mayor" of River Grove!!!
I've owned a few manual W124 and W201, and I wouldn't bother pursuing manuals in these cars either. I was pretty disappointed as a whole.
As for your question on how to proceed: you mentioned reading the MS manual. You need to really *study* the Mega Manual. It's amazingly detailed and has all the answers to your questions. I'd do fuel and spark at the same time. Plan on a full suite of sensors and triggers: crank position, cam position (the distributor might be the easy option here since I don't recall a provision for this on the M103 but I could be wrong here), MAP, TPS, Coolant temp, air temp wideband, etc. You *can* do fuel only with more crude triggers, but might as well go straight to the 60-1 or whatever the factory used on the M104 since your upgrade path already indicates the need.
Beauty of a w124 for that price! These cars are just that perfect era of MB between the looks, reliability, availability and price.
And those wheels that came on it... ewww.
In reply to John Welsh :
Hah, my neighbors are pretty cool about it, but anything longer than a day is usually in my driveway. I figured the ball joints were a few hour job, but they took most of the day, that's what pissed me off so bad. Oregon in general is pretty relaxed.
Mezzanine said:
I've owned a few manual W124 and W201, and I wouldn't bother pursuing manuals in these cars either. I was pretty disappointed as a whole.
As for your question on how to proceed: you mentioned reading the MS manual. You need to really *study* the Mega Manual. It's amazingly detailed and has all the answers to your questions. I'd do fuel and spark at the same time. Plan on a full suite of sensors and triggers: crank position, cam position (the distributor might be the easy option here since I don't recall a provision for this on the M103 but I could be wrong here), MAP, TPS, Coolant temp, air temp wideband, etc. You *can* do fuel only with more crude triggers, but might as well go straight to the 60-1 or whatever the factory used on the M104 since your upgrade path already indicates the need.
Good feedback, thanks. I'll look for the mega-manual.
Sparkydog said:
In reply to Kyngfish :
I know the current "mayor" of River Grove!!!
If you hang out around here let me know. Happy to meet up for a coffee or a chat, or if you're at a local car event.
