ACD Buzzing
 

Update:
It was one of the front, lower ball joint shields. Somehow it got bent out of shape and was rubbing on the brake rotor. I guess that made it vibrate "just right" so that it made the noise.

Now, surely I'm not the first to post about this, but I couldn't find anything in a search. Yes, my brain is toast (it's been a long day), so I probably just missed it. Please link me to the thread if there is one!

In the mean time:, my ACD started buzzing. I bled it, was quiet, then started again. Now... I think I may just need a rebuild because when I bled the ACD unit, I'd have have someone hold down the gas pedal, then I'd open up the bleeder while the pump was pressurizing. I had to be quick because it would only run for about 2-3 sec. Did I do it right? It's been forever and I honestly can't remember.
Anyway... When I'd crack 'er open, I wouldn't get any air, but fluid would only trickle out. I'm 99% sure it used to come out quite a bit. Maybe that was just a LOT of air?? I assumed it would spit and bubble like the brakes.
So.. also assuming I am bleeding it right, I guess the pump is tired and needs a rebuild? It would figure, seeing how I just dropped about $5k in driveline parts to FINALLY be able to drive the damned thing.
Lastly: didn't EvoScan use to have an actuator "button" for the ACD?? If so, it's not there now. Using the gas pedal sucks. It takes forever for the pump to actuate. It's so unpredictable.

The FSM says to bleed the ACD, instead of using the gas pedal to cycle the ACD pump, we just turn the wheel left, right, then center, open bleeder, close. Have I completely forgotten how to do this? :lol: I literally haven't messed with my ACD pump since 2010.

I think this is my ACD unit getting me back for talking crap on it in other threads. "Oh, you gon' appreciate me!". :lol:

Video:

You know me Jason, this is beyond my experience. But, no code 82 or the dreaded 3 lites?

Heres a 16 page ACD thread where a lot of symptoms were discussed

https://www.evolutionm.net/forums/ev...l-pay-you.html

Gracias! No codes or lights, but the ACD is tuned and I'm not sure how that affects fault warnings.

I had someone turn the wheel left/right twice before hitting the gas pedal and got much more fluid coming out. We also found if we turn the car off, then back on again, we don't have to wait so long for the pump to run after hitting the gas pedal.
I'll drive it today and see if that was the problem. I'm hopeful, seeing how more fluid was coming out each time and it was more consistent.

Unplugged the.unit. Still buzzing, so.it's as long as it has power. I bleed it, then starts buzzing within a mile of driving. I'll update as I investigate.

Also, when I swapped the trans, I did not loosen the banjo on the tcase. I just moved the t case out of the way like I always have

Update:

I vacuum bled the unit. 100% fluid coming out. Same result: drive about half a mile and started buzzing again. I can find no breaks in the system where air could be getting in. I'm going to order a rebuild kit and see how that goes.

Jason. Wonder why the ACD is failing? We have West coast cars so we dont deal a lot w/any corrosion issues. Dont suppose youve done a lot of wet driving?

Curious what the tear down pics will look like? (take pics)

I'm stumped. the only thing I did different this time than any other was to use a tie down strap to raise the tcase out of the way enough to not fight with it during my swap. Maybe I raised it enough for fluid to run back?. Even still, it couldn't move too much because the nose was still in the tunnel. I though maybe I damaged the feed line during.. but there is no fluid on it anywhere.
@kikiturbo has offered to ship me his box to test out the pump and see what's up. It provides a way to bleed the pressure side of the pump, which I guess doing the steering wheel/gas pedal thing doesn't quite work.
If that fails, THEN a rebuild.
I'm also trying to figure out if there is a way to cut power to it so I can at least drive the car to Cars N Coffee without embarassing myself LOL

just unplug the big connector with 2 fat wires that provides power to the pump.. you can unplug the small one too, but you will get 3 lights on.. In fact, if you just unplug the pressure sensor on the pump, it will not work at all.. good test really.

I unplugged the two on the front of the pump. Still made the buzzing noise. :crap:

then it is not the pump...

there is a large electrical connector that powers the pump motor.. unplug that..

If while you're bleeding it, the pump is not making this noise and you have the noise with the pump unplugged, its definitely not the pump. I assume you just had the trans out right?

Almost sounds more like something just right next to the flywheel hitting the teeth. Does it change with revs?

Also sorta sounds like powersteering pump. Have you checked that fluid with the car running?

There are 3 connections on the pump assembly, one for the motor(the only thing that could be buzzing) one for the pressure sensor and one for the solenoid. Unplug the one that goes to the motor for the pump, should be obvious and see if noise goes away.

The small plugs on the pump are the solenoid and the pressure sensor. If those are unplugged you'll get a fault and the pump won't run.