Machine Gun Sound
01-23-2018, 06:55 PM
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Machine Gun Sound
No sooner had I ironed out my no oil pressure problem when a new one showed up.
On turning the key to the on position, a machine gun sound comes from the central dash/clutch area. (It also sounds like a fan with baseball cards hitting the blades.) If the motor were running I'd say it could be the throwout bearing, but on searching the forums this problem seems to be an AC solenoid. This is on a 1986 944 NA 5 speed with factory AC.
It's been too cold in the garage to run down this problem for now, but what I find inexplicable is this: If I just lightly depress the clutch or the brake, the sound stops. Remember, this is without the motor running.
I'm genuinely mystified what either the clutch or the brake has to do with an AC solenoid.
On turning the key to the on position, a machine gun sound comes from the central dash/clutch area. (It also sounds like a fan with baseball cards hitting the blades.) If the motor were running I'd say it could be the throwout bearing, but on searching the forums this problem seems to be an AC solenoid. This is on a 1986 944 NA 5 speed with factory AC.
It's been too cold in the garage to run down this problem for now, but what I find inexplicable is this: If I just lightly depress the clutch or the brake, the sound stops. Remember, this is without the motor running.
I'm genuinely mystified what either the clutch or the brake has to do with an AC solenoid.
Last edited by Coloradoguy; 01-23-2018 at 07:20 PM.
01-24-2018, 08:54 AM
#2
On 944 cars, the AC/heater fan is always running when the ignition is on. It's not a bug, it's a feature.
My guess, the fan blades are hitting an obstruction. Turn up the fan speed, and it will wear away the obstruction. In the meantime, turn up the radio.
My guess, the fan blades are hitting an obstruction. Turn up the fan speed, and it will wear away the obstruction. In the meantime, turn up the radio.
01-24-2018, 11:48 AM
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Thanks, guru, but I forgot to mention that I pulled the AC blower relay thinking that it may be the fan, but the sound persisted. In any case I would be reluctant to try and wear away the obstruction; what if it was a wire loom, for instance?
I still don't see how touching either the brake or the clutch could affect the sound.
Supposed to creep into the 50s today so maybe I can nail down exactly where the sound is coming from.
I'll post results.
I still don't see how touching either the brake or the clutch could affect the sound.
Supposed to creep into the 50s today so maybe I can nail down exactly where the sound is coming from.
I'll post results.
Last edited by Coloradoguy; 01-25-2018 at 10:48 AM.
01-26-2018, 02:29 PM
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Turns out the noise is actually coming from the cruise control unit mounted next to the battery. I'd noticed that the PO had disconnected it for some reason and I'd hooked it back up right after purchasing the car. It's been fine for a few months but suddenly started making a loud machine gun sound when turning the ignition on. This also explains why tapping the brake or the clutch makes the sound stop.
I'm not really a cruise control kind of guy so I simply disconnected the harness to the cruise control for now and will no doubt tackle the problem at some future date.
I'm not really a cruise control kind of guy so I simply disconnected the harness to the cruise control for now and will no doubt tackle the problem at some future date.
