Got a wirling sound
#1
Got a wirling sound
2008 c300 it's killing me when I press on the gas low rpm it makes this wirling sound idk if I can hear it from the outside but it's not the steering positive,thought it would go away nothing yet owned it for 6 months now
Don't know what to do someone help what could it be??
Don't know what to do someone help what could it be??
#2
Super Member
That could be the air intake you are hearing. Low speed so there is no wind and you hear it more.
Last edited by w204_Generic; 02-14-2014 at 11:37 PM.
#3
Super Moderator
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It could be the transmission oil pump. Can you hear it stationary in neutral or park? It could also be the poly V belt tensioner or idlers.
#4
#5
When I rev it it gets wirly on drive neutral and park. thanks for the idea I've got an appointment for a software issue gonna take it to mercedez see what they think.
#6
Member
Similarly, I noticed that when using the suggested gear ranges of D1 and D2 the engine exhaust note sounded much more high pitched and whiny as opposed to its usually deep robust sound. Is this potentially also the transmission oil pump/poly V belt/tensioner/idlers?
#7
Super Moderator
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It sounds as though it could be the transmission oil pump you are hearing. It is a little variable unit to unit & is normal. Benz redesigned & changed to an aluminium pump to reduce noise but it's still there.
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#9
Senior Member
I hear it in lower gears, 1 and 2. Whenever I drive through my university parking structure it is very noticeable. Like Glyn said, I assume it is normal. I feel like manual transmission and more sport oriented cars such as BMW don't have the same noise whine.
#10
Yea it gets to me a lot. gotta blast the radio to ignore it lol
#12
Super Moderator
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The transmission pump does make a noise in Park. It runs continuously at input shaft speed with engine running.
#14
Super Moderator
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On some older 722.9 transmissions the pump actually makes the most noise on start up in Park. You get a bit of a roar out of the pump until pressure normalises in the transmission & then it quietens down.
#15
#16
Super Moderator
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Even the old 722.6 5 speed did it. It's just a Benz noise you get used to. If it gets really loud it can be sign of a failing torque converter but I mean really loud.
#20
I have noticed a slight hum of the pump at low speeds when there is not much road noise. Immediately knew it was transmission as it has a very distinct sound.
Glad to hear from Glyn that this hum is likely normal is a known characteristic of this transmission. I am still getting acclimated to the feel and sounds of this car as I have only had it a couple weeks.
Glad to hear from Glyn that this hum is likely normal is a known characteristic of this transmission. I am still getting acclimated to the feel and sounds of this car as I have only had it a couple weeks.
#21
I have noticed a slight hum of the pump at low speeds when there is not much road noise. Immediately knew it was transmission as it has a very distinct sound. Glad to hear from Glyn that this hum is likely normal is a known characteristic of this transmission. I am still getting acclimated to the feel and sounds of this car as I have only had it a couple weeks.
Yea I'm trying to get used to it. Blast the radio it helps lol
#22
Super Moderator
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This has been a characteristic of Benz cars for a long time.
722.9 oil pump
722.9 oil pump
![](https://mbworld.org/forums/attachments/off-topic/212511d1308408119-hypermiling-bad-transmission-722.6-722.9-oil-pump.jpg)
#24
#25
Sorry to rehash an old topic...
but does the whining sound... is that like an electric motor from a R/C car? I picked up 2012 C250, and when I am starting off, I can definitely hear that sound. Was curious if this was the sound everyone else heard.
Thank you
but does the whining sound... is that like an electric motor from a R/C car? I picked up 2012 C250, and when I am starting off, I can definitely hear that sound. Was curious if this was the sound everyone else heard.
Thank you