M113K Oil Pump Noise
#1
M113K AC Compressor Whine?
*** Issue has been found, It’s the AC compressor pulley/clutch
Just got the wagon buttoned up after replacing all the pulleys and tensioners and water pump on the front of the engine as well as the power steering pump and the car is still making the whining noise that I had originally replaced all that stuff for.
The noise the car is making is exactly like that of the oil pump on start up, but the issue is that it isn't going away once the car is warmed up. The noise gets louder as you rev the motor in gear when driving and in neutral. I really do not want to even think about replacing the oil pump, which is why I'm posting here hoping someone has had a similar issue that they fixed relatively easy. Any ideas?
Just got the wagon buttoned up after replacing all the pulleys and tensioners and water pump on the front of the engine as well as the power steering pump and the car is still making the whining noise that I had originally replaced all that stuff for.
The noise the car is making is exactly like that of the oil pump on start up, but the issue is that it isn't going away once the car is warmed up. The noise gets louder as you rev the motor in gear when driving and in neutral. I really do not want to even think about replacing the oil pump, which is why I'm posting here hoping someone has had a similar issue that they fixed relatively easy. Any ideas?
Last edited by 91180; 09-01-2022 at 07:04 PM.
#2
MBWorld Fanatic!
Joined: Jun 2020
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04 E55 AMG (totaled), 07 S550 4Matic, 14 E63S
Might be worth an oil pressure check. Hot, cold, idle, high rpm. If everything looks good, maybe ignore. Only thing I'd be worried about is a damaged O-ring causing partial starvation and aeration of the oil (possibly leading to more noise).
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Sulaco (08-30-2022)
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#13
that is normal. the oil pump uses straight cut gears and they get nosey at times. My 2006 was louder than my 2005 is. There is a 46k mile difference between my current and my last one. I switched to 5w40 and the noise got a little quieter. Don't loose sleep over it.
#14
#15
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2015 Challenger Hellcat, 2023 Ram 3500, 2005 E55 Wagon, 2019 GLC63s
I have a 2005 E55 Wagon as well and I have the same noise that never goes away. The mechanic thinks its the power steering pump but nothing comes up in the star scan as a issue in the car.
R.K.
R.K.
#16
Just perform the oil pressure check. The oil pump does have to fill that front sump - but even after that seems loud. Bearing sound, power steering whine, straight cut oil pump gear all sound similar I suppose. I've attached the oil check procedure.
#19
Yes. I actually tapped into the oil filter housing and have a oil pressure switch wired to an led light hidden in the left ac vent.
These cars have no oil warning system but really when has a Mercedes oil pump ever failed ?
These cars have no oil warning system but really when has a Mercedes oil pump ever failed ?
#22
Took the belts off today. The car was much quieter after removing them. It’s in fact the AC compressor. Thanks to everyone that contributed. the video link I posted above is exactly what the car is sounding like, so if your car is making a similar noise after being warmed up, the AC compressor pulley/clutch is a likely culprit.
I just ordered Denso 471-1474 off Amazon for $290. Hopefully the wagon will be turn key ready for an epic road trip in the next few days.
I just ordered Denso 471-1474 off Amazon for $290. Hopefully the wagon will be turn key ready for an epic road trip in the next few days.
#23
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Joined: Jun 2020
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04 E55 AMG (totaled), 07 S550 4Matic, 14 E63S
I had a whine on my S550 that conventional wisdom said must be a power steering pump. On recommendation from others, I replaced all tensioners and belt. Same noise. Finally someone said these A/C pulley bearings are known issues, and sent a MB bulletin that essentially walks through some of the common issues. I ordered a short belt to isolate the A/C compressor and bam, that was it. New pulley from eBay and I was back in business.
#25
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Joined: Jun 2020
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04 E55 AMG (totaled), 07 S550 4Matic, 14 E63S
It was on my S550 but no clue about the E55. On the S550 there is no clutch; it's a variable displacement pump.
All I was saying was it turns out that is a common source of issues on M273s, and I was happy it was relatively cheap and easy to repair. Curious if someone knows more about the E55.
All I was saying was it turns out that is a common source of issues on M273s, and I was happy it was relatively cheap and easy to repair. Curious if someone knows more about the E55.