SLK noise when parked :-/

micktick · 01-31-2008

Hi all

I have just picked up my 2006 SLK280 and love it but have a question.

When i park it up, lock it etc and walk away for a considerable time after it makes what i can only describe as a loudish pump/whir sound for a couple of seconds then a gap and then again and so on. It really is quite loud, is this normal ?

Thanks.

MarkR171 · 01-31-2008

Maybe the A/C? Usually hear it for a few second after shutting the engine off.

mtiede · 01-31-2008

Do you live in a hot climate? Perhaps it is an electric cooling fan operating? I haven't even looked under the hood to see if it has one, but I think cars do that nowadays.

**DansSlk** · 01-31-2008

That could be a few things, the suction fan should not operate like that when its cooling so unless you have AC rest running i would call it not normal thats not to say its bad.

What I'd recommend is pop the hood when you park up and have it opened up before you lock the car then give everything under it a good inspection and a listen.

Anything directly connected to the engine should not be operating, it has a few pumps and things that sound like your noise.

The suction fan can operate at any time, the AC intake fan should not operate unless REST is active

And finally the duovalves and the electric coolant pump should not operate unless REST is active.

MarkR171 · 01-31-2008

About that Dan, what exactly does "A/C REST" do?

Edit: Just searched around in google, guess I'll be turning that off when I head home from work. No use for residual heat in Hawaii

micktick · 01-31-2008

thanks for the replies

the sound goes on for at least 30 minutes maybe an hour, not really had the chance to look too depply into it.

the weather in the uk is pretty cold at present, around 8 degrees c last few days

i have maybe mislead on the type of sound, it's more whurrr than whoosh if that makes any sense ? it's a more electical or mechanical sound than a flowing air or liquid sound more of a buzz and like i say its loud, i was about 25 ft away and it was as clear as day !

i did a quick look at the time and on first ( read less than great inspection ! ) it sounded like it was on the right of the engine bay mouldings by the lump of metal with metal pipes coming from it :-/

what is this "rest" thing you are talking about ? sorry like i say this car is totally new to me as is mercedes.

thanks

MarkR171 · 01-31-2008

The A/C Rest is here:

I believe it allows the car to keep the heater running with the engine off for a short time. This is so you can park the car, go and do whatever it is you need to do then return to a car that's still warm inside.

I don't know for sure as I live in Hawaii where the heater is never used anyway...

micktick · 01-31-2008

Quote:

Originally Posted by MarkR171

The A/C Rest is here:

I believe it allows the car to keep the heater running with the engine off for a short time. This is so you can park the car, go and do whatever it is you need to do then return to a car that's still warm inside.

I don't know for sure as I live in Hawaii where the heater is never used anyway...

i have the climate control rather than air con, does the climate have this feature ?

thanks

Zut · 01-31-2008

Quote:

Originally Posted by MarkR171

I believe it allows the car to keep the heater running with the engine off for a short time. This is so you can park the car, go and do whatever it is you need to do then return to a car that's still warm inside.

I don't know for sure as I live in Hawaii where the heater is never used anyway...

That is exactly what it does (for 30 minutes). I used it for the first time last week and it works very well. I believe it also keeps the cabin cool in the summer but I never tried it.

**DansSlk** · 01-31-2008

OK the AC Rest on both the AAC (Pictured) and the C-AAC (Not pictured but has the same function - button is center of right ring) operates the fan at the lowest speed setting for 30 minutes or until the battery voltage drops below safe, if the car's interior is cooler than the last selected settings on the unit and the coolant temperature is higher the electric coolant pump is operated to heat the interior, if the interior is hotter than the last selected temp the fan operates without coolant assist so it pumps ambient air into the cabin.

micktick, Do you have or can you get a pic of the area in question i know its very hard to describe components when you don't know the exact function of them its just very hard to even imagine what it could be from my point of view.

Unless its a fan or a pump you should not be able to hear it from that distance.

micktick · 02-01-2008

I've found the a/c rest feature and activated it, the sound is differant and it's a more constant noise than the one i'm on about, but thanks i didn't know about it

I've also discovered the sound starts after a time, wasn't doing it after 10 or 15 minutes but was happening after 40 mins and is still going now after 1h25m !

I've taken a couple of pics with the area it's making the noise from, cant say it's one thing or another but it is in the area marked.

I've also taken a video with the sound on, you have to turn it up quite a bit to hear as the camera microphone sucks and it's really a lot louder than it sounds on the clip, you can hear it 20ft away easily with the bonnet down.

http://homepage.ntlworld.com/michael.johnson1951/R0010268.AVI

Thanks

Ikarus · 02-01-2008

I've heard this sound on my 2006 280 (same model and year, coincidence?) on two occasions now and have been meaning to ask about it here. In my case, the engine wasn't off but rather idling after being warmed up from driving. It's pretty loud indeed, and impossible to miss.

Thunder · 02-01-2008

What about something that keeps the engine getting cold after a big use that made it hot ?

**DansSlk** · 02-01-2008

OK so either the ESP pump or what looks like the EGR valve but I'd have to check that for the 280 since my memory is a tad grey about it.

Can't understand why either would be doing anything with the engine off, they shouldn't even have power to be honest.

mtiede · 02-01-2008

When trying to pinpoint a noise like that, you can use a biggish screwdriver and (being careful not to short out something electrical, or sticking in something that may move, or having your tie or a piece of clothing that may become entangled in something is or could move) put one end to your ear and touch the other end to where you thing the noise is coming from. Usually you will clearly be able to tell what exactly the noise is coming from.

micktick · 02-04-2008

Thanks for the replies, as no one really knows i've booked it in back at Mercedes to have a look, whatever it is should be covered as i've only had it just over a week ! Will post back when i know the answer.

Cheers

Ikarus · 02-05-2008

I just asked on slkworld.de whether anyone knows about this. I'll report back if there's anything.

01-31-2008	#1 (permalink)
micktick SLK World Junior Member Join Date: Jan 2008 Location: Staffordshire Vehicle: 2006 SLK280 Posts: 6 Country: Thanks: 0 Thanked 0 Times in 0 Posts	SLK noise when parked :-/ Hi all I have just picked up my 2006 SLK280 and love it but have a question. When i park it up, lock it etc and walk away for a considerable time after it makes what i can only describe as a loudish pump/whir sound for a couple of seconds then a gap and then again and so on. It really is quite loud, is this normal ? Thanks.
	http://www.slkworld.com/

01-31-2008	#4 (permalink)
DansSlk Super Moderator Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,461 Country: Thanks: 85 Thanked 145 Times in 116 Posts	That could be a few things, the suction fan should not operate like that when its cooling so unless you have AC rest running i would call it not normal thats not to say its bad. What I'd recommend is pop the hood when you park up and have it opened up before you lock the car then give everything under it a good inspection and a listen. Anything directly connected to the engine should not be operating, it has a few pumps and things that sound like your noise. The suction fan can operate at any time, the AC intake fan should not operate unless REST is active And finally the duovalves and the electric coolant pump should not operate unless REST is active. __________________ One thing you will learn with German cars - If it's simple it ain't happening.

01-31-2008	#10 (permalink)
DansSlk Super Moderator Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,461 Country: Thanks: 85 Thanked 145 Times in 116 Posts	OK the AC Rest on both the AAC (Pictured) and the C-AAC (Not pictured but has the same function - button is center of right ring) operates the fan at the lowest speed setting for 30 minutes or until the battery voltage drops below safe, if the car's interior is cooler than the last selected settings on the unit and the coolant temperature is higher the electric coolant pump is operated to heat the interior, if the interior is hotter than the last selected temp the fan operates without coolant assist so it pumps ambient air into the cabin. micktick, Do you have or can you get a pic of the area in question i know its very hard to describe components when you don't know the exact function of them its just very hard to even imagine what it could be from my point of view. Unless its a fan or a pump you should not be able to hear it from that distance. __________________ One thing you will learn with German cars - If it's simple it ain't happening.

02-01-2008	#14 (permalink)
DansSlk Super Moderator Join Date: Jun 2006 Location: Wales Vehicle: 05 B55S (Brabus 6.1 S) Posts: 6,461 Country: Thanks: 85 Thanked 145 Times in 116 Posts	OK so either the ESP pump or what looks like the EGR valve but I'd have to check that for the 280 since my memory is a tad grey about it. Can't understand why either would be doing anything with the engine off, they shouldn't even have power to be honest. __________________ One thing you will learn with German cars - If it's simple it ain't happening.

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01-31-2008	#2 (permalink)
MarkR171 Elite SLK World Member Join Date: Jun 2007 Location: Honolulu, Hawaii Vehicle: '07 SLK280 Posts: 210 Country: Thanks: 0 Thanked 0 Times in 0 Posts	Maybe the A/C? Usually hear it for a few second after shutting the engine off.

01-31-2008	#3 (permalink)
mtiede Founding Member #7 Join Date: Jun 2006 Location: Western New York Vehicle: 2006 SLK 350 Posts: 1,419 Thanks: 71 Thanked 40 Times in 30 Posts	Do you live in a hot climate? Perhaps it is an electric cooling fan operating? I haven't even looked under the hood to see if it has one, but I think cars do that nowadays.

01-31-2008	#5 (permalink)
MarkR171 Elite SLK World Member Join Date: Jun 2007 Location: Honolulu, Hawaii Vehicle: '07 SLK280 Posts: 210 Country: Thanks: 0 Thanked 0 Times in 0 Posts	About that Dan, what exactly does "A/C REST" do? Edit: Just searched around in google, guess I'll be turning that off when I head home from work. No use for residual heat in Hawaii

01-31-2008	#6 (permalink)
micktick SLK World Junior Member Join Date: Jan 2008 Location: Staffordshire Vehicle: 2006 SLK280 Posts: 6 Country: Thanks: 0 Thanked 0 Times in 0 Posts	thanks for the replies the sound goes on for at least 30 minutes maybe an hour, not really had the chance to look too depply into it. the weather in the uk is pretty cold at present, around 8 degrees c last few days i have maybe mislead on the type of sound, it's more whurrr than whoosh if that makes any sense ? it's a more electical or mechanical sound than a flowing air or liquid sound more of a buzz and like i say its loud, i was about 25 ft away and it was as clear as day ! i did a quick look at the time and on first ( read less than great inspection ! ) it sounded like it was on the right of the engine bay mouldings by the lump of metal with metal pipes coming from it :-/ what is this "rest" thing you are talking about ? sorry like i say this car is totally new to me as is mercedes. thanks

01-31-2008	#7 (permalink)
MarkR171 Elite SLK World Member Join Date: Jun 2007 Location: Honolulu, Hawaii Vehicle: '07 SLK280 Posts: 210 Country: Thanks: 0 Thanked 0 Times in 0 Posts	The A/C Rest is here: I believe it allows the car to keep the heater running with the engine off for a short time. This is so you can park the car, go and do whatever it is you need to do then return to a car that's still warm inside. I don't know for sure as I live in Hawaii where the heater is never used anyway...

02-01-2008	#11 (permalink)
micktick SLK World Junior Member Join Date: Jan 2008 Location: Staffordshire Vehicle: 2006 SLK280 Posts: 6 Country: Thanks: 0 Thanked 0 Times in 0 Posts	I've found the a/c rest feature and activated it, the sound is differant and it's a more constant noise than the one i'm on about, but thanks i didn't know about it I've also discovered the sound starts after a time, wasn't doing it after 10 or 15 minutes but was happening after 40 mins and is still going now after 1h25m ! I've taken a couple of pics with the area it's making the noise from, cant say it's one thing or another but it is in the area marked. I've also taken a video with the sound on, you have to turn it up quite a bit to hear as the camera microphone sucks and it's really a lot louder than it sounds on the clip, you can hear it 20ft away easily with the bonnet down. http://homepage.ntlworld.com/michael.johnson1951/R0010268.AVI Thanks

02-01-2008	#12 (permalink)
Ikarus Elite SLK World Member Join Date: Jul 2006 Location: NorCal Vehicle: 2006 SLK 280 w. 6M Other Toys: 2000 New Beetle GLS w. 5M Posts: 577 Country: Thanks: 20 Thanked 34 Times in 17 Posts	I've heard this sound on my 2006 280 (same model and year, coincidence?) on two occasions now and have been meaning to ask about it here. In my case, the engine wasn't off but rather idling after being warmed up from driving. It's pretty loud indeed, and impossible to miss.

02-01-2008	#13 (permalink)
Thunder SLK World Member Join Date: Jan 2008 Location: Modena Posts: 19 Country: Thanks: 0 Thanked 0 Times in 0 Posts	What about something that keeps the engine getting cold after a big use that made it hot ?

02-01-2008	#15 (permalink)
mtiede Founding Member #7 Join Date: Jun 2006 Location: Western New York Vehicle: 2006 SLK 350 Posts: 1,419 Thanks: 71 Thanked 40 Times in 30 Posts	When trying to pinpoint a noise like that, you can use a biggish screwdriver and (being careful not to short out something electrical, or sticking in something that may move, or having your tie or a piece of clothing that may become entangled in something is or could move) put one end to your ear and touch the other end to where you thing the noise is coming from. Usually you will clearly be able to tell what exactly the noise is coming from.

02-04-2008	#16 (permalink)
micktick SLK World Junior Member Join Date: Jan 2008 Location: Staffordshire Vehicle: 2006 SLK280 Posts: 6 Country: Thanks: 0 Thanked 0 Times in 0 Posts	Thanks for the replies, as no one really knows i've booked it in back at Mercedes to have a look, whatever it is should be covered as i've only had it just over a week ! Will post back when i know the answer. Cheers

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02-05-2008	#17 (permalink)
Ikarus Elite SLK World Member Join Date: Jul 2006 Location: NorCal Vehicle: 2006 SLK 280 w. 6M Other Toys: 2000 New Beetle GLS w. 5M Posts: 577 Country: Thanks: 20 Thanked 34 Times in 17 Posts	I just asked on slkworld.de whether anyone knows about this. I'll report back if there's anything.