I own a 2018 C300, I bought it as a used car about 2months ago at 19k miles still under manufacturer's warranty.
This car was a lease car before I bought so maintenance was always done by a MB dealer in CA according to carfax. (I live in TX)
As soon as I bought the car, I brought it to a local Valvoline oil change shop to change the oil and was told that they are going to vacuum the oil from the top not to break the oil plug. They told me this is the same way MB does when they change the oil because the drain plug is so fragile.

Around 2 weeks ago I noticed oil leak, a few drops a night so I brought it to a local MB and they told me it's leaking from the plug but it cannot be repaired with warranty because someone who changed the oil last time did something wrong - like exerted too much torque or something. They quoted 340 for the repair + 60 for clean up. They would have charged me an extra for oil change it they repaired.

As they refused to repair under the warranty I had to buy the oil pan and brought it to a local car repair shop to get it done. paid 80 for part and 110 for labor, they salvaged the oil since it ran only 1~2k.

It's already a done deal but I could not accept it so brought this up to MB USA, but they said the dealership's interpretation to warranty policy is correct.
But as I was talking to them I knew that they have the carfax of my car and they knew I changed the oil from Valvoline. I explained that I witnessed when they changed the oil and they sucked it up from the top and told them there's no evidence that the last oil change is the root cause of the leak. If it was the cause why it had been okay for a year and started leak just a few weeks ago? However their stance did not change. I asked them to help me file a claim to the MB dealership in CA who touched the plug last time but they said they cannot help but I need to figure the way and do it by myself.

Now I have a strong belief that the local dealership saw the carfax at the first place and tried to charge me knowing that the last oil change was made by others. And now they don't want to take it back what they said.
This is an awful experience both with MB dealership and MB USA. What you guys would do?

 

How does Valvoline know Benz plug is weak unless he is trying to hide something?

Valvoline shop high school kid/tech probably went from bottom plug and used an impact gun. After supervisor seeing the kid had held the impact gun to the drainplug after draining the oil for over a minute, the supervisor decided to inform the customer, extraction from top on already drained engine oil to cover it up.

They claim the drain plug is flimsy and weak. Well it's not. Drain pan and plug is well made compared to jap brand like Toyota or Nissan.

 

I'm leaning towards what stockbmw is thinking. Something smells fishy in tuna town. Quick oil change shops are a game of Russian roulette IMO. Just a matter of time until you take one straight in the wallet.

I would not put much faith in CarFax data. I had a car that was involved in a front collision, did not deploy the air bags, but needed a new front bumper, right fender and hood. All work was done at a dealer. When I went to sell the car, it had a clean CarFax! More recently, the C300 I now own, I bought used in 2018 (lease turn-in) and had a clean CarFax. I didn't know it at the time, but as I've lived with the car and it has aged and from doing my own work on it, I've discovered the entire rear of the car has been repainted and the right-rear quarter panel has a huge patch of body filler. The sanding marks are visible in the filler and the paint on top of the filler is starting to blister now. The rear bumper that came with the car had paint drips down low in the finish. MB factory paint does not have paint drips in the flats, lol

CarFax is only as good as the data they receive, which is not consistent at all from what I've seen with my own eyes.

Good luck with your oil leak issue!

 

At Valvoline you stay in the car while they change the oil. They did not even remove the bottom cover plate. And the leak started almost 2 months after the oil change. When I called a local repair shop the mechanic told me to get a new pan plate not even take a look, said he’s repairing the same thing for another 2020 c300. All are fishy, especially my local MB dealership is kind a rude and I felt they look down on customer how brings used entry models.


Thanks, after I spent 200bucks out of my pocket the leak stopped. It’d be less frustrating that i was fooled by Valvoline than was succumbed helplessly to the dealership.

 

Yeah, bummer. But hey, the best ending is that even with the cost of the Valvoline + the $200 pan, you still saved about 50% of a single oil change at a MB dealer. Sweet! lol

 

Facts! That door rate (labour rate basically) at the dealership is certainly way higher.

 

The dealer saw Valvoline on Carfax and wanted any excuse not to repair the car under warranty. Valvoline was his perfect excuse. MB dealers go crazy when they know the car was touched by others especially when its under MB warranty.

 

"Thanks, after I spent 200bucks out of my pocket the leak stopped. It’d be less frustrating that i was fooled by Valvoline than was succumbed helplessly to the dealership."

I applaud you for finding your own solution, buying your own parts and having an independant install saved you $210 and a condescending MB dealership didn't get the work.

I would recommend finding a good independant Mercedes shop to handle even oil changes. (Two near me hire only factory trained former Mercedes dealership service writers and mechanics and is fully equipped with MB factory software, tools and equipment)

The quicky oil change places are notorious screw-ups (not saying that is the case with yours)

 

I am new to this MB eco system. the MB dealership in my town is really sly. I should go another one next time to see all are the same.

 

Thanks for the tip. I am leaning toward starting to DIY on oil change too.

 

I experienced a very similar thing with a different brand vehicle. It wasn't an oil plug though. Non-dealership did a maintenance and it went wrong. All dealerships in my city laughed at me when they saw the record in the Carfax. I called the headquarter but so did they. As I believed it was caused not because of the non-dealership maintenance but because of a design flaw, I prepared evidences, photos, and possible theory why it's a design flaw. Before hiring an attorney, I went through a non-profit organization. Well... even before we started working, the vehicle headquarter sent me a settlement agreement in a few days along with a check more than enough to cover the repair. PS: It was a design flow. Same things happen to other vehicles later.

However, I don't think the oil plug could be stripped unless someone fastened it wrong. If it happen to you, you can retap the thread and put an oversized plug. It's simple and correct fix.