A mysterious buzz...
Hey guys,
First of all, sorry about the length but I want to try to answer as many questions as possible before they need to be asked.
So I hate doing stuff like this because I realize how tough it is to know anything at all without being next to a car, but I'm giving it a shot anyway. I started my '87 325i today with the hood open, and I heard an unusual buzz coming from the front of the motor area. I found that it appears just under 2k rpm and is significantly louder than the usual valvetrain noise. It is not the fan because I stopped it with my finger and started the car; the noise remained. I also took a ratchet extension to listen for vibration, but nothing seemed louder than anything else. It REALLY sounds like it's coming from the thermostat housing area, but I don't know what could be there to cause it. Maybe a loose thermostat vibrating? Are there any other parts around there?
To clarify, I checked the alternator, cap, valve cover, block, A/C clutch (even though it still isn't attached), and fan surround.
I'm going to look into it in more detail next week, but I'm headed to Watkins Glen early tomorrow and always appreciate second opinions.
Thanks for any input!
First of all, sorry about the length but I want to try to answer as many questions as possible before they need to be asked.
So I hate doing stuff like this because I realize how tough it is to know anything at all without being next to a car, but I'm giving it a shot anyway. I started my '87 325i today with the hood open, and I heard an unusual buzz coming from the front of the motor area. I found that it appears just under 2k rpm and is significantly louder than the usual valvetrain noise. It is not the fan because I stopped it with my finger and started the car; the noise remained. I also took a ratchet extension to listen for vibration, but nothing seemed louder than anything else. It REALLY sounds like it's coming from the thermostat housing area, but I don't know what could be there to cause it. Maybe a loose thermostat vibrating? Are there any other parts around there?
To clarify, I checked the alternator, cap, valve cover, block, A/C clutch (even though it still isn't attached), and fan surround.
I'm going to look into it in more detail next week, but I'm headed to Watkins Glen early tomorrow and always appreciate second opinions.
Thanks for any input!
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