The bug list

With the Airstream parked and no trips in sight for a while, I’ve turned my attention to the 1984 Mercedes 300D for a while. I bought this car last summer and wrote about it then.  It was not perfect when I bought it but I resolved that if it turned out to be a fun car and behaved itself (not immediately chewing up a bunch of parts, like a new puppy) I would be willing to invest a little into it in order to keep it roadworthy for a long time.

The car has so far passed that threshold.  It’s a solid, safe, reliable set of wheels and I like driving it.  But even though it is completely drivable, it still has a lot of small issues to resolve. So I made a “bug list” of things that needed addressing and started prioritizing the work, with an eye toward vehicle improvement without personal bankruptcy.

Earlier this week, the list looked like this:

— transmission shifts abruptly when cold

— leak in vacuum door lock system (leaks when doors are locked, not when unlocked)

— center dash vents don’t actuate (no air flow)

— windshield rainwater leaks (needs new windshield gasket)

— instrument cluster lights are very dim

— odometer only turns on cold days

— slightly squeaking AC belt

— rear windows shudder going up and down

— sagging drivers seat spring

— intermittent low fuel light

— electric passenger vanity mirror doesn’t adjust

— chipped wood around climate control

— cruise control does not work

— wiper motor sometimes activates on startup

— tear in driver’s seat

Some of these things are pretty clearly unimportant, while others are a major nuisance. The lack of air from the center vents, for example, means that the car doesn’t have enough air conditioning to be usable in the Tucson summers.  But the trick is to prioritize the jobs in a way that makes the most sense, and that means fixing the problems that might compromise safety first.  Not only that, but before I start tweaking the little things it would be nice to know that the transmission shift issue doesn’t mean fatally-expensive repair is looming in the near future.

I’ve had the car over to a couple of different shops in the Tucson area for minor repairs, but I wanted to get an opinion from another highly respected Mercedes specialist up in Phoenix before launching into the project.  This made the perfect excuse for a long-awaited roadtrip in the 300D, about a hundred miles each way between Tucson and Phoenix.  Alex came along for the ride, since he had an old Mercedes years ago and wanted to relive the experience.


The guys at the shop were extremely complimentary about the car. They don’t see a lot of the old W123’s (which is the chassis type of the 300D) in good condition anymore.  The prior owners of this car really took good care of it and made sure that it was serviced only by people who knew Mercedes.  As a result, there was almost nothing botched by prior shops to undo and repair.  They poked around every subsystem of the car and explained things as they went.  I’m always impressed with the quality of engineering that went into these old cars.  Every part is beautifully designed for function and serviceability in a way that helps justify its original (new) purchase price of over $30,000 in 1984.

The point of the visit was mostly to evaluate the car and come up with costs and priorities.  Alex and I left the car for a few hours while we did other things, and when we came back the odometer had been removed, disassembled, repaired and re-installed.  They also fixed a few other small items, but unfortunately the list grew more than it shrank.  Now added to the bug list:

— broken air filter lower bracket  (part was not available immediately, or we would have replaced it on the spot)

— shock absorbers all around for better ride (mine are apparently original to the car)

— right front ball joint is a little loose

— upper control arm bushings are worn

The transmission shift issue was checked and confirmed to be “just the way these cars are.”  It shifts pretty smoothly once warmed up. Since this is the third Mercedes specialist to give me this opinion, I’m going to accept it and drop the transmission from the bug list.


The guys also ragged on the Goodyear “Weatherhandler” whitewall tires that the prior owner installed.  A more typical choice for this car would be Michelin or Pirelli. I have had little respect for the tires myself, having already experienced a few moments of adverse handling in light rain, but they will probably last for many more miles so I’m stuck with them for a while.

No other problems were noted, so the good news is that the car is perfectly safe to enjoy and gradually improve. We got a list of tips and parts sources to guide the ongoing process, along with estimated costs for each repair.

With that, we jumped on I-10 to escape Phoenix before rush hour traffic turned the highway into a slow-motion lava flow.   We had 100 miles ahead of us, which goes pretty quickly when you get to the open road with a speed limit of 75 MPH.  The car seemed happy to stretch out a bit after all the city driving I’ve been doing, and for the next 90 minutes Alex and I listened to the purr of the old diesel, and I reflected on the simple joy of once again having an odometer that actually turns.

Every little repair like the odometer puts the car closer to completeness.  When I bought it, it was a fine machine that had been kept in good operating condition but the “little things” left unattended were starting to pile up.   It seemed to be teetering between well-loved and slightly neglected.    Gradually I’m pushing it toward the right end of that spectrum.  It will never be perfect or qualify as a “show car,” but it is earning my respect enough to put some money and effort into keeping it on the road.


  1. says


    Welcome to the real world where one has an intimate relationship with the older cars. LOL. Been doing that for 35 years and find they will never achieve completeness mechanically but they completely achieve fulfillment. As good (relative term) as the new MB’s are, they will never equal your old MB. Apples and oranges.

    Thanks for keeping us up on your classic car! Lucky dog.

  2. Brett says


    Could the dash vents and the lack of air flow being that the blend door is vacuum actuated and the vacuum leak that makes the doors not work is related?


  3. says

    Brett: that was one of my questions too, but the vacuum leak is only in the “lock” side of the door system. In other words, if the car is left unlocked it retains vacuum indefinitely (at least overnight). So while the car is running and/or doors are unlocked there is plenty of vacuum to actuate the center vents.

    It’s a common problem with these cars for the vacuum “pod” that operates the center vents to fail. Unfortunately, the fix involves pulling the dashboard out. I’ll have to get this one done before A/C season arrives.

  4. Brett says

    Sounds like you have a handle on it.. I am doing much the same thing with my 1992 Range Rover, fix things slowly working towards 90% perfect.. You can only make it perfect if you have a bottomless bank account.. And then it will only stay that way until something else breaks.

  5. insightout says

    Will insightout have to forever wear the financial mantle of shame each time the Man-in-the-Maze has to write a hefty repair check for his teutonic obsession ?

    I accept responsibility for introducing a Vermont virgin to pole dancing with the students of Stuttgart, however, no apology will be forthcoming, as I have my own gremlin under the hood of a 1965 220SE.

    And Brett, if you get your Range Rover to 90%, that would be 30% better than when it left the factory floor in Solihull, England, Having owned a 1988, the lousiest piece of cr#p ever (aside from the Yugo). The first, last, and only Brit car to inhabit our stable, I can offer sincere sympathy in your continued grieving.

  6. Brett says


    I appreciate and completely understand the love/hate relationship. I too had a 1988 model and while it was not a bad truck, it passed everything EXCEPT a fuel station. Alas I sold it before it actually turned on my wallet, thus leaving me with fond memories… This explains why once again I have a Rover. You now know why I drink.

  7. Tom says

    Life is too short for bad tires. I’d put money there before addressing some of the other stuff on the bug list.

    Part of the joy of older cars is having relatively cheap tires. I’m buying a used Miata shortly – it’s great choosing from tires that are $65 each! Heck, four tires for the 300D are probably cheaper than one tire for the GL! :-)

  8. says

    Tom: You’re right. One run-flat tire for the GL320 is more than all four for the 300D. Horrifying. Another reason to like the old car for routine trips …

  9. says

    Rich, having had some experience with my ’81 380SL, with several of the same problems you’re discussing, I estimate that the small investment of the original $30,000 price tag toward those repairs will allay all of your automotive worries.

    Yeah, even with the wrinkles and scars delivered at time’s hands, and labor costs be damned, those old Benzes still have a lovely feeling when they are cruising…