what keep running after engine is off
Thread Starter
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Joined: Apr 2006
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From: Barrington IL
2015 E 250, 1999 BMW M Roadster, 1939 International Harvester, 2023 GLC
what keep running after engine is off
my 2015 E250 Blutec often has something running like a small motor after shutting off. This runs for minutes or an hour. Anyone know what this is?
Thread Starter
Senior Member
Joined: Apr 2006
Posts: 438
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From: Barrington IL
2015 E 250, 1999 BMW M Roadster, 1939 International Harvester, 2023 GLC
indeed I have done this but with so many covers it is hard to pin point. I was thinking a circulation pump of some type. Does not happen every time. It's not very loud I only hear it in my garage after driving and not each and every time.
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Yes, but the fan does not sound like a pump. It is very quiet from outside the car and is more like a gentle humming.
These cars are just noisy all the time and seem to be working 24 hours a day. No wonder our batteries are always in need of replacement.
These cars are just noisy all the time and seem to be working 24 hours a day. No wonder our batteries are always in need of replacement.
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Thread Starter
Senior Member
Joined: Apr 2006
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From: Barrington IL
2015 E 250, 1999 BMW M Roadster, 1939 International Harvester, 2023 GLC
I expect it is the fans as suggested. Funny sounding buzzy fan that is just moving air but it's coming from both headlight modules.
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From: Barrington IL
2015 E 250, 1999 BMW M Roadster, 1939 International Harvester, 2023 GLC
I've wonder if this heat helps with snow & Ice? Winter snow and ice can really cover up both the headlights and tail lights even after clearing. In the ole days you could count on the heat from the filaments to keep ice from forming. No doubt they must have thought this through with LED's front & rear.
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I believe you are correct and part of the function of these fans is to move warm air into the front of the light housing for the specific purpose of melting snow/ice. I did read that somewhere quite a while ago. I do not have LED headlights, so I do not follow everything associated with that technology. I use LED technology in my architectural practice extensively, so I am familiar with the lamps capabilities and shortcomings.
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I've wonder if this heat helps with snow & Ice? Winter snow and ice can really cover up both the headlights and tail lights even after clearing. In the ole days you could count on the heat from the filaments to keep ice from forming. No doubt they must have thought this through with LED's front & rear.
As headlight technology gets more and more efficient, they produce less heat and more light. The good old halogen bulb heats up the headlight nicely to melt snow and ice. Xenon gives out less heat than halogen at the lens and LED is almost cool to the touch when it is on. The whole idea of a cooling fan for the rectifier is to remove the heat from the electronics, it would not make much sense to blow the hot air into a closed headlight housing assembly.
