MBDiesel.net - An Owner's Journey

Hey, how about 8 months between updates, huh?

Hopefully this will make up for it a little bit - valve stem seal replacement on the 300TD!

Things have been real busy since the last update. In a brief run-down, I injured my back, seriously injured an eye, and went back to school. Then Donna and I got married, I got a part-time job to go along with school, and what little time I used to have evaporated.

I know many of you out there have been begging for more frequent updates, and I'll still be doing what I can, when I can. But unfortunately, the tone of most repairs these days is of the "Oh crap, get this fixed PRONTO!" variety instead of the "Oh, won't this be fun to take pictures of and post on the internet?" sort that I prefer. Quite obviously, cameras usually aren't around for the former as much as they are the latter.

Also, as of about a month ago, we said goodbye to our 1980 300SD. She's living out the remainder of her life with a friend of ours - may her miles continue to be reliable and long-lived!

Best to everyone out there, and enjoy the holidays!

I've strayed, dear readers. I've strayed, and I've been neglectful. I haven't been paying enough attention to the site, even though there have been things going on around here with the cars.

For instance, I had to swap the transmission in the 300TD because the bearing noise in it was getting just a little scary, and it was crossing the threshold of "liability to drive". We need the car to be our reliable trip transportation, as well as schlepping me back and forth to work, so the excessive bearing noise from the transmission had to be addressed. I swapped in the low-mileage unit from the 280S, put a shop spare into that car, and continued along my merry way.

Just kidding. I tore into that old gearbox to find out what the trouble was - the noise was coming from the rear bearing on the countershaft - spalled bearings, missing material in the race, it was toast. So then I put it all back together. And then took it apart again a few more times. And put it back together. Rinse, lather, repeat. And now that I've purchased some additional tools, I'm strongly considering rebuilding that box.

But this doesn't begin to explain my dalliance with another motorized vehicle manufacturer. I've kept this secret for quite a while, but now it must come forth - I own two BMWs in addition to our collection of Mercedes.

Blasphemous, I know. And even worse, this update is to show a write-up of some maintenance work I performed today. Go here for the rest.

Just finished replacing the vacuum pump on the 240D today.

Yesterday, after completing my first oil change with my new MityVac topsider, we started the car up to check for leaks, etc. I kept hearing a faint sound coming from the front of the motor towards the driver's side - kind of like tink ta-tink tank. Very random and staccato, no real rhythm to it.

I really wish I had a true mechanic's stethoscope, but in a pinch, an 18" quarter-inch drive extension will do the job adequately.

I first checked out the power steering pump. Nope, not it. I was still hearing the noise in one ear, but not the ear close to the improvised stethoscope. Then, I checked the vacuum pump.

Bingo. Noise in both ears.

Then I checked around that area of the block, and was back to nothing. Nothing on the injection pump side, either. Back to the vacuum pump, and there it was. Tink ta-tink tank. Subtle, yet easily heard with the hood up over the noise of the motor. Then again, our 240D is considerably more quiet than your typical 300kmi clatterbox - she should be, as the motor only has 34k on it!

So, we parked the car and this morning I ordered a replacement vacuum pump. We put it in this afternoon, and everything is back to normal.

Upon removal, the bearings on the rocker arm showed signs of excessive wear, and the roller between them had severe lateral play. She wasn't long for this world.

When I have some free time this weekend, I intend to disassemble the old pump and take some pictures. Been a while since we've had a photo update of some kind around here!

It's been a busy past couple of weeks at the shop. Today was a little slow, so Mathieu and I got to wrench on our own cars for some much-needed massaging, love, and attention.

The 240D had been exhibiting some very weird noises from the front end recently. It sounded like a groaning noise from inside the cabin when the steering wheel was first turned - a quick check of the power steering fluid level revealed that the reservoir was a little low.

However, after resolving the fluid level, the noise was still present, though a little muted - I'd obviously addressed part of the issue, but had not completely resolved it.

A little more troubleshooting pin-pointed the noise to the left front corner of the car - and it almost sounded like the spring itself was resonating. That's bad news, because broken springs on these cars are very dangerous.

I drove the car to the shop one day, and talked over the issue and symptoms with Mathieu. We pulled the car in and cautiously checked the spring - everything seemed fine there. Mathieu then used a mechanic's stethoscope and accurately diagnosed the noisemaker - the ball joint in the upper control arm.

The control arms were manufactured by TRW, and have approximately 5 years and 50k miles on them. Today, we replaced them with Febi/Bilstein arms, as well as installed Bilstein Heavy Duty shocks in the rear of the car. The ball joints in the old upper control arms were immovable by hand - placing the joint in the bench vise and moving the arm around, we were able to feel that the joints were all but seized.

Also visible on the UCAs in the area where the torsion arm bushings seat was a lot of wear in the metal - very bright, very shiny, very smooth. Mathieu said he normally sees this in cars with 150k on the UCAs, not 50k.

I guess Donna will need a little talking-to about her driving habits again.

We also observed that the outer boot on the right rear halfshaft is torn, so it looks like I'll be hunting for halfshafts again soon.

Things aren't looking too well for those custom alternators we installed in the 240D and 300TD last summer. The voltage regulator in the 240D's alt bought the farm this week - 12.3 volts output at any RPM range. When Donna drives from here to Conyers and back with the headlights on, she would end up with a dead battery greeting her the next day. I've swapped in the voltage regulator from the 300SD's alternator after shuffling Donna off to work in the wagon, and voltages are back to ~13.8 at fast idle, ~13.4 at normal idle, and seeing low 14s with off-idle speeds. Much better.

On the wagon, it sounds like the bearings themselves are wearing out. We'll be getting a call this week into Sleepy Hollow, the rebuilder who provided the units, and we'll see where to go from there. I don't expect there to be any problems per se, I just hate duplicating work. I hate it almost as much as borrowing parts from cars, thereby making them inoperative, just to keep the daily drivers running.

Speaking of the wagon, it had it's first 2 road trips since the manual transmission conversion - we've been seeing fuel economy ranging from 25-27mpg, versus the 21-22 we'd normally see with the automatic. We hit 27 and 29 once with the auto - the 27 required driving the Natchez trace at 55mph (my mind can't handle doing that very well), and the 29 was when the wagon was loaded to the gills with about 1100 pounds of tools, engines, and various other things on a trip back from Florida with no power steering. Weird car, that one - I have no idea why it always gets better fuel economy loaded up with 4 people and their stuff for a weekend road trip than it did with just one or two people doing the same thing.

Carb kits for the 220 should arrive this week! There will be pictures!!

It only took 16 months, but I actually managed to photograph me doing something with the 280S. Seriously!

You can find it here.

I have the photos for the 300TD manual transmission conversion hosted and posted. You can go here to check out the write-up.

Donna and I had a lot of fun yesterday. Go here to see more.

In other news, we resurrected the 280S yesterday as well. One fuel pump, one water pump, and a coolant flush later and my beloved rust bucket was back on the road! Sorry, no camera work on this one. Neither were particularly bad jobs, and I took my time. Replacing that Pierburg fuel pump transformed the car - granted, the last time I drove it, it wasn't pumping much fuel at all, and wouldn't move unless I was bump-starting the car back into the shop parking lot... ;-)

Been a while since a good update.

The 220 is giving me fits right now, what with it's whole not-starting thing. It's getting air, the fuel pump works like a champ, and I've got spark (at least to the distributor), what I'm lacking is better weather to continue to troubleshoot the issue. My bet is on the cold start function of the carb constantly sending a slug of gas into the intake, or a post-dist cap spark issue. If the weather is nice this weekend, and I'm over my cold, I'll see if I can fool around with that old Stromberg 175 and see what's up.

On the plus side, I did give the car a fuse service on Wednesday. Whoopee!

Only 1 tight valve - intake on cylinder 1. Everything else was good. I'll probably need to adjust intakes on 3 and 4 next time I check them.