Ownership Verified: My 1989 Mercedes 300 SEL

Jupix

Well-Known Member
Joined
Dec 13, 2007
Messages
1,579
Location
Finland
Because yesterday had shit weather, and this car can be turned from a commuter car to a classic by driving it through a carwash, I decided to take it to our annual local MB Club meetup.

DSC_0209 by Juha Kohvakka, on Flickr

While there, I got the opportunity to exchange keys with a friend for a bit, and drive the near-mint S124 300TD (OM603) series 2 visible in the picture (BRK-294). Green with cream leather and dark wood trim. It was a cool car. Interestingly, it's super easy to feel the relation between my car and his. Yet even in his words, the S-class just feels like an S-class. It does everything it can to isolate the passengers from everything that's happening outside or related to the dirty business of traveling. In contrast, the 300TD felt like a an indesctructible machine that will do it's job (hauling people and cargo) until the planet explodes. I don't think I've ever heard an engine that sounds more utilitarian and bulletproof than that OM603.

I can totally understand the OM603/606 crowd now. But, gasoline for me. :)
 

Jupix

Well-Known Member
Joined
Dec 13, 2007
Messages
1,579
Location
Finland
I think it had almost 400k on it! Couldn't really tell, apart from some very minor rust in the rear wheel arches.
 

Posambique

Well-Known Member
Joined
Jul 2, 2014
Messages
629
Location
Helsinki, Finland
Car(s)
Porsche 944 -86, BMW 323i Coupe -96
Yet even in his words, the S-class just feels like an S-class. It does everything it can to isolate the passengers from everything that's happening outside or related to the dirty business of traveling.

Nicely done making me want one... :mrgreen:
 

Jupix

Well-Known Member
Joined
Dec 13, 2007
Messages
1,579
Location
Finland
Failed inspection. Reason: leaking fuel. Would you believe it, it developed a fuel leak on the way to the inspection.

Cause? You won't believe that either:

ePWSVvV.jpg


About 3 years old fuel filter, has a hole right through it. How that even happened I don't know, but I spent my new year in my service pit taking the fuel pump package apart AGAIN. At least I could do it in the warm garage and standing up this time.

The pipe and hose connected to the fuel filter fought me again. This time I'll use copper paste or something. Oh and I'll wrap the new filter in duct tape. :lol:

Garage pic:

6IXto80.jpg


Driveway pic:

4kVCkuH.jpg


Poor SEC out there in the cold :(
 

Jupix

Well-Known Member
Joined
Dec 13, 2007
Messages
1,579
Location
Finland
Inspection passed.

Long story short I had to reuse old copper washers from the previous filter installation in order to get the new fuel filter anything close to not leaking... I bought a kit that comes with many sizes of copper washers, most importantly 12mm and 14mm washers (interior diameter). 12mm wouldn't fit the banjo fitting, 14mm was slightly loose, 13mm didn't exist and would've been closest to the originals. I don't know why the 13mm vs. 14mm matters, because the rim of the washer still fits against the banjo fitting and forms a tight compartment (theoretically) no matter the volume of air inside said space... but it leaked badly with the 14mm washers. So, there was no alternative but to reuse the old (I guess 13mm) washers...

All this trial and error took many days but finally it's done and the car is stamped (well, the papers are).

Neglected to mention one positive aspect of the inspection. Last winter I swapped the fuel injectors, but that was after the inspection. So, this time I got to see the effects on the emissions machine and also tune the mixture while I was there. So I'm getting really good emissions now for a non catalytic converter car.

Previous emissions:

CO: 2,42 %
HC: 488ppm

New emissions:

CO: 0,60 %
HC: 54ppm

Finally, a confession. This car is supposed to be a reliable and "feelgood" grocery getter but lately it's been anything but. It currently has multiple issues that are only going to get worse, and all the time it's causing me to worry instead of feelgood.
- Engine leaks a lot of oil. The only way to fix that properly would be to basically lift and rebuild or replace the engine.
- The center muffler is only patched up and it will rot again soon enough. Also it's already leaking in another place (weld in one outgoing pipe from the center muffler) but didn't fail inspection... yet.
- The engine keeps stalling in a certain scenario, which I attribute to distributor cap. The engine eats distributor caps like bread. It's possible there's supposed to be a very large rubber O-ring between the distributor cap and the distributor, but there's none on this car, and moisture is developing rapidly into the cap, which I'm guessing is causing the stalling.
- In order to eliminate lifter clatter, last year I swapped the hydraulic lifters (I guess I forgot to make a post about that). But while the engine is now completely smooth and silent when first started there's still a very loud knocking noise which appears when the engine gets to normal operating temperature. It's possible one of the 12 lifters was bad, which I intend to solve/eliminate with 2 extra lifters I bought, but it's also possible the cam or rockers are on their last legs (or some other worse problem).
- There has been a terrible drivetrain vibration on this car for the last ~year. When it first appeared I tested another set of wheels and the car was still vibrating. By manually shaking the driveshaft it was obvious that the driveshaft center support bearing must be replaced. After having the bearing and flex disc swapped, the car is still vibrating. In the spring I need to test another set of wheels again, and if the car still vibrates, the only option would be to rebalance the driveshaft (for which there are no shops or experts in this area).
- The front brakes are in need of full overhaul (discs, pads, everything). The discs are dangerously worn and the brakes are sticking. (The vibration could be attributable to this as well.)

Because of those issues, I'm seriously considering selling or parking the car in the spring, when the 560SEC is drivable again. By considering, I mean one of those things will happen for sure, but don't know which one yet.
 

Lastsoul

Well-Known Member
Joined
Jul 9, 2005
Messages
2,180
Location
Finland
Car(s)
MX5, 406 Coup?, 106 Rallye, Porsche 924, X300 Six
That's the common issue with old daily driver's. They're great cars, but they require lot of maintenance. No matter how well put together the car is, at some point comes the time for "partial" restoration. It might work reliably for much longer, but it needs work to provide the "feelgood factor" as you said.

Apart from the clatter everything sounds reasonably easy to do. If the engine is just leaking and not burning oil, changing the seals shouldn't be too big task.
 

Jupix

Well-Known Member
Joined
Dec 13, 2007
Messages
1,579
Location
Finland
- In order to eliminate lifter clatter, last year I swapped the hydraulic lifters (I guess I forgot to make a post about that). But while the engine is now completely smooth and silent when first started there's still a very loud knocking noise which appears when the engine gets to normal operating temperature. It's possible one of the 12 lifters was bad, which I intend to solve/eliminate with 2 extra lifters I bought, but it's also possible the cam or rockers are on their last legs (or some other worse problem).

Cross this one off the list...

I swapped those 2 extra lifters into cylinder #1 (which I had identified as the source of the noise with a mechanic's stetoscope). The noise is gone.

So, Motonet had sold me a defective lifter last year...

Of course even this didn't go as planned, because as I was putting the valve cover back on, I apparently just slightly nudged it and a little floppy part of the gasket at the very rear of the engine warped. When I was all done and test running the engine, it looked fully dry, but after about 5km driving the car it was painfully obvious it was spraying oil everywhere, so that the bellhousing was covered in it and some had even ended up on the exhaust manifold. It still wasn't visible since you can't get eyes between the engine and the firewall at all (the engine is so long) but by method of elimination it was obvious what the problem was. So because of my own carelessness I had to take the valve cover off once more and fix that.

The most annoying thing is the defective lifter, which in the end caused me to take the valve cover off and debug stuff like 3-4 times in the last 6 months. Just fucking annoying. The manufacturer of the defective part was Tructec http://www.trucktec.de/en/home/
 

public

Captain Slow Charging
Joined
Nov 26, 2007
Messages
12,246
Location
Causticity
Car(s)
Atomic toaster
Any red flags/checklist regarding this one? I'm not in the position to merely go pick it up, but it's priced interestingly and doesn't immediately appear to be a complete beater.
 

Jupix

Well-Known Member
Joined
Dec 13, 2007
Messages
1,579
Location
Finland
No red flags from me, looks like a relatively well preserved example.

Interior looks a bit neglected, probably worth it to look under the seat covers and check the condition of the original fabric. Also the condition of the wood is not clear from the pictures but that one is an obvious one to check anyway. Carpets are not original to the car. Mirror joystick seems to be broken.

Engine seems to be oily in the same place as mine. Upper coolant hose and neck look like haven't been changed. Passenger side of the engine bay has some accessory that I don't recognize. Distributor cap cover has been lost at some point apparently.

All the standard stuff to check for any W201/W124/W126 applies of course.
 

thomas

Grouchy Beemer Owner
STAFF MEMBER
Joined
Feb 17, 2007
Messages
6,170
Location
Freiburg - DE, or Texas when possible
Car(s)
E39 M5, '94 Cadillac Fleetwood, '21 Focus Wagon
Any red flags/checklist regarding this one? I'm not in the position to merely go pick it up, but it's priced interestingly and doesn't immediately appear to be a complete beater.

Finally you are looking into a car I can support :p
 

Jupix

Well-Known Member
Joined
Dec 13, 2007
Messages
1,579
Location
Finland
Jupix;n3361028 said:
- Engine leaks a lot of oil. The only way to fix that properly would be to basically lift and rebuild or replace the engine.
- The center muffler is only patched up and it will rot again soon enough. Also it's already leaking in another place (weld in one outgoing pipe from the center muffler) but didn't fail inspection... yet.
- The engine keeps stalling in a certain scenario, which I attribute to distributor cap. The engine eats distributor caps like bread. It's possible there's supposed to be a very large rubber O-ring between the distributor cap and the distributor, but there's none on this car, and moisture is developing rapidly into the cap, which I'm guessing is causing the stalling.
- In order to eliminate lifter clatter, last year I swapped the hydraulic lifters (I guess I forgot to make a post about that). But while the engine is now completely smooth and silent when first started there's still a very loud knocking noise which appears when the engine gets to normal operating temperature. It's possible one of the 12 lifters was bad, which I intend to solve/eliminate with 2 extra lifters I bought, but it's also possible the cam or rockers are on their last legs (or some other worse problem).
- There has been a terrible drivetrain vibration on this car for the last ~year. When it first appeared I tested another set of wheels and the car was still vibrating. By manually shaking the driveshaft it was obvious that the driveshaft center support bearing must be replaced. After having the bearing and flex disc swapped, the car is still vibrating. In the spring I need to test another set of wheels again, and if the car still vibrates, the only option would be to rebalance the driveshaft (for which there are no shops or experts in this area).
- The front brakes are in need of full overhaul (discs, pads, everything). The discs are dangerously worn and the brakes are sticking. (The vibration could be attributable to this as well.)

Because of those issues, I'm seriously considering selling or parking the car in the spring, when the 560SEC is drivable again. By considering, I mean one of those things will happen for sure, but don't know which one yet.

So, to go back to that list, I did end up driving the car over the summer (or rather, not driving any car much). Mostly because of laziness.

Every once in a while I had something fixed on the 300:
- Front brake discs & pads in February
- Engine oil leak eliminated (or reduced, hard to say) September (was not a proper fix; rather the leak from the timing cover was just patched up; this is typical for the M103 engine)
- Center muffler (factory resonator) deleted in early December, it was rotten in 2 places (exit pipes & top of the muffler).

Engine thermostat was also changed because with the old one the engine temperature tended to rise slowly and stay below 80C even during extended driving. As a side effect the blower wouldn't blow as warm into the cabin as it should. With the new thermostat it gets to normal 85C quite quickly which is how it should be.

I've also spent another approx. 1000€ trying to have the vibration issue eliminated, but it's not. The shop changed propshaft mount, a driveshaft, some more rubber bushings, the diff oil, and rebalanced the wheels (even though I'd tried two sets of wheels, which I also told them beforehand). As a next step I'm refurbishing the OEM wheels and buying new summer tires on them, to eliminate the possibility of me having two sets of tires with flat spots or something. Then, probably taking it into another shop again (the third one) - this time probably the dealership shop.

Anyway, at least it passed inspection the day before yesterday. Since the previous inspection, I'd driven the car approx. 3500km. (As a point of comparison, I drove the 560SEC approx. 2300km.)
 
Top