Finally I found an answer
For future references this a conversation on one of the US forums .... nothing to do with abc
Quote:
Originally Posted by GT-ER
IT'S NOT!
When you turn your car on in the mornings you hear this power steering like whine that mostly goes away in about a minute or so. The general consensus in this forum is that the whine came from the secondary air injection pump.
Well, today I removed my SAIP and the whine is still there as it was before and would still quiet down after a minute or so. Shocked at my findings I was determined to find out where this noise came from. Since it sounds like a power steering whine, I checked the power steering pump. No go.
So I sat down thinking, what could sound like a power steering pump? It came to my mind that a transmission pump is actually pretty identical to a power steering pump in design and so I placed close attention to my transmission.
THE NOISE IS COMING FROM THE TRANSMISSION PUMP which is located near the torque converter. Granted, I've heard this same noise on every single E55 I've heard start up so I can only assume it's normal.
Anyways, hope this helps you guys sleep better. I know I will.
BTW- I'm guessing the SAIP weighs about 5lbs. Less than I expected but a lighter car is a lighter car...lol
Hi man!
You ask me to post our conversation (my part of it)...here is it:
...i think that you are wrong, because our cold start (and sometimes even hot) whine is made from engine OIL PUMP, not from tranny pump. Just go under the engine and listen under oil pan...you will hear oil pump buzzing. It is buzzing because it have 6 internal gears (because of 2 place oil pickup), on the other hand W220 S55k engine oil pump and SL55 oil pump have only 2 gears (because they only have 1 place oil pick up), so that is the reasson they dont whine).I know that because i personaly swap my blown E55 engine with new S55 engine, so i had to swap oil pumps also (and i put to pieces both of the pumps to clean them) .
Also i have discovered that with thinner oil (like german castrol 0W-30) buzzing (whine) goes away at cold start, but it continues to whine at hot. On the other hand i have discovered that with thick oil (mobil1 5W-50) buzzing is heavy when cold, but it totaly dissapeared when hot. In a few dazs i will try OEM mobil1 0W-40 oil (i am not big fan of that oil, so that is the reason why i havent put it in before) or some other 40 weigjt oil and see what will happen....
Also that buzzing (whine) is present only when idle and when rolling ONLY between idle and 1700 rpm. Anythink over that rpm it is quiet.
Go and listen and report back to me what you have discovered... Also on that board there are at least 2 threads when people actualy swap oil pumps because of that whine, but with no succes-new instaled pumps did also whine.
There is aslo a lot of threads here when people are describing noticably bigger whine after new oil change. Noise eventually goes down (but never totaly quiet)-it seems that we have to have perfect viscosity oil in specific climate for oil pump to not make buzz...
Thesere are my thoughts....
