Hi all,

The radiator fan on my 1 year old GLC43 recently started kicking in almost every time the engine is shut down (even on short trips) although operating temps look to be well within normal range. The fan then runs for about 5-7 minutes at pretty high speeds before turning itself off. Dealer tells me this is normal for cars with “large engines that run hot”. Granted it is hot all year round where I live but this doesn’t seem like normal behavior.

Just curious if your cars do the same?? Thank you!!

Your dealer is correct. It's normal and very common for engines that have the turbos nestled between the cylinder banks. The so-called Hot V layout. For any kind of driving that makes your turbos spin it gets hot in there and if you don't drive around enough with the turbos not making boost to cool them down, you'll find that the fan kicks in after you park in order to cool down that area of the engine. It pretty much just takes a couple of accelerations to get things hot and especially if ambient temperature is already hot. The fan keeps blowing air over the turbos until they cool down enough to avoid cooking the oil. Turbos can and do get glowing hot. Compressing air produces a lot of heat.

Not OP but good info - how much driving around would it take to get the turbos cooled? I don't even have the car yet but I'm wondering if it's worth going into eco (or somehow otherwise not using boost) when coming up on my destination to help them cool off.

Completely normal and welcomed behavior. It's similar to a turbo timer but without the need to keep the engine on.

That all depends on how much heat there is to dissipated. For daily driving I generally don't worry about it with my C63S. I often do a couple of acceleration spurts in the last 2 miles which then results in the fan running, but if I go for a hard canyon run, I watch the oil and tire temperatures and wait until they've come down to what I normally see for normal driving before parking the car. That gives the brakes and everything time to cool down while cruising on the highway. Usually that takes a few miles of just cruising.

Much appreciated! I was concerned that it might be a bad cooling fan circuit or temperature sensor, but sounds like it might just be a combination of MB tech trying to prolong my engine life given the scorching hot ambient temps where I live.

Obtain a detailed (4 pages approx) of your build data. You will see what type of radiator, AC and oils etc . Our cars come with a Hot or Middle East climate profile in Australia, even though we have cool and temperate climate zones including skin melting areas. Build state may give you some indication and if set for cool climate, speak with Dealer re type coolant and oils for your hot region. But yes they do have a run on after switching off that will run for a while, even when starting sometimes when outside is 37C and your cabin thermostat is set to 19C for comfort.
Happy motoring.

Having similar prob to original poster with fan/cooling issue:
A few days ago we traded in our 2021 GLE 63 S (too big for my wife) on a GLC 63. Ck engine light came on within a few miles. Coolant issue. CPO? What a joke. We returned to the CPO selling dealer Gainsville MB and they couldn't find the time do do a quick hook up to the computer. Now at home in Savannah Critz MB who has a dismal reputation. Car in for 3 days now. I want to get regional rep or corporate involved. Can someone give me contact info so I can escalate this?
TIA

That same thing happened to me on a 2024 GLC. I drove four or five miles in the fan kicked on at high speed for at least 5 to 7 minutes. All temperatures look normal, even oil temperature was normal. Call the dealer and they wanted to do the same thing by taking the car in for 3 days, they did say perhaps sooner but you know how that goes. It then threw an engine light on the dash and said there is a coolant problem in your performance will be degraded. I recycle the engine a few times to reboot the system and the engine light went away and also receiving the gas cap.