W211 CAN Bus problems
 

Edit to add: central gateway (search optimization)

I have had my W211 for about a year and a half and it has been great so far. Until it started dying on my son for no apparent reason earlier this summer.

Back in June my son was driving the car from Clemson to Charleston, on his way to his girlfriends, late in the evening of course, and he calls me in a panic. Multiple warning lights and messages (ABS light and loss of ABS/ESP message was one I remember), dome light flashing on and off, a/c blowing hot and cold, etc. He gets the 'red battery' symbol so I am thinking alternator. He pulls off the highway and I get him towed back to Columbia.

Pull diagnostics with my Xentry and nearly every module in the car has multiple stored faults for CAN failure to talk to other modules in the car. Both power train and body buses have problems. And messages about CAN bus shorted and CAN bus shutdown. 8 pages of printout. Of course everything is a lower case f which means fault came and went and is not present now, (capital F means fault is active right now).

So I dig into the CAN bus distributors and can't find any corrosion or loose connectors. But I did find under the right dash that the CAN bundle was laying against the aluminum foot plate that protects the electronics boxes in the footwell. There was a slight chafe on one of the CAN wires. So I de-pinned that connector, heat shrunk the chafed wire, and put back together. And zip tied the distributor and bundle in a better location below the dash where it won't hit that aluminum plate anymore.

Before I purchased the car (private sale in spring of 2018) the previous owner had an indy shop replace the oil cooler seals. Well they did not replace the o-rings and gaskets on the intake tubing in the front of the engine. This caused soot to blow all over everything up front and the alternator was caked in black crud. I thought well I better go ahead and replace this thing anyway, and put all new gaskets in the intake tract, and clean this mess up, before giving the car back to my son.

So after getting the car back together it drove fine for about a month until my son decided to go visit his girlfriend again. This time he got there ok and was getting ready to head back home, and only this time it refused to crank. No spin at all. Another tow back to the house.

Pulled codes again, same sort of errors, not an identical list but many similar as the first time. And of course the car started fine once it got back to the house. Tow truck driver confirmed he could not start it at the far end, and in fact could not get it out of P, and had to use the emergency release to get it up on the flatbed.

Spoke to my friendly service advisor at the dealer who used to be a tech and he's real good about letting me bounce ideas off him. He said check for water intrusion and the worst 2 places on a W211 are the rear SAM in the trunk and the ZGW under the dash. He said the trunk water comes from bad trunk gasket (duh) and the ZGW caused by plugged sunroof drains leaking water down the a-pillar into the wiring behind the dash. The ZGW faces up under the knee cover and the wiring harness wicks water drips down into the connectors.

First went to the trunk and pulled the left liner to see if the rear SAM was getting wet from a trunk leak. Everything was completely bone dry with zero evidence of any kind of wet back there. Pulled the plug with the body CAN wires and everything looked pristine.

Next I dropped the knee cover on the drivers side to reveal the ZGW. It is a little gray box about the size of a deck of cards. When I pulled the plugs out I saw evidence of corrosion. I popped the module off the knee cover and opened it up. Sure enough there was corrosion inside on the plug pins going into the circuit board, mostly on pins 7 and 8 and 9 and 10. Pins 7 and 8 are the engine CAN and 9 and 10 are the body CAN. Lots of green grunge growing between the pins.

I got some isopropyl alcohol (91%), wooden toothpicks, and cotton swabs and was able to clean up all the corrosion. Flushed everything out really well with alcohol and then let it dry overnight. I put the module back together and put it back in and the car started right up.

Took the car out and ran several errands so went through about 6 or 7 start/stop cycles and everything running good.

Tomorrow I will pull the dash area apart and verify the source of the water leak.

Just wanted to pass this along, if you have a W211 that is having CAN bus issues check the ZGW module.

As I read your post I was wanting to ask if heavy rain was involved. I have had similar problems after a car wash or heavy rain. My water problems

Caig offers excellent contact cleanses and conditioners

A day of drying has cured my problems. Thanks for the excellent information

Nice write up....thanks for the pioneering leg work.

That's excellent diagnostic work, well done and I hope the problem is resolved.

Please refresh my memory, as I recall the central gateway module is responsible for pulling diagnostic information from all the assorted ECM's in the vehicle and making the resultant data available for ODBII access? I think it also is responsible as a access point and protocol for passing data from one CAN to another correct?

It seems a little strange and disturbing to see how disrupting the CAN architecture on modern MB's can apparently totally disable the car. I realize that data transfer and sharing is essential for many/most of the sub systems in play but it just seems like the hardware and software of the systems should be able to fail in less catastrophic way if data communication is disrupted. I think the engineering term is something like 'graceful degradation' or something like that?

It's been a few years now but I remember someone that had a DCM in a W210 fail and it took down the entire interior CAN network. Seems like if a central gateway has issues it can disable every CAN in the car?

There are 4 modules on a W211 that connect the engine and body CAN buses together. The ZGW is the primary connection and the only one that can pass packets between the two networks. There are 3 other modules have double connection to the CAN buses, so they can read and write each bus, but cannot bridge data between them. I reverse engineered the wiring diagrams and made a one page tree diagram of the networking in a W211 and then found the actual diagram in the Star Finder utility. But now I am on the road and can’t recall what they are (maybe instrument cluster, key switch, and front SAM?)

CAN is meant to be able to run in a degraded mode if you short or open one of the two lines. The data is passed using differential signaling, which is a fancy way of saying that each line has a copy of the data, one is positive biased and the other is negative biased. This results in high EMI tolerance as any induced voltage will affect both lines equally.

But if you dead short the CAN then you are pretty much out of luck. This is what finally happened at the second failure, the green grunge built up to the point where it completely shut down the network.

I agree that it is crazy that a short in the CAN bus will pretty much shut things down.

W210 has both CAN buses and they meet at the key switch instead of a gateway module. The W211 (and other models of that same era) introduced the ZGW as a formal bridge between the two systems and also this is where the vehicle coding is held. I also think this is where they store the fault data on CAN bus health. There is a huge Freescale processor chip in this little tiny package.

They did a couple dumb things on the design in my opinion however. First I would have put the 2 buses on different connector plugs for isolation (and at least not on adjacent pins!). Also I would have located this module differently. Having it face up with the wire bundle leading into it from above is just asking for trouble with wicking water leaks into the connector. Especially under the dash where leaks can happen from the sunroof or windshield.

I didn’t get a chance to look for a source of the water leak this weekend but will try again next weekend. At least it’s parked out of the weather at the airport now.

I remember that the CAN bridge point was the ignition switch in the W210 chassis, always seemed like a strange interface point but I guess there must have been some reason to locate it there.

Agree totally on the placement of the ZGW model and the location of the CAN pins on the connector. Is there enough room on the wiring harness to re-orient the module with the connector facing down?

All CAN modules should have a fail-safe backup mode that implements a plan if all communications are lost with the CAN. At the very least that plan should include an error message in the module that clearly states that CAN communications have ben totally disrupted and a fail-safe mode was entered. I guess you can kind infer this when every module in the car issues 'the-sky-is-falling' general error messages but this kind of response kind leads me to believe that the software people never considered the possibility of this kind of failure.

Whenever I see something like this I keep thinking about how Elon and Tesla are going to deal with these kinds of issues in their 100% self driving cars that will be on the road in the millions by the end of 2020. It seems like an incredibly difficult hardware/network/software problem. Multiple redundant networks would be a good starting point I'd guess.

There are silly things on nearly all vehicles, Benz provides an isolating connector - some manufacturers dont like to spend that 2 dollars. So you get to fight with entire jumbo connectors which have the terminating pieces.

And its really irritating when they make one module the gateway too (e.g. some mazda use TCU as gateway to the slower body bus)

I noticed another clue:

For about the last 6 months, whenever I engaged the cruise control, the 'halo' around the speedometer would be intermittent. I chalked this up to the LCD going bad in the cluster.

Well ever since I cleaned the contacts in the CGW, the halo has been steady whenever the cruise is engaged.

Not 100% sure if this is a definite correlation but if you are getting this symptom on your W211 I would check your CGW to make sure it's not getting funk between the pins. This needs a T25 to take the lower cover under the drivers side dash down (3 screws).

I would recommend disconnecting the battery first before unplugging the CGW as it sets a ton of events in the system.

Still haven't gotten a chance to look for the water leak but it's been parked under cover since I discovered the problem.

Got some time to look at the car this weekend.

First tried gently pouring water into the sunroof trough at all 4 corners, the water flowed easily out to each wheel well with no puddling whatsoever. (Car sitting level).

Next I parked it engine downhill, and poured more water in the trough at the front. Still draining correctly up front.

Took the a-pillar cover off and it appears the drain tube is running through the internal part of the a-pillar (not visible from what you see with the cover removed, the only thing you see is the air bag squib).

Took out the speedometer cluster and felt around back there and could not detect any wetness.

Closed everything up and took it to the automatic car wash. Pulled the lower dash cover immediately afterward, and everything was completely bone dry.

Anyone have any clue how the water could have been migrating down the harness?

Maybe some condensation from the air conditioning system.

When I have been traveling on a long road trip with heavy rain forecast I have taped over the vents in the hood (about 5 or 6 inches from the windshield) and not had any problems. Not certain if that is the area you were referring to as the "trough".

I have had all the warning lights come on after washing the car and figured water got in from the hood vents. I could be wrong.

Good luck and thanks for the updates.

So the fun continues with this car.

On Wednesday I get a call from my son who informs me the red battery is showing on the display. It's afternoon time so he's heading home from his college intern job (about 30 miles one way). I am on I-90 heading west from Quincy to Seattle WA going over the Snoqualmie pass...

He pulls off the interstate at the exit where he lives, and limps into a gas station, and calls me. The car's system are collapsing, no A/C, warnings up and down, transmission stuck in 2nd gear, no acceleration.

I tell him to pull up the system voltage (3x reset button with mph showing and key in 1st position). 9.something volts.:eek:

How long has that light been on? Since this morning when I got into it to go to work.:mad:

Car cranks but it collapses the voltage too much so it bogs down and dies.

He gets it jumped and limps it home. Able to get a ride with one of his room mates (who all work at the same place...) Thursday and Friday.

So yesterday I gather up every tool I can think of and go the 2 hours up to Greenville. Put the meter on the battery, it had self regenerated to the low 11 V. But as soon as I hit the starter it was rrrrp rrrp rr nothing. Jump started the car with my car and got it running again. When I pulled off the jumper cables voltage crashed down to the low 10s. No alternator output confirmed.

Pull the alternator and take it to the local NAPA. They gave me another over the counter.

After 2 hours of disassembly and 2 hours of reassembly got everything back together. In the mean time I had disconnected the battery from the car and threw a 10 A charger on it. By the time we were ready to try to start it, the voltage was back in the low 12s.


Car fired right up and had a ton of codes. Unfortunately the serial cable for my Xentry multiplexer had failed so I had one on order from eBay coming from Gungdong Province on the slow boat not expected until later this month.

So I ordered an iCarsoft II so I would at least have something to take with me to troubleshoot. I wasn't able to pull any codes because the car voltage so low it would not let the iCarsoft stay up.

So once I got the alternator in there were a ton of codes for low voltage. Got all those cleared and drove the car back to Columbia (I left him my E350 again, he's driven it more than I have since I bought it in April...) with one eye on the system voltage display. Did fine, never got below 14.xx V the whole way.

When I got home the package from China had arrived. I hooked up Xentry and pulled codes and found the code for LIN bus failure to communicate with the alternator, current and stored. Cleared it and it came right back.

About to go out and double check I plugged in the connector but I suspect something else is up.

Anyone know more about the behavior when the LIN bus is lost to the alternator, does it go into some sort of default mode where it still charges but does not communicate?

I suspect I got another lemon from NAPA with a bad LIN bus communication chip this time...yay I get to pull the alternator on the car again.

So the LIN bus plug was connected. The LIN wire has approx. 8 V dc on it with the switch in run position but engine not running. That tells me there is continuity to the rest of the system.

There are three nodes on the LIN bus, the engine controller N3/9 pin 88 (the master) and two slaves, N14/3 pin 12 (the glow plug relay), and G2 pin 1 (the alternator voltage regulator). The wire is tapped at Z9 which is just below the connector for the glow plug relay down in the harness. So the first wire segment runs from N3/9 to Z9, the second segment from Z9 to N14/3, and the third segment from Z9 down to the alternator.

Since I am getting 8 V at the alternator connector (with it disconnected from the alternator), and the glow plug relay is working (it's preglowing properly - cold started fine this morning, and no other codes exist for glow plug relay) it's safe to assume that the LIN bus signal is physically getting to the alternator from the ECU.

It is error 2263 in Xentry. The following comes up when you try to run the alternator test. What is most interesting is that it comes up in the quick test as an 'i' (event) not a 'f' (stored fault) or 'F' (current fault).

Alternator diagnosis
Possible cause and remedy :
- Check electrical line between component N3/9 (CDI control unit) and component G2 (generator) for contact and routing and (or) line breaks.
- Test wiring from component N3/9 (CDI control unit) to component G2 (generator) with an ohmmeter for short circuit (positive or negative) and repair, if necessary.
i Connect test wiring harness with socket box with component N3/9 (CDI control unit) not connected.
Other possible cause of fault :
- The alternator regulator is defective
End of test

Going to order a genuine Mercedes remanufactured alternator. Tired of playing the merry go round with NAPA refurbished units. Hopefully with them selling me 2 lemons they will give me my money back. They are $650 instead of $200 but well worth my time and peace of mind.

Seems like a reasonable diagnosis to me, why is the alternator a networked device? Are they doing some sort of trickery to bias the alternator charging scheme to periods of deceleration or something? What is the text associated with the 2263 error?

Alternator
 

Going to order a genuine Mercedes remanufactured alternator. Tired of playing the merry go round with NAPA refurbished units. Hopefully with them selling me 2 lemons they will give me my money back. They are $650 instead of $200 but well worth my time and peace of mind.[/QUOTE]

Having dabbled with my two W211s on can bus issues the Alternator has to be the backbone of reliability. Another option to going OEM is a Bosch New Unit. I recently ordered one from Pelican and it would be the same as a new MB unit which would likely be be a remanufactured.

I am dealing with a front passenger side SAM unit defective right now and some of these modules are starting to be become rare, the one I need is not in the USA and none in stock in Germany. Supposed to be 4 weeks. The bummer on these newer gen tech cars is if your SAM units/ECM units go there is no subsitute for not getting new modules. You can find used ones, but dealers will not program used parts and unless you have a really old version of the Xentry there is no offline coding available.

The LIN bus is a one wire low speed serial link used for comms that are not as critical or sensitive as those requiring full two wire CAN. The 642 uses this for the glow plug relay (starts and stops the glow cycle, reports bad glow plugs back to the ECU) and for the alternator it provides tighter regulation than the traditional feedback wire method. There is a current sensor at the battery so the ECU can make charging decisions based on current demand on the system. Such as telling the alternator to stop charging while at idle and low demand to reduce drag on the engine, or killing it at full acceleration to reduce the load on the engine. By dumping the field excitation to zero, the alternator basically produces no electricity and just free spins. Combined with the freewheeling clutch the alternator drag can be reduced to nearly nothing on demand. All to chase that almighty drop of fuel savings....

It appears the default behavior in the event of LIN bus loss is to maintain 14.2-14.4 V on the bus whether it needs it or not. It does inhibit the booster heater in this condition.

The error text was in my post above in italics.

I was able to get the alternator for around the mid $400s with exchange, or double what NAPA charged. This is a remanufactured unit certified by MB. I need to turn in a core at MB so I am going to just give them the NAPA unit since it will be almost $200 more without the core.

I will be pulling the alt tomorrow evening when I get back from my trip and swapping it Thursday morning at the dealer. Also ordered up new brakes, rear pads and rotors, front pads, so I have another weekend project ahead for this car.

I am too concerned about electronic module failure killing this car. I am glad I was able to save the ZGW module on this car, I guarantee it’s not cheap at the dealer.

Front SAM
 

I have been awaiting the arrival of the front SAM unit for several weeks and it is still showing not available in inventory in the US or Europe. They do not give you a eta when it is awaiting to be made apparently.

So, I have bought a used one. (hope it is good). Taking it to a independant shop with subscription service Xentry to get it coded. I downloaded the code from my SAM onto a thumb drive through my Chinese Xentry, but I cannot upload to the SAM with the C4 version as it looks for a server login.

Working with the CAN-BUS is cumbersome as the vehicle gets older in my opinon but I sure like the W211s!

Yep that is the problem with the cloned diagnostic units. It’s worse on a 212 and 166, not only can you not upload to the modules, you can’t do the download nor change options (version coding) without logging in. All you can do is scan for faults, run the guided tests, and you can write to the maintenance log (when completing services). Granted that is better than nothing but going forward they really have it locked down.

It’s like the gps maps, on the 211 you can just pop a dvd in there and as long as the data is valid (Meaning a good copy) it will accept it. On the newer models the map comes on an SD card that is hard coded to the VIN. Meaning that you have no choice but the dealer.

On my 211 I bought an EBay copy of the last update that will ever be made (2014) for about $20. MB still selling for $350. I normally don’t advocate piracy (I write code for a living so yeah it’s personal) but come on guys, I am not paying $350 for a 5 year old map that has no support path going forward. I just got tired of it telling me I was off the road every time I drove on a section of roadway near my house that was reconfigured in 2005.

So that same thing will happen to the later models.

I think you are going to see people start offering board level repair of these modules as a service. There are people out there with access to specialized tools and knowledge to be able to troubleshoot these boards.

I found my notes, here are the 4 modules that participate in both buses:
N93 Central Gateway
N80 Steering Column Controller
A1 Instrument Cluster
N73 Ignition Switch

New alternator came in yesterday at the dealer. Valeo factory re-manufactured at the Valeo factory in France. MB logo on the part number label. Looked like a new alternator.

Got it installed last night and car now scans completely error free on the quick test.

I started it with the voltage on the display and it appears the LIN bus connection holds off the alternator from starting its charge until the engine gets up to speed and stabilized (or about 10-15 seconds) after start. So much so that I thought it was not working at first.

Without the LIN connection the alternator just starts making 14.xx V right away. With the connection, the alternator slowly walks up to full output once the engine is stable. So the alternator definitely defaults failsafe on comm loss which is a good thing. It just doesn't have the optimized operation without the comm link.

Some tips for alternator replacement on a 642 powered W211 sedan. I suspect the steps will be similar for the W164 and probably the W221.
- I recommend you go ahead and procure the gaskets and seals on all the joints on the intake tract. If you just put it back together with the original seals you will end up blowing black crap all over the front of the engine.
- You will need E10 and E12 sockets, 7 mm (for Y-pipe) 13 mm (for the B+ terminal) and a T20 bit.
- All references to left and right follow vehicle convention, left = driver, right = passenger (for a LHD vehicle).

- first be sure to disconnect the battery. Put a big note to self not to shut the trunk while the battery is off as the trunk is electrically released.
- jack up and remove front and center bottom covers. You can do the whole thing from the top at least for removal but for replacement you will probably have to work it from below. You do need to be able to unplug the intercooler air hoses from the intercooler to get them out of the way, thus the need for lower access all the way up front.
- Next will be a plastic cover over the belt drive. There are two E10s on top and the bottom is held by a ball and socket plastic tip at the bottom of the cover. Pull hard straight up.
- Take off the triangular resonance pod above the mixing chamber (right side). 3 x E10.
- Take off the left and right intercooler hoses from both ends and remove them to get out of your way. The spring clamps are a little tricky, you just find one end and slide back about an inch or so until it clicks in the released position. This allows you to remove or insert the hose. Then when you've reinserted the hose you just snap the spring clamp back to the locked position. Be ready you are going to get a drop or three of oil out of these.
- Take off the discharge side muffler (down front on left) and the silver tube coming from the turbo outlet. 2 x E10 on the muffler, T20 on the clamp between the muffler and the silver tube, deep E10 on the stud holding the silver tube. Pull the muffler and silver tube out of the car. Mind the o-ring at the turbo outlet, that is probably hanging inside the female end of the silver tube, it needs to be on the neck of the turbo when you reassemble.
- Take off the Y-pipe, the right side air box, and the right side air box intake tube. The left side air box can stay.
- Unplug the glow plug relay B+, glow plug relay connector, pressure sensor (up front on mixing chamber), servo valve (on top of mixing chamber), temperature sensor (behind mixing chamber).
- Remove the two E10s holding the right end of the mixing chamber to the bracket supported by the engine. This is right by where the intercooler return hose plugs in.
- Remove 4 E10s at the top end of the mixing chamber, where it attaches to the intake manifolds. This is right at the center of the V. There are 2 bolts right next to each other at the top of the connection. One holds the fuel hose bracket and the other actually attaches to the manifold. Don't mix up these bolts as they are all different lengths.
- Remove the last E10 holding the mixing chamber, that is on the bracket that also holds the glow plug relay, going into the manifold next to the vacuum pump.
- Grasp the mixing chamber and gently pull forward. It will take some persuasion if it hasn't ever been removed. Gently wiggle and pull and it will come off. More oil drops.
- Remove the bracket that holds up the belt cover (2 x E10).
- Put a 17 mm or a big E-torx (my set didn't go that high so I used a 17 mm) on the end of your breaker bar. On the belt tensioner there is a cast E-torx fitting that is at the bottom of the tensioner assembly. Put your bar there and rotate counter clockwise to release the tensioner. Don't use the bolt at the center, that is the bolt that holds the tensioner to the engine. Pull the serpentine belt off.
- Remove the little bracket that held the tail end of the mixing chamber to the head. 3 x E10, 2 of them are shared with the heat shield over the exhaust manifold. When you go to put this all back together, start these screws but do not tighten them until you have attached the bracket to the mixing chamber.
- Cut the two zip ties holding the wire pack to the bracket above the alternator.
- Using a 13 mm (double check you did lift the battery negative first) remove the B+ connection from the alternator. The terminal cover is probably going to be brittle so be prepared and get another when you order the alternator.
- Unplug the LIN bus connector from the back of the alternator.
- Loosen the 4 E12s holding the alternator to the block. Guide the alternator out the top past the radiator hoses. The bottom rear bolt will not be able to be removed with the alternator in place because it hits the sway bar. Likewise the top rear bolt hits the wheel well. So you will be lifting it out with the bolts still in the pockets.

Putting it back together:
- Alternator back in, remember to pre-load the two rearmost bolts and the bracket before setting the alternator in place. Also load two new zip ties in the bracket while it is out, much easier to do now than once it is in place. 20 Nm on the 4 big bolts.
- Hook up alternator B+, 15 Nm, don't forget to plug LIN bus connector back in. Dress the wire pack and secure the zip ties on the bracket.
- Put the belt back on
- Cover bracket, 12 Nm
- Mixing chamber bracket, these are all 9 Nm, leave loose.
- Mixing chamber, all 9 Nm, watch the harness routing to the glow plug relay. Go ahead and plug everything back in on the mixing chamber. Go back and torque the 3 bracket bolts, 9 Nm on these too.
- Turbo outlet tube and muffler, bolts to block are 12 Nm, the T20 clamp screw is 6 Nm, the stud holding the tube to the manifold is 9 Nm.
- Intercooler hoses, be sure they are inserted all the way, the spring clamp is locked, and they pass the 'tug test'.
- The little triangle resonance pod on the mixing chamber, 9 Nm.
- Belt cover, 9 Nm.
- Y-pipe and right side air box.
- Bottom covers.
- Reconnect the battery. Reprogram the limits on the windows and the sunroof. The clock should set itself once it finds the GPS signal (assuming you have navigation option as most 211s did).

When you go to start it, get in and shut the door. Turn key to 1st position and set the LCD so it is showing '0 mph'. Press and release the instrument lamp dimmer knob 3 times quickly. It should show 'Ub = 12.x V'. Start the engine and verify that the voltage climbs into the 14s within about 10-15 seconds.

If you have Xentry then hook it up and go into Control Units/Drive/CDI 5 - Common Rail Diesel Injection/Guided Tests/Alternator Test and follow the prompts.

Wow. Very comprehensive and detailed list - I'm sure it will come in handy for someone in the future.

I've changed the alternator in a W211 OM648 version and I sure don't recall it being anywhere near as involved as your list. I guess the OM642 engine bay is way more complicated?

I realize the LIN data bus isn't a very complex or expensive set-up and was custom made for this sort of application but I'm just not sure the added complexity of having a computer networked module living inside the alternator is a cost/complexity thats worth the benefit. Electronics isn't my strong suit but it just seems like the standard voltage regulator methodology would be 95% as good?

I guess one side-benefit of having a LIN networked alternator is that you could bias the charging scheme of the alternator to take advantage of deceleration?

I mean how much fuel could that save? An ounce a tank? Maybe?

If a MB dealer or independent shop was working through this problem, I wonder how many on this list would be screaming that they could not fix the car the first time, that the dealer is just trying to sell them an alternator they don't need and end up trading in the car never finding out that it really needed the other fixes and an alternator?

Nice post lots of good information. I can't help to think that economical vechiles sure cost a lot.

I’ve had this car since spring of 2018. I bought it for $9k cash from a private seller. It had 179k on it then, now it’s about to turn 200.

Car did not have OE windshield when I bought it. Cracked soon after I got it and replaced for free (SC law requires your insurance to provide zero deductible windshield replacement if you have comprehensive).

Glass man (local independent shop recommended by dealer) commented on crappy job done previously and he spent time doing it right with a MB genuine glass.

So I really think the ZGW corrosion started by hack windshield install letting water in.

Likewise an Indy garage did the oil cooler seals but did not replace the intake tract gaskets. Which blew black crap all over everything on the front of the engine.

So these two faults caused by improper repairs.

Only other thing I have had to do is rebuilding front suspension, that comes with the territory of getting to 200k miles. And about to replace the back pads/rotors (probably original) and front pads for probably the 4 or 5th time in its life.

And a VGS replacement, went dealer on this as I wasn’t brave enough to try the ebay sensor replacement route.

Except for the hiccups with the ZGW and VGS it has been quite reliable.

older cars discussion..
 

I too have pondered many times the logic behind buying an older used car (mainly a Benz in my case) and economics. I have bought several W211s and a w124 with alot of miles on each, very different experiences on all of them. However at the end of the day it is so much cheaper to drive/repair an older car i feel since i am doing 90% my own repairs than take it on the chin i with a new car (say 60k) and depreciation/upkeep as well.

I can drive a older W211 for 150k miles for the price of a year payments on a new car. Granted I have the inconvienence factor as repairs are needed sometimes when you least need them but I do not have cash to burn!