Engine cooling fan ROARS after ignition shutdown
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MBWorld Fanatic!
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From: Corona Del Mar, CA
2019 SL450, 2019 E450 Luxury Trim Wagon, 2024 BMW I7 xDrive60
Engine cooling fan ROARS after ignition shutdown
I imagine this may have been discussed here already and if so, I apologize. The engine cooling fan in my 2022 S580 continues to ROAR—for what seems like five minutes or more—after I turn off the ignition. I thought this had a lot to do with the hot summer weather, but things have really cooled off here recently and the fan continues to do this. Today, I drove the car on city streets about five miles, I bring it back home, put it in the garage and the fan continues to run, at what seems to be a high speed. It is actually quite annoying. My three W222’s I had previously would do this every now and then, but only after long, highway drives on hot, summer days.
Does everyone have the same experience? Thanks.
Does everyone have the same experience? Thanks.
Out Of Control!!
Joined: Sep 2018
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From: unbegrenzt
2017 GLE350 4MATIC
Fans roar when they operate. It's a normal sound of a functioning fan.
The question of whether, and for how long, the fan operates is decided by the powertrain electronics.
The question of whether, and for how long, the fan operates is decided by the powertrain electronics.
Member
Joined: Mar 2020
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From: Philadelphia area
2022 - S580 and 2019 Porsche Carrera S Cabriolet
My former 2021 750i did this almost all the time. My current 2022 S580 has only done this a half dozen times in the 6 months - I have put 7000 miles on the car. In each instance when the fan ran on after I shut the engine, I can relate it to my long/hard driving that drive. So, I believe it happens only when the engine is running hot. You might want to check the coolant temperature gauge before you shut it to get a sense of what may be happening.
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Joined: Mar 2020
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From: Philadelphia area
2022 - S580 and 2019 Porsche Carrera S Cabriolet
Semi idiot gauge….the gauge doesn’t show the temperature gradations but you should be able to readily see if its running on the higher side of “normal”, designed to be fairly central in the gauge. I wouldn’t be concerned unless it runs hot with non-aggressive city driving.
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2022 S580
In my S580 the fan does run after driving but much more after aggressive drives. Doesn’t bother me…seems pretty normal as other cars I have or owned in the past did some sort of variation of cooling.
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23 S580 Executive
A lot of gauges now simply connect to a switch rather than anything capable of reading a measurement; the gauge just shows pure BS controlled by software. As an example an oil pressure gauge may simply have a switch that kicks at 10 psi and everything you see on the gauge is generated by software that doesn't even have any way of knowing actual pressure. You get the low pressure light when the pressure falls below that 10 psi set point without the car ever having known what the pressure was at any time other than being above or below the switch trigger. This sort of thing is very common and becoming more common every year. Temp gauges often work the same way with a switch that kicks at a set warmup temp and one that triggers at a set overheat temp while what you see on the gauge is completely made up. This is exactly what is in my Panamera which shows the same 194 as every other Panamera when warmed up; everything the guage shows is a fiction brought to us by people who think we are stupid. I would presume any gauge to be fake until you can find proof that it actually has a real world connection to a real world sending unit capable of taking a measurement. Even then I would consider what the gauge is showing to be highly suspect until verified with your own working gauges.
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Member
Joined: Mar 2020
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From: Philadelphia area
2022 - S580 and 2019 Porsche Carrera S Cabriolet
A lot of gauges now simply connect to a switch rather than anything capable of reading a measurement; the gauge just shows pure BS controlled by software. As an example an oil pressure gauge may simply have a switch that kicks at 10 psi and everything you see on the gauge is generated by software that doesn't even have any way of knowing actual pressure. You get the low pressure light when the pressure falls below that 10 psi set point without the car ever having known what the pressure was at any time other than being above or below the switch trigger. This sort of thing is very common and becoming more common every year. Temp gauges often work the same way with a switch that kicks at a set warmup temp and one that triggers at a set overheat temp while what you see on the gauge is completely made up. This is exactly what is in my Panamera which shows the same 194 as every other Panamera when warmed up; everything the guage shows is a fiction brought to us by people who think we are stupid. I would presume any gauge to be fake until you can find proof that it actually has a real world connection to a real world sending unit capable of taking a measurement. Even then I would consider what the gauge is showing to be highly suspect until verified with your own working gauges.
I would love to hear what others see on their gauges.
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Thread Starter
MBWorld Fanatic!
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From: Corona Del Mar, CA
2019 SL450, 2019 E450 Luxury Trim Wagon, 2024 BMW I7 xDrive60
That’s a pretty cynical view so I hope you are speaking from personal knowledge of the mechanics. I will tell you that my ‘bogus’ temp gauge does move as the engine warms up. It seems to start at ambient temperature (never at the zero point) then move right as the engine runs…takes just a few minutes to reach “operating” temp.
I would love to hear what others see on their gauges.
I would love to hear what others see on their gauges.
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23 S580 Executive
That’s a pretty cynical view so I hope you are speaking from personal knowledge of the mechanics. I will tell you that my ‘bogus’ temp gauge does move as the engine warms up. It seems to start at ambient temperature (never at the zero point) then move right as the engine runs…takes just a few minutes to reach “operating” temp.
I would love to hear what others see on their gauges.
I would love to hear what others see on their gauges.
This started in the 80s but even earlier with fuel gauges. But let's consider that fuel gauge. Notice how it lingers on full for a while but then goes down at a quicker but regular pace for most of the tank? Notice how it does that on every car? That isn't a coincidences, it does that by design. How about that it goes above full and below empty in most cars; did you notice that? Can the car be fuller than full or still have more fuel when empty?
Gauges have been lying to us for a long time. The water temp is usually going to show something in the 190s on every car now even though modern cars have been running hotter for a quite a while now. But it's a customer expectation so they show the customer what they want to see. This isn't conspiracy theory stuff, it's a known. Remember my Panamera? I can shoot the block with IR and get all kinds of numbers while the gauge says 194, oddly no matter how I drive it gets to that temperature in exactly the same amount of time down to the second. A miracle of engineering and temp controls or do you think maybe a timer is involved?
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From: Philadelphia area
2022 - S580 and 2019 Porsche Carrera S Cabriolet
I understand your comments but I think you are conflating the lack of precision of the gauges, which I get, with them essentially being meaningless indicators, or to use your words, “everything the gauge shows is fiction’. Sorry, I don’t buy it.
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23 S580 Executive
The irony here is that you did in fact do exactly that; you've been buying it all along.
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From: Maryland
'71 280SL /'25 AMG SL63 SE/'24 AMG S63 SE Edition 1/'25 Maybach GLS600/'20 Toyota Sien
This is quite normal. The fan is cooling the turbochargers to prevent the oil form crystalizing thus damaging the turbos.
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2019 SL450, 2019 E450 Luxury Trim Wagon, 2024 BMW I7 xDrive60
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2019 C63CS
The running of the fan when parking the car is very typical for today's V engines that have the turbo(s) nestled between the cylinder banks. The so-called Hot-V setup. This ensures a good response of the turbos, but it gets hot in there, so the turbos need to be cooled. Depends on the engine setup you had/have in your other cars, but I'm guessing they don't have a Hot-V setup. Also a V8 gets hotter than a V6. More cylinders, more explosions per second. But especially in city traffic with constant deceleration and acceleration you are using the turbos constantly, so they are hot afterwards. It should be less likely to happen after a long highway cruise with the turbos not being used for a long period and then parking the car, but even a quick burst of acceleration gets the turbos hot momentarily and if you park it right after then the fan will run to cool things down.
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Joined: Jan 2022
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From: Philadelphia
S580, CLS550, Range Rover Sport
I imagine this may have been discussed here already and if so, I apologize. The engine cooling fan in my 2022 S580 continues to ROAR—for what seems like five minutes or more—after I turn off the ignition. I thought this had a lot to do with the hot summer weather, but things have really cooled off here recently and the fan continues to do this. Today, I drove the car on city streets about five miles, I bring it back home, put it in the garage and the fan continues to run, at what seems to be a high speed. It is actually quite annoying. My three W222’s I had previously would do this every now and then, but only after long, highway drives on hot, summer days.
Does everyone have the same experience? Thanks.
Does everyone have the same experience? Thanks.
Junior Member
Joined: Jan 2022
Posts: 21
Likes: 1
From: Philadelphia
S580, CLS550, Range Rover Sport
The running of the fan when parking the car is very typical for today's V engines that have the turbo(s) nestled between the cylinder banks. The so-called Hot-V setup. This ensures a good response of the turbos, but it gets hot in there, so the turbos need to be cooled. Depends on the engine setup you had/have in your other cars, but I'm guessing they don't have a Hot-V setup. Also a V8 gets hotter than a V6. More cylinders, more explosions per second. But especially in city traffic with constant deceleration and acceleration you are using the turbos constantly, so they are hot afterwards. It should be less likely to happen after a long highway cruise with the turbos not being used for a long period and then parking the car, but even a quick burst of acceleration gets the turbos hot momentarily and if you park it right after then the fan will run to cool things down.
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From: DFW, Tejas!
18 GLE 63
It's called "afterboil." After you shut your car down, temps spike because there's no air flow and no coolant circulating.
It's why people pop their hoods at the track after running a session. The engine (like, block, pistons, etc) is still hot AF and will heat up the engine bay and fluids. You effectively shut off the cooling system, but there is still a lot of heat.
You'll typically see the highest coolant and engine bay temps AFTER shut down, not during. For obvious reasons, it's more prevalent with turbo engines than NA. Some cars even have auxiliary pumps that pump coolant (but that's probably indicative of poor engine block design). My race car (BRZ) is notorious for overheating coil packs. They would always overheat on my warm up lap. It would happen on hot Texas days and cold days as well. Well, after enough tries, I finally realized they were overheating AFTER my sessions, and as soon as I'd go put some load into my engine where I'd need a strong spark, the symptoms would show. I started popping my hood after a session and haven't had a problem since. I felt particularly stupid because in my previous professional life (~20 years ago) I designed powertrain cooling systems for two different companies :facepalm:
It's why people pop their hoods at the track after running a session. The engine (like, block, pistons, etc) is still hot AF and will heat up the engine bay and fluids. You effectively shut off the cooling system, but there is still a lot of heat.
You'll typically see the highest coolant and engine bay temps AFTER shut down, not during. For obvious reasons, it's more prevalent with turbo engines than NA. Some cars even have auxiliary pumps that pump coolant (but that's probably indicative of poor engine block design). My race car (BRZ) is notorious for overheating coil packs. They would always overheat on my warm up lap. It would happen on hot Texas days and cold days as well. Well, after enough tries, I finally realized they were overheating AFTER my sessions, and as soon as I'd go put some load into my engine where I'd need a strong spark, the symptoms would show. I started popping my hood after a session and haven't had a problem since. I felt particularly stupid because in my previous professional life (~20 years ago) I designed powertrain cooling systems for two different companies :facepalm:
Last edited by Lawineer; Nov 29, 2022 at 12:54 PM.
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From: ukraine
S580 MAYBACH Z223
I imagine this may have been discussed here already and if so, I apologize. The engine cooling fan in my 2022 S580 continues to ROAR—for what seems like five minutes or more—after I turn off the ignition. I thought this had a lot to do with the hot summer weather, but things have really cooled off here recently and the fan continues to do this. Today, I drove the car on city streets about five miles, I bring it back home, put it in the garage and the fan continues to run, at what seems to be a high speed. It is actually quite annoying. My three W222’s I had previously would do this every now and then, but only after long, highway drives on hot, summer days.
Does everyone have the same experience? Thanks.
Does everyone have the same experience? Thanks.
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Joined: Nov 2024
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Mine W223 S350d cooling fan just roared for 15min or so
This happened to my W223 S350d first time after 6month of ownership. Should I take it to the dealer?
I imagine this may have been discussed here already and if so, I apologize. The engine cooling fan in my 2022 S580 continues to ROAR—for what seems like five minutes or more—after I turn off the ignition. I thought this had a lot to do with the hot summer weather, but things have really cooled off here recently and the fan continues to do this. Today, I drove the car on city streets about five miles, I bring it back home, put it in the garage and the fan continues to run, at what seems to be a high speed. It is actually quite annoying. My three W222’s I had previously would do this every now and then, but only after long, highway drives on hot, summer days.
Does everyone have the same experience? Thanks.
Does everyone have the same experience? Thanks.
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