Whirring noise when car is off and battery died if car is not driven for 1 day

[bengwie]

Hi all, Starting last week, I have this problem on my 02' C320. The car was driven on weekdays to work without any problem, but if it is not driven on Saturday, then battery died on Sunday. About 6 months ago, we had the battery draining problem, but I have spent a lot of money to replace the modules here (including the faulty passenger modules) and there to make sure the problems never come back, but here we go again. Tonight (on Saturday night), we just came home and this car was not driven again on entire Saturday, and we heard a very weird whirring noise coming from right underneath the battery side. I am wondering what it is, and when we try to open the door, the battery is already dead. Does anyone of you know what happens? Any help will be appreciated.

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[Dingleberry]

was the noise with the car off?

If so, secondary air pump RELAY is broken ($20). Sometimes it can take the secondary air pump itself out too ($500, ouch)

[bengwie]

Yes, that's with the car off for 24+ hours. So that broken air pump relay drains down the battery?

Originally Posted by Dingleberry

was the noise with the car off?

If so, secondary air pump RELAY is broken ($20). Sometimes it can take the secondary air pump itself out too ($500, ouch)

[Dingleberry]

Originally Posted by bengwie

Yes, that's with the car off for 24+ hours. So that broken air pump relay drains down the battery?

Yes. There's also a good chance that the air pump is fried too, since you let it scream away for 24+ hours. The secondary air pump is only supposed to be on for 30 seconds during cold starts, when the relay fails, the air pump stays on permanently up until it turns into a nukuler bomb and explodes creating a break in the space/time continuum (but this is rare, usually they just stop working after over-running)

May the force be with you.

[bengwie]

It didn't scream when we turned off the car on Friday evening, but we found it screaming on Saturday night and the battery was already dead.

Originally Posted by Dingleberry

Yes. There's also a good chance that the air pump is fried too, since you let it scream away for 24+ hours. The secondary air pump is only supposed to be on for 30 seconds during cold starts, when the relay fails, the air pump stays on permanently up until it turns into a nukuler bomb and explodes creating a break in the space/time continuum (but this is rare, usually they just stop working after over-running)

May the force be with you.

[HT84]

That whirring noise! i had that happen once about 7 weeks ago. Ive been jumping my car on and off. Been through 7 batteries 1 alternator. My car dies if i dont start it within 20hrs or so. Did you find the problem yet? I cant afford to take my 2002 c320 to the dealership right now tough times, but i would like to drive my vehicle without having to pop the hood, remove the filter, pull a big truck into the garage, wait for it to charge, start, pull truck out put cable back into trunk, wash my hands then take off.

[Glyn M Ruck]

See TemjinX2's seat control module modification - cheap & easy.

Otherwise follow Dingleberry's (Mr imagination in overdrive ) secondary air pump advice.

[TemjinX2]

if you replaced the seat modules already. Try pulling the fuse for the sun roof. Other sources of battery drainage is the over head module that powers the sun roof and the fan that cools the command nav system.

There's a defect in some command systems where the fan keeps running after the car is off. If possible see if you can get the battery charged at autozone or something. A few members have blown there rear SAMs by jumping the car too much.

if you don't want to trouble shoot, you can just detach the negative terminal on the battery when your not going to drive it the next day.

[samaritrey]

+1 on the nav my fan never goes off on it. but i have left the car over two weeks parked and came back and it started right up. so i just ignore it that is why we have a Mercedes and 1-800-FOR-MERCEDES.

[Glyn M Ruck]

Originally Posted by TemjinX2

if you replaced the seat modules already. Try pulling the fuse for the sun roof. Other sources of battery drainage is the over head module that powers the sun roof and the fan that cools the command nav system.

There's a defect in some command systems where the fan keeps running after the car is off. If possible see if you can get the battery charged at autozone or something. A few members have blown there rear SAMs by jumping the car too much.

if you don't want to trouble shoot, you can just detach the negative terminal on the battery when your not going to drive it the next day.

Mike - how long do seat control modules last? Possible that new ones have gone faulty?

[TemjinX2]

Originally Posted by Glyn M Ruck

Mike - how long do seat control modules last? Possible that new ones have gone faulty?

one was the original, the other was new with the 203 part number and it still went bad after about a yr. I'm convinced all the 203 parts are crap. Mercedes seems to agree, since there replacing all the 203 parts with 211 ones.

All the new seat control modules use 211 part number. The accelerator pedal i just replaced uses a 211 part number as well.

[samaritrey]

Originally Posted by TemjinX2

one was the original, the other was new with the 203 part number and it still went bad after about a yr. I'm convinced all the 203 parts are crap. Mercedes seems to agree, since there replacing all the 203 parts with 211 ones.

All the new seat control modules use 211 part number. The accelerator pedal i just replaced uses a 211 part number as well.

+1 on that. when i got my car i started reading about all the problems with the seat controllers and got scared. i then puled both out and saw the w211 pn and was like wtf. the next time i was in the dealer i asked and they told me that they had way to many problems with the w203 pn ones so they swiched companies and changed the 203 to 211 pn so that they could tell if the car had the old or new part.