Power Steering Rack Emulating Ping/Chatter Sound?
 

Here's the story...

A few months ago I bought a 1997 Rav4 to be a backup vehicle to my 4Runner project. I went into knowing it had a few issues... valve cover leak, oil plan leak, power steering rack was leaking like a sieve and it had a very intermittent ping/chatter sound that I suspected at the time was pinging do to carbon build up.

I first tried to tackle that ping/rattle noise pretty aggressively. I ran 93 octane, several tanks of fuel injector cleaner (Lucas, Royal Purple, Sea Foam) as well as Berryman's through the brake booster line and water vapor through the throttle body. None of them seemed to remedy the situation.

I also turned it over to a local shop and let them drive it home for the night to see if they could hear it. They said they thought they heard it for a split second one time but it didn't last long enough for them to get a good listen. They suspected based on their assessment of the motor and very healthy compression numbers that it was more likely the clutch and not the motor.

It continued to occur randomly off and on up until I replaced the rack and pinion two weeks ago. Ever since then I have not heard a single ping or chatter which I expected to by now.

I've been working on vehicles for nearly 20 years and I've heard pinging and bad clutches before... but I've never heard of a rack making a similar noise. I know to expect groan from a pump, but I've not heard of this.

I'd like to believe that my ping/chatter issue was fixed by the rack but it doesn't add up in my head. Don't get me wrong, I'm not complaining - it's driving great.

Just wondering if anyone has ever heard a ping/chatter sound come from a rack? Could it be that it was this all along? Note: the rack and none of the components were lose/no mounts were worn. Everything was on there tight.