Hi all,
Looking for some advice, please.
I have a 2001 cruiser that I've owned since 2009. Somewhere around 125k miles. Just recently it started making a noise from the engine bay at the front of the engine - serpentine belt territory.
The sound is rotational; noise volume corresponds with engine speed - it gets louder at higher rpms; it happens parked in the garage as well as on the road; being in gear has no impact on the sound. It ONLY happens with the AC button turned on (or the defrost, which actually turns the AC on).
Some possibly (but probably not related) history: the rig originally had a rear AC but a few years ago the lines to the rear under the car corroded through, so I capped the lines, pulled a vacuum and recharged it to spec (I got cheap gauges and a vacuum pump from harbor freight). It has run fine for maybe three years like that.
To reduce the places where a noise could be coming from, I first replaced the idler, tensioner and serpentine belt, to eliminate any potential noise there. Quieter in general, but still lots of noise if the AC is turned on. Next I replaced the large bearing in the AC pulley (pressed in a new one). Even quieter in general, but still lots of noise when AC is turned on. One last easy item to try, I put on a Continental Gatorback belt, and still quieter in normal operation, but when AC is on I get the noise. At least I know all of my bearings in the serpentine area are in good shape.
Coolant pressures are good.
The front most part of the AC clutch does engage (locks firmly to the the pulley part) when the AC is on.
The air seems to blow cold, but it's pretty hard to say whether that is the AC or just the outside air, since ambient temperatures are in the 30's Fahrenheit where I live.
The air gap between the clutch parts is too low (.007 in when the spec at 4 Seasons is .016-.030). I did reinstall the original shim when I reassembled the clutch, but apparently clearances are different and I need more shim. However, the parts of the clutch spin independently when the AC is off, so I'm not overly worried that that is the cause... But maybe it is! Could this cause noise?
I have a phone video, but am not sure how to post it. Trying photobucket: Video by cdsprigg
It seems like it might be rotational metal on metal. As I typed this, I wonder whether having not enough shim thickness might cause the nose piece of the clutch to somehow rub against the rotating part of the pulley creating this noise? BUT, if they are locked together with the electromagnet, they shouldn't be moving relative to one another.
I can't swear that this noise is the same exact noise I started chasing at first (but I think it is the same and my wife does too). If that is true, it points away from anything I've done in my repairs. But I can't discount the possibility that I messed something up.
What if I somehow put the wavy circlip on backwards after I replaced the bearing? Could that cause noise? Grasping at straws here...
So frustrated...
Thanks in advance for any guidance.
Charlie
Looking for some advice, please.
I have a 2001 cruiser that I've owned since 2009. Somewhere around 125k miles. Just recently it started making a noise from the engine bay at the front of the engine - serpentine belt territory.
The sound is rotational; noise volume corresponds with engine speed - it gets louder at higher rpms; it happens parked in the garage as well as on the road; being in gear has no impact on the sound. It ONLY happens with the AC button turned on (or the defrost, which actually turns the AC on).
Some possibly (but probably not related) history: the rig originally had a rear AC but a few years ago the lines to the rear under the car corroded through, so I capped the lines, pulled a vacuum and recharged it to spec (I got cheap gauges and a vacuum pump from harbor freight). It has run fine for maybe three years like that.
To reduce the places where a noise could be coming from, I first replaced the idler, tensioner and serpentine belt, to eliminate any potential noise there. Quieter in general, but still lots of noise if the AC is turned on. Next I replaced the large bearing in the AC pulley (pressed in a new one). Even quieter in general, but still lots of noise when AC is turned on. One last easy item to try, I put on a Continental Gatorback belt, and still quieter in normal operation, but when AC is on I get the noise. At least I know all of my bearings in the serpentine area are in good shape.
Coolant pressures are good.
The front most part of the AC clutch does engage (locks firmly to the the pulley part) when the AC is on.
The air seems to blow cold, but it's pretty hard to say whether that is the AC or just the outside air, since ambient temperatures are in the 30's Fahrenheit where I live.
The air gap between the clutch parts is too low (.007 in when the spec at 4 Seasons is .016-.030). I did reinstall the original shim when I reassembled the clutch, but apparently clearances are different and I need more shim. However, the parts of the clutch spin independently when the AC is off, so I'm not overly worried that that is the cause... But maybe it is! Could this cause noise?
I have a phone video, but am not sure how to post it. Trying photobucket: Video by cdsprigg
It seems like it might be rotational metal on metal. As I typed this, I wonder whether having not enough shim thickness might cause the nose piece of the clutch to somehow rub against the rotating part of the pulley creating this noise? BUT, if they are locked together with the electromagnet, they shouldn't be moving relative to one another.
I can't swear that this noise is the same exact noise I started chasing at first (but I think it is the same and my wife does too). If that is true, it points away from anything I've done in my repairs. But I can't discount the possibility that I messed something up.
What if I somehow put the wavy circlip on backwards after I replaced the bearing? Could that cause noise? Grasping at straws here...
So frustrated...
Thanks in advance for any guidance.
Charlie