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Turbo R HVAC Knocking Sound?

2K views 5 replies 4 participants last post by  r5gordini 
#1 ·
Hey all -

My recently acquired 1989 Turbo R has some issues with its central air.

It sporadically works as intended, although the temperature control seems not to function, but sometimes makes a dull knocking sound from within the dash that seems to change its quickness/frequency/pace when the motor is revved. While the system is off, there is no such knocking sound, so usually I just run with it disengaged. Any ideas?

Secondly, I think the AC needs refreshing - where is the Refrigerant port underneath the hood on these cars? I do not have access to the original owners' or repair manuals.

Thanks!
 
#6 ·
I have a similar knocking noise that varies with fan speed but I would call it more of a light clicking/whirring sound.

I believe one of my fan motors is faulty - you can check which one by disconnecting the wiring from each of them in turn. If you disconnect both motors and the noise is still there, you know it's something else.

It could also be as simple as a small leaf or similar stuck inside one of the vents.

Andrew
 
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