Hi guys,

First time Merc owner here. Wish you could help.

Bought an used GLC43 2 months ago. Completely love it when driving, nothing to complain except the crabbing issue compared with my previous AUDI Q5 3.0 TFSI.

The other day after about half an hour driving, I've noticed a strong metal and rubber burning/heating smell when I jumped off my car. So I walked around the engine bay area and noticed that the smell is from the engine bay.
Standing in front of the car, I can feel the heat coming from the grill with strong metal/engine smell. It smells normal but very strong and intensive compared other cars I've had. Then moving to both side, the smell comes from the wheel arches/wells with rubber heating/burning smell. It seems like the heat escapes from the wheel arches heats up the tyres and makes that rubber smell.

Here are some background information: comfort mode, normal driving, outside temp 15 C, water temp 3 white and 1 red left, oil temp 97C.

I went to local dealer the other day, and was told diagnosis shows nothing abnormal, and the service manager explained to me that the heat is because there are turbos on each side. It makes some sense for the massive heat from engine bay but not really persuasive for the tyre heating smell. So I'm seeking a second opinion from the owners here.

Sorry for the long story. That's really annoying as every time when I get off the car, I can smell it, and I keep worrying if there's something wrong. I've had 2 AUDIs with 3.0tfsi and a few 2.0T cars and never ever had such issue. Only once I smelled the engine heating smell was when I spirit drove my FOCUS ST in the mountain for over one hour.

My questions are:
1. Are you experiencing the same massive heat from the engine bay?
2. Is the heat coming from your wheel arches and making the front tyre smelly?

Thanks a lot!!!

 

Great question! I had this "issue" with my brand new GLC43 as well. Very strong smell after just normal driving. Hood felt really hot as well. After some break in time that went away and all is normal now. I wouldn't really worry about it as I did. The "smell" and all that went away after some driving and putting some miles (kilometers) on the car.
Hope this helps.

 

My 63s is an oven under the hood and the fan runs many minutes after the car is shut off each time. It's a beast and I drive it like a beast so I would say it's normal for that engine.

My last 2 AMGs had that smell when they were new but quickly wore off.

 

Hi CroMecka,

Thanks for your reply. But my car is an used one having 25k on the clock. So there wouldn't be any strong smell comes out. So you have nil smell from the grill even it's so hot? I can smell the hot engine odour but it's like 2-3 times stronger than my other cars regardless they are 3.0t or 2.0t.

The thing bothers me more is the heat/hot air from the wheel well that heats up the tyres and makes the rubber burning smell. I haven't had any experience that the hot air/heat would come out from that area, and if that's the case, then would the tyres be aging so fast under such a hot atmosphere. Much appreciated for sharing your experience. Thanks.

 

Hi ParadigmDawg,

Thanks for the info. Can you feel the hot air/heat coming from the front wheel arches?
I think the heat doesn't concern me as long as the oil/water temp shows normal figure. But the metal smell from grill and the heated rubber smell from under the wheel arch worries me a bit.
Thanks for sharing.

 

Both my cars do this. The m276 biturbo puts out a lot of heat. When it's warmed up I can feel the heat through the front wheel wells. This is normal.

 

Thanks Mr.J. Feeling better as I'm not alone. At least that's not a sign of mechanical failure.
As the heat coming through the wheel well and making the tyres smelly, my garage is full of burning rubber smell after parking. I recently decided to park on the driveway which is really annoying.
Before I bought the Mercedes, I was expecting a better ownership experience. But now I just feel a little disappointed.
It's good car to drive but lack of refinement for details.

 

That is interesting. My wheel wells get hot but no burning smell of rubber unless I have been burning rubber....that actually happens a lot which is likely why I go through 4 tires every 7,000 miles.

 

That's what worries me... But I'm sure the hot air from engine bay has another kind of smell. When it goes through the wheel well, then makes the tyre emit rubber burning smell. I touched the rubber, they were just lukewarm not hot.
Tyres are about 15000km old, not much left now. I just wish that's just the aged tyre itself rather than the heat/hot air causing the smell all the time. Will have new tyres before Xmas as the crabbing is getting worse, you know...

BTW, when you feel the hot air from engine bay, does it smell at all or just hot like a fireplace? Mine smells like a mix of plastic, rubber and metal, bit harsh. My Audi's smell like hot oil, but mild. I sincerely wish MB is better than Audi, however...

 

I have a long day of driving today so I will test it out. I have a very sensitive nose but honestly, I have never smelled anything out of place from my car.

I have had 3 SQ5s and 3 AMGs and I will say that AMG has better fit and finish, way better power, way more aggressive, handles better and is more fun to drive. Audi is smoother, quieter and probably a better daily driver yet I still take the AMG everywhere and the Q5 stays at home.

 

Yeah, my GLC63 had that smell too for a couple weeks. I also worried that something was wrong but it did go away.

 

Okay so I drove 50 miles to see an account and my car smelled normal and no more heat in wheel wells than any other car I have driven.

Then it sat for an hour and then back home another 50 miles. I hit 120 mph one time to make sure it was working hard, pulled in my garage 15 minutes later. Smell was once again no different than any other car I have driven hard.

Not quite scientific, but once in my garage I took a high end digital meat thermometer and floated in the wheel well about half way up. The front wheel well measured 109f and the rear wheel wheel measure 106f.

 

Do you experience jerkiness when the transmission shifts? especially when the engine is cold.

 

100% agree with your opinion about these two brands.
The smell just drives me nuts. When the service manager in the dealership told me it's normal, I just felt I lost confidence with the build quality of MB. Wish I'm wrong as I really like the car...
It still drives like a dream. Every time it puts a smile on my face when I drive with sports mode. But the smile goes away so quickly when I step out of the car and find the annoying smell......

 

Thanks for your reply. Iy looks everyone has no smell issue...

 

Thanks for sharing your experience. I probably need to test the temp with a thermometer to see if it's overheated in there.
BTW, I just realised that the two 3.0TFSI Audi's I had were supercharged, which means much less heat from the turbo. Maybe that's the reason I feel excessive heat from MB. But I haven't had any car that has hot air/heat escaping from wheel well. That's strange...

 

Hi mate,

I don't think there's much jerkiness. But I have noticed when I try to stop at the lights, the down shifts from 40km to 0 is bit jerky no matter it's cold or not. But up shifts are perfect any time...
I haven't had any experience with MB, so cannot comment if it's normal or not. Any ideas? Thanks.

 

Yes, test yours for comparison. I would think mine is in normal range since it's not much different in the back.

Of course we can't compare with each other unless you drive like I did and then pull it into a 100+ degree garage in Texas...lol...

 

Some types of tire shine can get smelly when it heats up. Do you use a lot of it?

 

Thank you. I will try some time next week or so. Quite busy recently... Thanks a lot for your info...

 

Nah... I only use basic shampoo to wash my car. Don't like chemicals... My tyres are just 6-7 months old... weird...

 

I have a 1.5yr old 43. It still gets pretty hot and I have noticed the heat extend onto the fenders. This is more heat than other cars I’ve owned buy I don’t get any smell. MB service should know if you bring it to them while hot and smelly.