C Class (W205) C 180 BlueTec,C 200 BlueTec,C 220 BlueTec,C 220 BlueTec BlueEfficiency,C 250 BlueTec,C 300 BlueTec Hybridplus,C 180,C 180 BlueEfficiency,C 200,C 250,C 300,C 400 Plug-in Hybrid,C 400

A/C Heat Issue? Please advise 2019 C300C Sport - Purchased just one month ago

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old Mar 1, 2019 | 02:55 PM
  #1  
Brittnie Jane's Avatar
Thread Starter
Member
 
Joined: Aug 2018
Posts: 153
Likes: 19
From: Louisiana
2019 C300 Coupe AMG Sport Package
A/C Heat Issue? Please advise 2019 C300C Sport - Purchased just one month ago

1/24...So, it's been pretty cold here in Louisiana and I've noticed that when I have the air set to let's say 80 (bc that's what I had it set to this morning) my vents blow hot and cold air out, not only that, it will switch up which vent(s) are blowing hot and cold air. It does this with a/c set to off and also on.
I will feel warm air then all of a sudden I get hit with cold air or one or two vents will start blowing cold air and one or two warm air.
Is this normal for this model and year or is something wrong?

1/31...I took it to the dealer, the tech stated that he felt the air doing as I explained. He ran a diagnostics test and it came back normal. He stated that everything was normal, it's just the car trying to balance the temperature, "The air system has a lot of flaps that open and close."
I just don't agree that this is normal, 80 should blow 80 consistently.
Also, he also stated, "Try changing the settings to just dash vents and not floor and dash or defrost and dash vents." I've tried all of that for one, two, I shouldn't have to do that not run my defrost to keep the heat consistent.

2/25...Just a little update, I will be taking my car in for service this Wednesday. A few days ago I tried to use the heat and it was cold, no matter what I did it would only blow cold/cool air. It was not very cold out this particular day, however, I had been at work and was freezing from the a/c.
It really seems like the outside temperature is affecting the heat and cooling system. It's like, it's warm out you don't need heat today! Today it is chilly out and the heat is working fine as of this morning.

2/29...Brought the car in yesterday at 7:00am, they called me to come back at 1:00pm, they could not replicate the issue(s). I was yet again so aggravated that they could not find the issue. We got in it and I drove it around with my actual salesman and the a/c heat system immediately started malfunctioning, he was like, "Oh, okay, it's definitely not supposed to be doing this. Something is definitely wrong.

3/1..." We verified temperature difference. I verified this with two other C Class vehicles on our lot and they are all performing the same way regarding blend functions for mixing ac/heat. "-Service Advisor

Last edited by Brittnie Jane; Mar 1, 2019 at 02:59 PM.
Reply
Old Mar 1, 2019 | 03:04 PM
  #2  
Mikey53's Avatar
MBWorld Fanatic!
Veteran: Air Force
10 Year Member
Liked
Loved
 
Joined: Nov 2015
Posts: 1,193
Likes: 302
From: Oklahoma
2016 C300 4Matic traded in for a 2022 E450 Coupe
Are you using "auto"? Mine doesn't behave the way you described. Of course I've never set mine to 80, which I would call BBQ mode
Reply
Old Mar 1, 2019 | 03:57 PM
  #3  
Brittnie Jane's Avatar
Thread Starter
Member
 
Joined: Aug 2018
Posts: 153
Likes: 19
From: Louisiana
2019 C300 Coupe AMG Sport Package
I've tried auto no avail. I've tried all different settings and variations. 80 is warm in my car on a cold day, I'm very sensitive to cold.
Reply
Old Mar 6, 2019 | 11:53 AM
  #4  
Brittnie Jane's Avatar
Thread Starter
Member
 
Joined: Aug 2018
Posts: 153
Likes: 19
From: Louisiana
2019 C300 Coupe AMG Sport Package
My salesman and I drove it and got it to replicate the issues, they are ordering a new control panel.
Also, now my passenger side window has decided to malfunction and stop working off and on. Ughh!
Reply

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.


All times are GMT -4. The time now is 10:08 PM.

story-0
6 Mercedes Models That Did NOT Age Well (But Are Somehow Still Cool)

Slideshow: Not every Mercedes design becomes timeless, some feel stuck in the era they came from.

By Verdad Gallardo | 2026-05-12 18:09:07


VIEW MORE
story-1
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun

Slideshow: Yes, Mercedes built manual cars, and some of them are far more interesting than you'd expect.

By Verdad Gallardo | 2026-05-02 12:36:58


VIEW MORE
story-2
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren

Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.

By Verdad Gallardo | 2026-04-29 11:19:28


VIEW MORE
story-3
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine

Slideshow: Before curves took over, Mercedes mastered the art of the straight line, and some of those shapes still look right today.

By Verdad Gallardo | 2026-04-25 12:05:49


VIEW MORE
story-4
Flawlessly Restored Mercedes 190E Evo II Heads to Auction

Slideshow: The 190E Evolution II shows how a homologation necessity became a six-figure collector icon.

By Verdad Gallardo | 2026-04-22 17:53:47


VIEW MORE
story-5
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know

Slideshow: Mercedes is turning one of its core nameplates electric, and the details show just how serious this shift is.

By Verdad Gallardo | 2026-04-21 13:58:06


VIEW MORE
story-6
Mercedes EQS Gets A Major Update: Everything You Need to Know

Slideshow: Faster charging, longer range, and a controversial steer-by-wire system define the latest evolution of Mercedes-Benz EQS.

By Verdad Gallardo | 2026-04-15 10:35:34


VIEW MORE
story-7
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve

Slideshow: These overlooked Mercedes-Benz models never got the spotlight, but they quietly delivered more than most remember.

By Verdad Gallardo | 2026-04-13 19:35:45


VIEW MORE
story-8
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping

Slideshow: A well-used 1991 Mercedes-Benz 300D with more than one million miles is now looking for a new owner, and it still appears ready for more.

By Verdad Gallardo | 2026-04-10 10:05:15


VIEW MORE
story-9
10 Most Reliable Mercedes-Benz Models You Can Buy Used

Slideshow: From bulletproof sedans to surprisingly tough SUVs, these Mercedes models proved that the three-pointed star can go the distance.

By Verdad Gallardo | 2026-04-08 09:55:49


VIEW MORE