2017 C43 OVERHEAT ISSUES
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Joined: Apr 2025
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2017 C43 OVERHEAT ISSUES
So guys, it's been like a month or so that my C43 is showing up to 110-115c in the middle screen when I drive it for more than 30 minutes. When I drive it in Sport or Sport+ it happens a lot faster.
The radiator fan also start sounding crazy high like really loud and vibrating when it pass the 102-103c temp range.
It first had a coolant leak and I fixed it by replacing the radiator, I then replaced the water pump and the auxiliary water pump as well as the radiator fan, but none of that has fixed the issue.
I don't know what to do know, I can't recreate the problem after replacing multiple parts, a mechanic told me the radiator fan wasn't OEM so it's running bad because of that, and somebody else told me that it could be the thermostat because there's a little part of the gasket lifted inside of it.
What you guys think it's going on with my car?
2017 Mercedes Benz C43 AMG
90,822 miles
The radiator fan also start sounding crazy high like really loud and vibrating when it pass the 102-103c temp range.
It first had a coolant leak and I fixed it by replacing the radiator, I then replaced the water pump and the auxiliary water pump as well as the radiator fan, but none of that has fixed the issue.
I don't know what to do know, I can't recreate the problem after replacing multiple parts, a mechanic told me the radiator fan wasn't OEM so it's running bad because of that, and somebody else told me that it could be the thermostat because there's a little part of the gasket lifted inside of it.
What you guys think it's going on with my car?
2017 Mercedes Benz C43 AMG
90,822 miles
MBWorld God!
Joined: Dec 2019
Posts: 32,499
Likes: 6,347
So guys, it's been like a month or so that my C43 is showing up to 110-115c in the middle screen when I drive it for more than 30 minutes. When I drive it in Sport or Sport+ it happens a lot faster.
The radiator fan also start sounding crazy high like really loud and vibrating when it pass the 102-103c temp range.
It first had a coolant leak and I fixed it by replacing the radiator, I then replaced the water pump and the auxiliary water pump as well as the radiator fan, but none of that has fixed the issue.
I don't know what to do know, I can't recreate the problem after replacing multiple parts, a mechanic told me the radiator fan wasn't OEM so it's running bad because of that, and somebody else told me that it could be the thermostat because there's a little part of the gasket lifted inside of it.
What you guys think it's going on with my car?
2017 Mercedes Benz C43 AMG
90,822 miles
The radiator fan also start sounding crazy high like really loud and vibrating when it pass the 102-103c temp range.
It first had a coolant leak and I fixed it by replacing the radiator, I then replaced the water pump and the auxiliary water pump as well as the radiator fan, but none of that has fixed the issue.
I don't know what to do know, I can't recreate the problem after replacing multiple parts, a mechanic told me the radiator fan wasn't OEM so it's running bad because of that, and somebody else told me that it could be the thermostat because there's a little part of the gasket lifted inside of it.
What you guys think it's going on with my car?
2017 Mercedes Benz C43 AMG
90,822 miles
Thread Starter
Junior Member
Joined: Apr 2025
Posts: 15
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Yes I did! And the only code I receive is P0018 and it’s about the timing belt inside the engine, sometimes the car takes like 2-4 seconds to turn on but besides that code I don’t have any other. I replaced the fan assembly, the radiator, the water pump and the auxiliary water pump and still the same…
MBWorld God!
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Yes I did! And the only code I receive is P0018 and it’s about the timing belt inside the engine, sometimes the car takes like 2-4 seconds to turn on but besides that code I don’t have any other. I replaced the fan assembly, the radiator, the water pump and the auxiliary water pump and still the same…
Out Of Control!!
Joined: Apr 2019
Posts: 11,993
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
lottery
Yes I did! And the only code I receive is P0018 and it’s about the timing belt inside the engine, sometimes the car takes like 2-4 seconds to turn on but besides that code I don’t have any other. I replaced the fan assembly, the radiator, the water pump and the auxiliary water pump and still the same…
Your M276 Turbo has extreme heat
- new radiator
- new radiator fan
- new water pump
- new AUX pump
- now... active correlation fault.
These engines don't use a timing belt but 3x timing chains instead with 3x hydraulic tensioners. Plus 1 more chain just for oil pump.
You fault calls for a little bit more information:
Q: Does your engine rattle after long starting crank or is it rattle-free?
Repair's gonna be either:
- Cam Sensors
- Intake VVT Gears
- Camshaft plus all the above.
Hopefully engine doesn't rattle else repair bill be stretched longer.
I think you have TWO DISTINCT ISSUES:
- Uncontrolled extreme heat
- Bank-2 timing fault.
The original root cause is limited oiling pressure. At this point it has matured into required repairs.
Try to never keep engine oil past it's prime: 4500.Mi.
Last edited by CaliBenzDriver; Apr 24, 2025 at 09:38 PM.
MBWorld God!
Joined: Dec 2019
Posts: 32,499
Likes: 6,347
Let's try to summarize your issues:
Your M276 Turbo has extreme heat
These engines don't use a timing belt but 3x timing chains instead with 3x hydraulic tensioners. Plus 1 more chain just for oil pump.
You fault calls for a little bit more information:
Q: Does your engine rattle after long starting crank or is it rattle-free?
Repair's gonna be either:
Hopefully engine doesn't rattle else repair bill be stretched longer.
I think you have TWO DISTINCT ISSUES:
The original root cause is limited oiling pressure. At this point it has matured into required repairs.
Try to never keep engine oil past it's prime: 4500.Mi.
Your M276 Turbo has extreme heat
- new radiator
- new radiator fan
- new water pump
- new AUX pump
- now... active correlation fault.
These engines don't use a timing belt but 3x timing chains instead with 3x hydraulic tensioners. Plus 1 more chain just for oil pump.
You fault calls for a little bit more information:
Q: Does your engine rattle after long starting crank or is it rattle-free?
Repair's gonna be either:
- Cam Sensors
- Intake VVT Gears
- Camshaft plus all the above.
Hopefully engine doesn't rattle else repair bill be stretched longer.
I think you have TWO DISTINCT ISSUES:
- Uncontrolled extreme heat
- Bank-2 timing fault.
The original root cause is limited oiling pressure. At this point it has matured into required repairs.
Try to never keep engine oil past it's prime: 4500.Mi.
Thread Starter
Junior Member
Joined: Apr 2025
Posts: 15
Likes: 0
Let's try to summarize your issues:
Your M276 Turbo has extreme heat
These engines don't use a timing belt but 3x timing chains instead with 3x hydraulic tensioners. Plus 1 more chain just for oil pump.
You fault calls for a little bit more information:
Q: Does your engine rattle after long starting crank or is it rattle-free?
Repair's gonna be either:
Hopefully engine doesn't rattle else repair bill be stretched longer.
I think you have TWO DISTINCT ISSUES:
The original root cause is limited oiling pressure. At this point it has matured into required repairs.
Try to never keep engine oil past it's prime: 4500.Mi.
[img alt="rolleyes.gif"]blob:https://mbworld.org/ef438374-45e2-4424-806e-4319436fc210[/img]
Your M276 Turbo has extreme heat
- new radiator
- new radiator fan
- new water pump
- new AUX pump
- now... active correlation fault.
These engines don't use a timing belt but 3x timing chains instead with 3x hydraulic tensioners. Plus 1 more chain just for oil pump.
You fault calls for a little bit more information:
Q: Does your engine rattle after long starting crank or is it rattle-free?
Repair's gonna be either:
- Cam Sensors
- Intake VVT Gears
- Camshaft plus all the above.
Hopefully engine doesn't rattle else repair bill be stretched longer.
I think you have TWO DISTINCT ISSUES:
- Uncontrolled extreme heat
- Bank-2 timing fault.
The original root cause is limited oiling pressure. At this point it has matured into required repairs.
Try to never keep engine oil past it's prime: 4500.Mi.
[img alt="rolleyes.gif"]blob:https://mbworld.org/ef438374-45e2-4424-806e-4319436fc210[/img]
So now I have changed the thermostat and the radiator fan for the OEM ones, so for now I have replaced:
- Radiator
- Radiator Fan Assembly
- Thermostat
- Water Pump
- Aux Water Pump
- Lower Coolant Hose
- Coolant Hose
There’s no rattle, I only listen to a little rattle few times when it’s warming up and that’s only a few times and only takes 5-10 seconds before it goes away.
Now, moving onto the codes, I did received 2 codes instead of 1, I forgot to add the second one to the post but here we go:
- P0018
- P0456
Before doing the part replacements I stated first (like a month ago or so) I was receiving a 3rd code with this numeration along with the P0456:
- P0442
But it went away when I replaced either the radiator or the radiator fan I'm not sure but I do know that the P0442 and P0456 came in together as I only had the P0018 before.
Aftermath:
After replacing all these parts, the car now takes a little more longer to get hot, it maintains temps a little more but still surpass the 100c and keeps going up until it reaches 103c-104c, where the fan starts sounding a lot more, from there, if I keep driving or stay idle in traffic depending on the conditions it would go up and down (yesterday it went up to 111c at 2:33pm in the Florida weather).
When I stay idle for long periods, for example parked, it does not overheat, it will stay on the 90c-97c temp range with no overheating issues at all, everything happens when I’m driving or constant motion.
Here's some videos attached of how it acts from turning it on, driving it from operational temperature to the top temperature.
Last edited by Daykol; Apr 25, 2025 at 08:17 PM.
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Out Of Control!!
Joined: Apr 2019
Posts: 11,993
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
heat soaked by idling
You are making good progress using genuine parts.
When I stay idle for long periods, for example parked, it does not overheat, it will stay on the 90c-97c temp range with no overheating issues at all...
Everything happens when I’m driving or constant motion.
Let me try to help you understand something about heat here...
Realize that when idle engine heat is not circulated. Fam cools the radiator but heat is not pumped to radiator.
When your gauges show your temps are fine, the accumulated engine heat is baking all its plastics.
Then you noticed that when you start driving... heat temp shoots up wild.
Thats when RPM begins to circulate heat out through burning oil exchanger towards radiator.
The easiest thing to do is don't idle this engine. Heat removal is a slow process of equilibrium. Once its hot engine stays hot because.... read this:
FAN DOES NOT COOL THE ENGINE.
IT ONLY COOLS THE RADIATOR.
Engine accumulates unremoved heat.
Fan runs in winter or summer without ability cooling the engine.
> Towards Normal Heat:
-- A great step in the right direction is to spray cool pistons while driving - This can NOT be done at 700 Rpm idle!!
-- Another great step is reduce hot blow-by gases steaming the inside of crankcase.
Results can be had only above idle EV is what an deliver what you need.
When I stay idle for long periods, for example parked, it does not overheat, it will stay on the 90c-97c temp range with no overheating issues at all...
Everything happens when I’m driving or constant motion.
Let me try to help you understand something about heat here...
Realize that when idle engine heat is not circulated. Fam cools the radiator but heat is not pumped to radiator.
When your gauges show your temps are fine, the accumulated engine heat is baking all its plastics.
Then you noticed that when you start driving... heat temp shoots up wild.
Thats when RPM begins to circulate heat out through burning oil exchanger towards radiator.
The easiest thing to do is don't idle this engine. Heat removal is a slow process of equilibrium. Once its hot engine stays hot because.... read this:
FAN DOES NOT COOL THE ENGINE.
IT ONLY COOLS THE RADIATOR.
Engine accumulates unremoved heat.
Fan runs in winter or summer without ability cooling the engine.
> Towards Normal Heat:
-- A great step in the right direction is to spray cool pistons while driving - This can NOT be done at 700 Rpm idle!!
-- Another great step is reduce hot blow-by gases steaming the inside of crankcase.
Results can be had only above idle EV is what an deliver what you need.
Last edited by CaliBenzDriver; Apr 26, 2025 at 12:43 AM.
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Thread Starter
Junior Member
Joined: Apr 2025
Posts: 15
Likes: 0
Thread Starter
Junior Member
Joined: Apr 2025
Posts: 15
Likes: 0
You are making good progress using genuine parts.
When I stay idle for long periods, for example parked, it does not overheat, it will stay on the 90c-97c temp range with no overheating issues at all...
Everything happens when I’m driving or constant motion.
Let me try to help you understand something about heat here...
Realize that when idle engine heat is not circulated. Fam cools the radiator but heat is not pumped to radiator.
When your gauges show your temps are fine, the accumulated engine heat is baking all its plastics.
Then you noticed that when you start driving... heat temp shoots up wild.
Thats when RPM begins to circulate heat out through burning oil exchanger towards radiator.
The easiest thing to do is don't idle this engine. Heat removal is a slow process of equilibrium. Once its hot engine stays hot because.... read this:
FAN DOES NOT COOL THE ENGINE.
IT ONLY COOLS THE RADIATOR.
Engine accumulates unremoved heat.
Fan runs in winter or summer without ability cooling the engine.
> Towards Normal Heat:
-- A great step in the right direction is to spray cool pistons while driving - This can NOT be done at 700 Rpm idle!!
-- Another great step is reduce hot blow-by gases steaming the inside of crankcase.
Results can be had only above idle EV is what an deliver what you need.
When I stay idle for long periods, for example parked, it does not overheat, it will stay on the 90c-97c temp range with no overheating issues at all...
Everything happens when I’m driving or constant motion.
Let me try to help you understand something about heat here...
Realize that when idle engine heat is not circulated. Fam cools the radiator but heat is not pumped to radiator.
When your gauges show your temps are fine, the accumulated engine heat is baking all its plastics.
Then you noticed that when you start driving... heat temp shoots up wild.
Thats when RPM begins to circulate heat out through burning oil exchanger towards radiator.
The easiest thing to do is don't idle this engine. Heat removal is a slow process of equilibrium. Once its hot engine stays hot because.... read this:
FAN DOES NOT COOL THE ENGINE.
IT ONLY COOLS THE RADIATOR.
Engine accumulates unremoved heat.
Fan runs in winter or summer without ability cooling the engine.
> Towards Normal Heat:
-- A great step in the right direction is to spray cool pistons while driving - This can NOT be done at 700 Rpm idle!!
-- Another great step is reduce hot blow-by gases steaming the inside of crankcase.
Results can be had only above idle EV is what an deliver what you need.
Out Of Control!!
Joined: Apr 2019
Posts: 11,993
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
tire shop MB service
I didn’t knew this car had 2 coolant reservoirs! Apparently that was the problem the whole time!
There was a reservoir in the middle of the engine on a white bottle, I went to tire plus and they said it was empty and I never filled that up!
Only the one reservoir in the left!
That could be the cause?
There was a reservoir in the middle of the engine on a white bottle, I went to tire plus and they said it was empty and I never filled that up!
Only the one reservoir in the left!
That could be the cause?
MB engine use specific coolant chemistry... not "standard green".
Last edited by CaliBenzDriver; Apr 26, 2025 at 07:43 PM.
Thread Starter
Junior Member
Joined: Apr 2025
Posts: 15
Likes: 0
I went to Tire Plus today and apparently I didn’t understood what they said but they did told me that there was a empty reservoir and that was the reason of the overheating! Not sure but the car is driving fine as right now no overheating at all let’s see wassup
Out Of Control!!
Joined: Apr 2019
Posts: 11,993
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
leaking intake cooler
Now you can keep an eye on the center reservoir to know how fast it drains empty. That's a usual leak.
Besides, none of that circuit cools engine block.
Thread Starter
Junior Member
Joined: Apr 2025
Posts: 15
Likes: 0
Because they said it’s fixed and it look fixed to me
if that’s the case then what reservoir did they filled? If it wasn’t the coolant one? Lol
i found something online saying that is the turbo coolant
Out Of Control!!
Joined: Apr 2019
Posts: 11,993
Likes: 6,827
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
Your engine use two separate circuits.
Idling a long time, stores extreme heat regardless of all coolant circuits being full.
