2005-2006 E320 CDI Buyers Guide, Common Problems, & Roll Call - Page 15 - PeachParts Mercedes-Benz Forum

TylerH860 · #1 03-15-2015, 10:58 PM

Time for a dedicated thread given all the recent purchases and bring some Google traffic our way. This thread will be continuously edited so feel free to contribute and I will add to the post. Also, let's have a CDI owners roll call. List your current miles along with non-maintenance related repairs. Date of purchase and price (optional) as well. This will help greatly with the buyers guide.

For the perspective buyer and the CDI unwashed, hurry up and buy one. You will not find a more satisfying car. It's the best diesel passenger car you can buy right now for under 20k. You won't be associated with the jerks that own BMWs should you purchase a 335d. With Volkswagen you have to worry about engines, transmissions, injector pumps, rattles, interior bits breaking off in your hands... basically everything. The CDI feels like it has enough torque to stop the rotation of the earth should you romp on it. It also rolls some serious coal, a very satisfying belch of soot out the back while you're hitting that 6 second 0-60. At normal highway speeds, over 40MPG is widely reported along with 700 mile range on a single tank. If you're old school, you'll like that it has an iron block inline 6 engine, and the old 722.6 transmission known for the same durability as Thor's hammer. If you're up with the times, it has all the tech you would ever want. It's also a pretty car. The design is not polarizing or ostentatious. Just a stately car that blends with whatever level of society you consider yourself.

It seems something is in the water recently and people are dumping these CDIs for peanuts. Nice cars with under 200k and good service history are popping up everywhere... The realistic price range seems to be $7000-$17000 depending on mileage. Just a few years ago, prices were nearly double. It's safe to say they have bottomed out. Considering old W123s in similar condition and mileage can bring the same money, and you're dealing with maintaining a 30+ year old slow vehicle that gets 25 MPG downhill, the CDI just makes sense. With so many available, you can be picky. No reason to buy third or fourth hand from cousin Vinny off south Broadway. Just like with 80's W123 300Ds when you were shopping for them 10 years ago, there's owners that fixed things in a timely manner and decided to get something new, and there's owners who let issues pile up and play pass the turd when it becomes too much.

Unlike when you were shopping for a W123, every dealer repair should be stored in the computer. All original warranty work is accessible to all Mercedes dealers. Anything after that is kept with the dealer that performed the work, and reported on the vehicle history report. For the most part, the days are gone of phone book thick paper maintenance records or run away. A little time at the dealer or $30 for a history report can tell you alot.

Speaking of dealers, the car business has completely changed. New car dealers are hanging on to every used car trade-in possible. The only cars second hand dealers can get their hands on are the reject trade ins. These dealers usually do not have the resources or the interest to recondition these cars to the level of the keepers at the new car dealers. As a former used car slimer myself it's hard for me to say, but avoid used car dealers. You will see higher asking prices with new car dealers, but big haggling is their style.

I purchased my CDI from Plaza Mercedes outside of St. Louis. It was a 1 owner new car trade in serviced nowhere but their dealership. With just under 200k, a few years ago it would have immediately tossed to the auction only because of the high mileage. I would guess they gave him around $6500 in trade, and spent $500 in detailing, services, and a few minor repairs. It was on their lot for $9995. I offered $8000 out the door and they accepted quickly without much dance. It was a full red carpet transaction just like the other guy spending $100k on new S class was getting. They even offered me their undercoating and paint finish protection with door ding insurance for an additional $7000. Absolutely true story. Sure there's exceptions to everything and plenty of private party sellers with good cars, but you'll find the most good cars at new car dealers. Just ignore their silly asking prices.

Unlike W123 ownership, these cars can't be fixed with just a few bents wrenches, a hammer, and manly forearms. Other than basic diagnostics and repairs, you will need some form of way to interact with the car's computer. Whether you buy a used or Chinese copy of Mercedes Star SDS system, or some other advanced diagnostic computer with the right software to interact, if you plan on doing much DIY you will need these. While they cost at least a grand unless you find some bargain, it makes diagnostics much easier. Gone are the days of guessing. These cars will know exactly what's wrong with them and the right computer will tell you step by step how to fix them. Every fault is stored; I wouldn't be surprised if the car remembers the last time you farted in the seats. This does get annoying, as many things require the computer to reset the fault or reprogram the part. For example, if you were to evacuate and recharge your AC system, you have to reset the computer in order for your AC to work. It does not want to switch on with any active fault. If you don't want to work on it yourself, I would say the running costs would be about the same as maintaining a 30+ year old Mercedes. Figure spending a few grand a year in upkeep. Some years better, some worse.

There's lots of conjecture on proper service intervals. Mercedes intervals it at 13,000 miles and that's probably fine with how advanced synthetic oil is now. You could do half those intervals, it certainly wouldn't hurt. Sludge does not seem to be a problem in this engine compared to other Mercedes gasoline engines. Transmissions are "sealed for life" and that should certainly be ignored. I wouldn't want more than 100k on transmission fluid. Same goes for other fluids. Even good cars serviced regularly with good sellers will have hidden problems, so its worth knowing the common problems these cars have. Most non MB dealers wouldn't pull the engine cover to look for black death around the injectors, and could easily miss worn ball joints or one of hundreds of electronic doohickeys that can break. So its good to know the common problems which is listed below.

Black Death (injector seal leakage): Sounds a lot worse than it is, but is something to keep an eye on. Underneath the useless decorative engine cover can hide a nasty surprise. During your first inspection under the hood, warnings signs for this would be a burning oil smell or an extra hissing tick noise outside the normal diesel clatter. You will still want to take the engine cover off and examine the injectors. Next time my engine cover is off I think I'll write an inspirational message in silver Sharpie. Like "Once more unto the breach".

On higher mileage cars its almost certain you will find a hint of it around the injectors. No big deal. You can use this as a factor in your negotiations as this is something that will need to be monitored and eventually addressed. Wait too long this build up can ruin your injectors and wiring. Also, I am told the longer you let it build up, the harder it is to remove the injectors and good metal surface to reseal properly. Quality injectors will set you back $450-$600 each. Seals not very much. Some have reported VW injector seals are superior to the Mercedes supplied ones.

Video of an extreme case of "Black Death"... or when you eat too much Taco Bell
https://www.youtube.com/watch?v=im42MsPJlqs

Transmission Conductor Plate: A common problem is your transmission to get "stuck" in fourth gear after a highway run, requiring you to shut the vehicle off. This electronic unit inside the transmission can cause plenty of issues. $1000 fix at the dealer. You will need the SDS tool to reset the transmission control module otherwise the fault will remain.

Battery Messages: The W211 chassis has 2 batteries. The redundancy is due to the electronic brake (SBC) system. There is one large battery in the trunk and another small motorcycle sized under the hood, below the cabin air filter. A black message reading "low battery, conventional functions unavailable" light usually point to the main (rear) battery. A red message saying "low battery visit workshop" points towards the small auxiliary battery in the front. Early in the W211 production, there were issues with alternators and battery control modules causing errant warnings and other issues, but these seem rare by 2005.

SBC braking system (Brake Messages): I think of Jeremy Clarkson's car reviews when he gushes on about the fantastic machine he's driving, then starts to notice the annoyances. If this car has a BUT, its this system. Mercedes abandoned SBC brakes starting in 2007 and is the likely cause of their reliability ratings going down the toilet during those years. Given Mercedes successfully pioneered throttle by wire systems which gave us the annoying nanny of traction control, along with inventing ABS brakes, you can understand their zeal running amok when they created this brake by wire system. Lot's of little idiosyncrasies. Like if you're doing your own brake pads and your wife decides to open the vehicle's door to grab her purse, the brakes engage and chop your fingers off.

Service records are very important with the SBC system as it tells you if the SBC pump has been replaced and if all the campaigns have been done. If you get a "service brake, visit workshop" message, the code will usually read that your SBC pump is worn out, but wait! After replacing tons of good pumps because the software said they were worn out, their final fix was to reprogram the "replace the pump" timer to an unspecified time well beyond their warranty. (So nice of them). Many cars never got this "reprogramming" and will surprise you with this message. There's lots of conjecture about the reliability of this system since, but if there's no records of the pump being replaced I would keep that in the back of my mind, as its a spendy repair ($2000). They extended the warranty on the SBC system to 10 years and unlimited miles, expired on alot of CDIs by now.

Lower Ball Joints: If you hear a creaking noise over bumps or notice uneven tire wear, chances are its the lower ball joints. If you're looking at a car with over 100k on the originals, it's almost certain this needs to be done. This is not a pricey repair.

Electrical: This is already turning into a book and I don't want to turn it into an encyclopedia talking about all little electronic things that break, but know there's alot of them. It's usually rare and random when they break. Some highlights include the car thinking someone is sitting in the passenger seat and will annoyingly chime for your phantom passenger to buckle up. This requires a SDS tool reprogramming of the seat with a weighted Mercedes butt simulator tool. They literally have something that simulates a butt in the seat to perform this task. If the car you are looking at has keyless go, (unlocks and starts car by proximity sensor in your key which never leaves your pocket) do not plan on it working. Also another amusing throwback repair is the electric monovalve for the climate control system. 40 years later they still design a monovalve that gets stuck on hot or cold, like they are paying tribute to issues past. Like I said, these issues are usually rare and easy enough to fix, unless it's keyless go. Maybe label the start/stop button on the shiftier knob "eject passenger" for gags?

Ejecto Seato Cuz!

Like I said, any additions welcome, and please star the roll call. I will with the next post.