BMW E30 - need help - tapping noise from dash!

[AztecTT]

Hey guys, looking for some help with my gf's dad's 1991 325.

The other day, his car developed a tapping noise (not lifters or rod knock), coming from the driver's side of the dash.

I hopped in the car last night to hear it. It seems speed-dependent. From a stop, the tapping begins around 5mph, and increases with speed up to ~34mph. It doesn't seem to be rev-dependent, though.

He thought it was something to do with the heater core, as he just got some bypass hoses replaced, and had previous heat problems. It happens regardless of heat being on or off.


IMO, it sounds like a solenoid (like that clicking noise you might hear from your boost controller's solenoid), but it's louder and slower (at start, picks up speed when accelerating).


Any ideas?

[Jeff told me to]

More then likely a bad ground somewhere. What ever is making the noise may be getting an intermittent ground and then losing it, like turning a light switch on and off. When you have a moment ram you hand up under the dash and see if you can feel the clicking. Once you find the source of the sound check its grounds.

It could also be old/dirty relays[that is if the sound is around the fuse box] Maybe a fuel pump relay if changes with speed.

Those are my guesses
Ashley

[CiZiN]

my brother's pathfinder does the same thing. When it gets really warm it went away or got quieter. It turned out that he had a crack in the header and the air was escaping, hitting the firewall. Not saying it what your problem is but a good place to look.