Cooling system pressure increase when ac is on
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Joined: Sep 2017
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Ml 350 2005
Cooling system pressure increase when ac is on
I have a 2005 ML 350. In the past 2 months ( summer time in the gulf , outside temp approx 40 celsius daytime) i faced consecutive problems in my cooling system parts. It started by leaking of coolent from cap of coolant vontainer after a long rinning in a hot day. I changed it but after few days i started seeing leak in radiator so i changed. In few days coolent started decreasong again and this time it was the small secondary coolant pump. I changed it but in 2 days the oil was mixed with coolant in the coolant container and it was the oil cooler. I changed it and all was fine for few days with the exception of the engine temperature rising to approx 100c when ac is on. Yesterday when i was waiting for approx 20 min stationary in hot weather and ac on, the cap got damaged and coolant leaked from cap. I will buy new cap tomorrow but i dont know when this will end. I fix it at private garages and not at the mercedes agency.
Any ideas. I guess that there is an increase in the coolant pressure when the ac is on in hot weather.
Any ideas. I guess that there is an increase in the coolant pressure when the ac is on in hot weather.
Thread Starter
Newbie
Joined: Sep 2017
Posts: 4
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Ml 350 2005
Very true
Thank you. It was the problem. I cant inagine how mechanics changed various parts in the cooling system and never checked the fan.
2 days ago, and after reading one thread in this forum, where they mentioned the fan malfunction as one reason for overheating, i watched the fan in few instances when the engine temp was rising, and it was obvious that the fan was not working. I took it to an electrician and specifically asked him to check the cutout. The cutout was in a good shape but the problem was with a damaged relay connection in the fuse box ( the plastic melted below it so it was not easily pointed).
2 days ago, and after reading one thread in this forum, where they mentioned the fan malfunction as one reason for overheating, i watched the fan in few instances when the engine temp was rising, and it was obvious that the fan was not working. I took it to an electrician and specifically asked him to check the cutout. The cutout was in a good shape but the problem was with a damaged relay connection in the fuse box ( the plastic melted below it so it was not easily pointed).
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'99 and '05 E55 AMG
Thank you. It was the problem. I cant inagine how mechanics changed various parts in the cooling system and never checked the fan.
2 days ago, and after reading one thread in this forum, where they mentioned the fan malfunction as one reason for overheating, i watched the fan in few instances when the engine temp was rising, and it was obvious that the fan was not working. I took it to an electrician and specifically asked him to check the cutout. The cutout was in a good shape but the problem was with a damaged relay connection in the fuse box ( the plastic melted below it so it was not easily pointed).
2 days ago, and after reading one thread in this forum, where they mentioned the fan malfunction as one reason for overheating, i watched the fan in few instances when the engine temp was rising, and it was obvious that the fan was not working. I took it to an electrician and specifically asked him to check the cutout. The cutout was in a good shape but the problem was with a damaged relay connection in the fuse box ( the plastic melted below it so it was not easily pointed).
