Help diagnosing what's normal noise vs possible fan clutch/pulley failure? C36
Thread Starter
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Joined: Sep 2013
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From: Tacoma, WA
1995 Mercedes C36 AMG
Help diagnosing what's normal noise vs possible fan clutch/pulley failure? C36
In another thread, "running rough and hot", I discuss a Head Gasket/Timing seal job I'm going to need to do on my '95 C36 AMG. While I'm at it and pulling accessories, I also want to insure I replace/rebuild failing accessories. For a while now, like many of you, I've been frustrated by the amount of noise I hear from the fan, fan clutch, pulley or belt tensioner area on crank. For about 2-3 minutes, the car has a loud whine. Some threads say this is normal, but could someone walk me through what the normal sequencing of the cooling system is?
When/why does this noise only occur for 2-3 mins then cycle off?
When do the 2 auxiliary fans in front come on? I didn't get them to cycle yesterday and my car is running close to 100 degrees due to head gasket/coolant leak problem.
I'll take a stephoscope to the front accessories/pulleys today - but need to know what right/wrong looks like to accurately diagnose.
When/why does this noise only occur for 2-3 mins then cycle off?
When do the 2 auxiliary fans in front come on? I didn't get them to cycle yesterday and my car is running close to 100 degrees due to head gasket/coolant leak problem.
I'll take a stephoscope to the front accessories/pulleys today - but need to know what right/wrong looks like to accurately diagnose.
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Joined: Mar 2005
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From: America
1999 C43 AMG, 2005 E55 Wagon
aux fans don't rely on engine temp unless AC system is charged.
it's the dumbest thing on earth, and I've owned 4 MB's that did it. 1994 E320, 1994 C280, and 2 C43's.
If AC system is not charged properly, the fans will never engage, no matter how hot the engine gets. If your AC system is charged just fine, then you have a failed relay/fuse. Highly unlikely both fans failed.
As for the fan clutch, it depends on which clutch you have. There are 2 that engage at different temperatures. It should kick in full speed at 100C in most cases. Manual fan sucks HP and gas and is kind of a last resort. My fan clutch doesn't fully engage below 100c. If your's is apparently whining as soon as you crank the car I'd be suspect. I'd need to hear this whine to know if its normal or something else. Can you record this? Cold start car then do a few revs, let it idle a bit.
Old school test for a failed fan clutch is a rolled up newspaper. With engine running and iddling, try to stick a rolled up newspaper into the path of the fan and stop it. If you can stop it, it's dead. If you can't stop it then it's still good.
it's the dumbest thing on earth, and I've owned 4 MB's that did it. 1994 E320, 1994 C280, and 2 C43's.
If AC system is not charged properly, the fans will never engage, no matter how hot the engine gets. If your AC system is charged just fine, then you have a failed relay/fuse. Highly unlikely both fans failed.
As for the fan clutch, it depends on which clutch you have. There are 2 that engage at different temperatures. It should kick in full speed at 100C in most cases. Manual fan sucks HP and gas and is kind of a last resort. My fan clutch doesn't fully engage below 100c. If your's is apparently whining as soon as you crank the car I'd be suspect. I'd need to hear this whine to know if its normal or something else. Can you record this? Cold start car then do a few revs, let it idle a bit.
Old school test for a failed fan clutch is a rolled up newspaper. With engine running and iddling, try to stick a rolled up newspaper into the path of the fan and stop it. If you can stop it, it's dead. If you can't stop it then it's still good.
Thread Starter
Member
Joined: Sep 2013
Posts: 88
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From: Tacoma, WA
1995 Mercedes C36 AMG
Videos of Noise and Fan Clutch test
Here is a video capturing the noise from my fan area. My head gasket leak is in the same front left corner. Note, the noise only occurs on cold start and goes away at 1:46 into video.
Then I conduct the Newspaper Test on the fan clutch. I assume the fact the fan stopped means the clutch is no good and I'll be replacing as I do head gasket work?
Thanks.
Starting to look for parts. I see threads which say the Head Gasket for the C36 AMG is unique and should have the metal tabs? anyone?
I found a part for metal tabs: 104-010-37-20
but online its identified as a "may not fit"
The online tools provide this gasket: W0133-1612644
Then I conduct the Newspaper Test on the fan clutch. I assume the fact the fan stopped means the clutch is no good and I'll be replacing as I do head gasket work?
Thanks.
Starting to look for parts. I see threads which say the Head Gasket for the C36 AMG is unique and should have the metal tabs? anyone?
I found a part for metal tabs: 104-010-37-20
but online its identified as a "may not fit"
The online tools provide this gasket: W0133-1612644
