Nicholi2007

I'm considering the purchase of a C450 with 77,000 miles. 1 Owner. NO record of transmission on CarFax although likely done.
I've read a lot of threads. it's not always stated what mileage the issue occurs at.

So rather than spend hours compiling or going on old threads for a reply,
I'm reaching out to the community for help, expertise, and advice.

For Example.
🚨 Issue: e.g. timing chain tensioner at 120k miles
Driving Style: Demonic Possession, Spirited, Old Man River, Grandma, Nun.
Tune: Tuned, Not Tuned.

Many thanks!

TABLE OF CONTENTS (In Progress)
LED Door Lights DIY
Timing Cover, Cam Magnet Reseal DIY

Maiq

90k miles
Issues: A/C doesn't blow cold, car shudders and vibrates only when accelerating, steering column height adjustment broken, radiator hoses pop off if you go over 140mph, 2x door handles lights stopped working, camshaft magnet cover oil leak, pan leaks, interior rattling. Never had had a check engine light ever oddly enough..

Driving style: Average for an AMG, nothing unsafe, no skids, burnouts or races, just quick short lived sprints occasionally.

Car is completely stock.

///Parts hard to find, I can't even find a pair of engine mounts..
you'll see with everyone else the main downfall of this car would be it's overall jerkiness, shakiness, weird because the car handles world class it's just not smooth.

I'm going to slowly week by week replace everything responsible for the steering wheel and cabin vibration in the front of the car like the transmission mount, flex disc, CV axles, driveshaft center bearing, tie rods and shocks. I can't tell if it's the tranny shaking or something with suspension but it goes to normal when you let off gas.

I would buy one only if you have $8000 to throw at the car the first year. Unfortunately it seems these newer Mercedes are designed to be thrown away after the exit the warranty period.
I previously owned a 1998 Sl500 r129 and a 1999 C230K Mercedes and they were absolute tanks in every regard.


Hate to say it cowboy this is a great value of a car and is a 10/10 on the fun factor and looks but it's a can of worms out of warranty.

waisoserious

I havent driven my GLC43 in a long time (a year or 2 maybe) but the parking brake sounds like a rocket ship when the metal is bending due to being next to a black hole. Its loud and obnoxious. Apparently its a GLC thing cause the GLC250 and GLC63 ive been in both sound like that.

The moonroof leaks water if you go through a automatic car wash. The water when pressurized and penetrate the seal if it is sprayed at certain angle. Ive had my shoulder drenched before.

Also the suspension rides like its on bricks, even in eco.

Also sometimes the AC smells bad.

Driving Style: Enthusiastic Dad, Properly warmed up, recommended service intervals (by kilometer)
Stage 1 EC with FI Exhaust.

Nicholi2007

I appreciate the info. @Maiq

1. The jerkiness can be solved with a software update possibly. If that does not resolve it then it could be the transmission valve body.
2. Engine mounts. Not sure where you're located. I did hear they were backordered last year but should be back now.
3. A/C - Lots of reasons. AC evaporator, refrigerant leak, low charge. Even simple things such as fuse. Scan the car hopefully it throws a code.
4. I heard door handle lights have been upgraded. Color is likely different though. I'd do all 4.
5. Camshaft magnet cover oil leak is usually at higher mileage.
6. I've heard pan leak. It's normally a bad seal. Hopefully not a bad leak.
7. Interior rattling - Need felt tape.
8. Shudder - It depends at what RPMs. When downshifting? It could be a bent rim or mounts.

It's all solvable but a pain in the ***. Best wishes. It will work out.

SizzlCheez7

2016 C450 with currently 87,000mi. Purchased at 42,000mi 20 months ago with two prior owners in front of me. Clean, and timely maintenance record via Carfax and owner's log. Car is bone stock, and has been a pleasure to own - no large issues really. I use Mobil One Synth 5W-40 Euro blend at 5K intervals (half the recommended mileage, plus stock filters). I have a couple of the door handle lights out; I'm too retarded to replace them on my own - so I just chose to disable exterior lighting through the menu. I located an indie shop here in the Portland area (shout out Matrix Integrated) for all major service work. Upkeep has not been much more than what I became used to in campaigning my prior daily - a 2010 Subie Legacy GT. I have experienced the bucking and surprise stumbles characteristic of the 7 speed transmission, but I have also altered how I drive to avoid those hiccups. A key solution is to go manual if you know you are going to drive asshat-style...especially from a standing stop just after braking. I think I was lucky to find a unmolested car that had been cared for by the prior owners. Have had to change rear pads & rotors (with stock) and had tranny flushed and serviced at 60K.
Quickly changed out from stock rims & runflats after purchase to a summer set up (Conti Extreme Super Sports w/19" TSW) and separate winter set up (Michelin CC+ on 18" Konig Oversteers. Get rid of (or store away/sell) stock rims and run flats as they just create issues & heartaches.
Driving style = ditto as waisoserious. Terribly important for the car's health/longevity to warm up all fliuds/oils to gray zone before switching to Sport+ asshat hooligan maneuvers. Like sex when you are old~

Nicholi2007

Replacing the LED lighted door handles is a bit labor intensive. Like anything the 1st go around is likely the most time consuming.

MB has upgraded the part. 19.20 to 22.00 each plus tax

099-820-01-83-64 (left)
099-820-02-83-64 (right)

Nicholi2007

5K oil changes? WOW. I've heard others do it at 6K.
Official oil change interval is 10,000 miles or once per year.
0W-40 or 5W-40 depending on climate. Higher altitudes should opt for 0W.

My View:
If you have tuned the car, I would definitely do it early. 5-6K. If it's a hot climate for extended periods of months,I would definitely do early.
I think one could safely go to 7,500 miles on stock (non-tuned) even if do you do a mix of casual and spirited.
I would stick to MB approved oil and filter only.

The only way to know for sure would be to do an oil analysis with blackstone.

I would get a MityVac extractor or something similar.
.

White One

My '016 has about the same mileage (120 km's) and I have owned it for 4.5 years..A few issues initially with those crappy run flats, but took care of that quickly with a set of Michelin PS's..Mechanically not much, Steering up/down, etc needed a new cable, 1 rear brake changeout and the center console door needed a 180.00 (dealer) repair..Mine had an extended warranty and I bought a maintenance package with it..Fit and finish remains excellent with a ceramic coating done 3 years ago..Runs, starts flawlessly, always 91/93 octane, and I really don't pound it much..My last 3 cars have been a CTS-V, S4 and an M5 BMW, this car has been a good one..No drips, leaks, shudders or shakes or it would be gone..Oh yeah, began to notice some funky lights and the start/stop doesn't work lately, but it is the original battery, so I may throw a new one in..If I keep it much longer I will probably require rotors and pads on the front and get the clear coat redone on the wheels...Hope this helps.

Nicholi2007

The run flats have a far too rigid sidewall. Mechanically it sounds very good. Perception is the bi-turbo maintenance needs to be more timely unlike the naturally aspirated.
These cars are sensitive to having the required juice. Otherwise, things start to malfunction like the radio, A/C etc. Any AutoZone can test the battery for free.
It's very likely the battery needs replacement at 6 years. 4-5 years is average.
I usually buy the battery online and pick it up at the dealer as they normally discount parts. I just looked it up. Sale price is $251.18.

Thanks for the input.

SizzlCheez7

I sincerely appreciate the attached link / help on the door handle lights!! I might be motivated to fix them now
Big thanks to a "Super Member" taking the time out to educate us newbies and share knowledge + empower the unwashed masses!

Yes, I suppose I am a bit crazy on the oil change interval of 5K. I figure it's going to hurt my pocketbook less keeping an expensive turbocharged motor bathed in fresh(er) oil than what Mercedes recommends. Chalk it up to PTSD from prior Subaru ownership.

TwoC400s

- First C400 was purchased CPO in 2017 with 7k miles on the clock, currently 101k miles. All maintenance through 2022 was done at dealership via pre-paid service plans and only when the car called for it via the service menu. They wouldn't even sell me a 4th service plan, which I thought was kinda crazy.

The only unscheduled repairs have been cam magnet cover leaks and drive shaft guibos at ~85k miles. I think we're on the 3rd set of rear pads/rotors while the fronts were replaced once. This is my wife's car so driving style can only be characterized as "Elderly Grandmother."

- Second C400 was purchased in January 2022 with a hair over 40K miles on the clock (currently 49k miles). Was immediately taken to the drag strip and flogged. Then a JB4 was added and it was flogged some more, and then tuned via EC Houston and flogged some more (12.51@112.99mph).

I have developed cam magnet cover leaks on driver side, which I'm going to do myself.

The car had nearly new Bridgestone run flats on it when I bought it, and they're almost shot already. Plan is to get Kmac adjustable bits and have it truly aligned when I put some Vredestein Quatrac Pro tires on it.

Overall assessment: absolutely fantastic cars that are an amazing performance/comfort bargain.

Nicholi2007

@SizzlCheez7 You're welcome. Helps me to prepare.
As for oil it's better to be early than late. Spark plugs I'd do at recommended mileage.
Carbon buildup is inevitable but on time maintenance is key.

Maiq

Thanks, I think I just need engine mounts or transmission mount, the vibration feels like it's under the center arm rest makes the cabin shake only when I accelerate, if I let off gas it's smooth as butter..I suspected front CV axles so I swapped them and it didn't really change anything. I see know fcpeuro does have c450 now for $270. I'm looking for transmission mount now, which isn't on fcpeuro.
my a/c compressor's clutch doesn't pop out and looks like it's melted, worked on the hottest day this year, next morning wouldn't go cold. I'll figure that out later, I want the car to at least be enjoyable...new tires all the way around, new rotors .

Nicholi2007

1. I'd scan the car with an OB2 otherwise you won't get a proper diagnosis. It could be the clutch. It could be a bad relay or the A/C pressure switch.
2. Under center arm rest would be transmission mount. I would upgrade this part to the C63 version which has more rubber. It will last longer. Yes it's more money.

I'd rather have more longevity. You can either go with OEM or look for an upgrade with an outside direct to consumer manufacture for the transmission mount.

addendum: Look for a polyurethane mount.

GermanCarShow

"Camshaft magnet cover oil leak is usually at higher mileage."

Mine was at something like 58,000 miles. I made a discussion topic on it.

Nicholi2007

Tuned or not tuned?

GermanCarShow

Not tuned. No track days at the time. Basic sporty driving on street. Previous owner was not reckless/aggressive driver.

Also, as mentioned in another thread, this car had its transmission replaced with very low mileage, like less than 5,000.

Nicholi2007

That's crazy. Just a really bad build apparently.... I've read a range of strange issues with the C450.
I've even read about a headlight control module fail. Many are minor.
The major issues centered around the transmission.

A dealer is trying to sell a nearly fully loaded C450 for 25,600 with 77K miles.
No 360 camera or heads up display but everything else.
I'm trying to get them down as things are definitely going to fail in the near future.
Tough to find a 6 with the options I want for 20K. At least there's a record of the transmission done.

Nicholi2007

Noisy timing chain on cold startup possibilities. I wonder if this gets misdiagnosed.

1. Possible Check Valves and Chain Tensioners. Per MotorReviewer M276 Reliability 2. Camshaft Adjuster Failure. Read about C400 owner having this issue at 71K miles. See this post.



3. Per @mikeyvol comments on camshaft adjuster issue


I've never had any warranty on my naturally aspirated cars but I will with the bi-turbo. See this post that takes a dive on common M276 engine problems.

W205C43PFL

Does the vibration happen at all in comfort or only in sport?

Maiq

Every mode, easier to notice in sports plus. I'm am pretty sure it's the engine mount, transmount, flex discs.
If you coast the car is normal, it kinda jerks a tiny bit when you gas or let off gas (feels like engine is rocking)

I checked the engine with hood up and gassed it and the driver side of the engine went up and the left stayed put.

Nicholi2007

Fix the transmission mount ASAP. That's normally where the majority of the vibration is. You don't want additional stress on the drive shaft. Engine mounts are probably low but likely have some life left.

Maiq

I'm trying to find the transmission mount part number, I think it's 253-240-25-00, I used the mbusa.parts website to verify fitment but it's contradictory and there are multiple part numbers that will fit apparently not sure which one to get because some of the transmount pictures look a little different.
I will be doing the repair myself and will probably record it since there is no video in existence of the procedure.
I used to have the Mercedes wis on my laptop but it got accidentally erased. Anyone know what the transmission mount part number is for certain?

Btw, I also tried to wiggle the main driveshaft under the car it it didn't feel like it was loose, if it was, the center support bearing would've been the culprit.
I know I've got to replace the engine mounts too because the driver side lifts quickly only on that side of the engine when you press the gas while looking at the engine with the hood up.
The engine mounts were replaced 3 years ago according to previous owner paperwork, no mention of transmount however

Nicholi2007

Use one of the dealer part sites near you and send the VIN. Once the transmission mount wears it changes the alignment with the driveshaft. I would not drive the car hard until you replace it.

W205C43PFL

Yup as someone else mentioned, transmission mount is highly likely the cause.