Abs Hummings

[Fuzpile]

I've had my 97 Legacy about a year now and except for some initial work it is fine, Except this certain Humming like a motor running.( another one) The origin of this noise was from either the ABS distributor or maf sensor. Unplugging the MAF kills the engine and noise stops plus there is no moving part. My manual desn't go into the ABS distr AT ALL. This one appears to have like a motor or distributor deal atop. There are no warnings lit up and light works. It is like it is continually reacting to a situation which isn't there.

 

Sometimes at a stop with pedal depressed there is a pulsing so methinks it related. I've searched the archives here and find nothing.

Any ideas folks? TIA .

[Legacy777]

It definitely sounds like it's an ABS issue. It may be running due to a bad input from a wheel sensor, or something may be wrong with the wheel sensor. You can try unplugging the ABS unit to verify it stops humming. You could also maybe try resetting the ABS computer. Pulling the battery cable for an hour or so should do that.

 

If none of that helps, you could try disconnecting each wheel speed sensor connector at one time to see if it's possibly getting a bad signal from one of the wheel sensors.

 

Short of that, you may need to have a shop or the dealer hook up to the ABS computer to see if anything looks out of the ordinary.

[porcupine73]

I wasn't sure, is it running all the time? Some of them had faulty relays that then made the hydraulic unit run all the time.

[idosubaru]

there's a common relay failure as porcupine mentioned that causes this, sounds like you might want to read up on those.

[1-3-2-4]

there's a common relay failure as porcupine mentioned that causes this, sounds like you might want to read up on those.

 

My 95 L had a faulty relay (it's still in the car) it drained my battery dead and the giveaway was when I replaced the battery it started up again..

 

funny thing it has not gotten stuck again in a little over a year now (knock on wood)

 

It's just something I haven't thought about getting done because it's been tame for now.. ABS saw a lot of action last winter.

[Fuzpile]

Wow. Thanks folks!. I should've asked earlier. Yes it hums as long as the engine is running. I'll let y'all know what i find. Thx again.

[subaru360]

The abs on these cars is horrible, it's nothing but trouble. I can't imagine spending any money to repair the abs on a 15 year old car. At the first sign of abs trouble I just unplug everything, take the bulb out and am done with it.

[1-3-2-4]

What is wrong with it?

 

the only time I had problems with my car is when my car got flooded last year with a huge rain storm.. the ECU got flooded as well as the ABS unit.

 

both spent 48 hours drying and I've never seen another problem.

[johnceggleston]

there have been some reports of the humming continuing after the car is turned off. maybe that's next.

 

i think there is an improved replacement part for the 95s

[1-3-2-4]

I guess you are talking to me? I know they have a replacement and they go to show how you can tell if you already has the replacement.

[Fuzpile]

The pedal pulse happens rarely but will be investigated. I pulled the ABS solenoid fuse(under dash) then later both the relays in front of the ABS distr. The Hum is still there. I may haved caused wasted braincells. This is a Very quiet engine. Once the lifters settle down you basically just hear the belts spinning and the Humm. So maybe a fuel line is against a brake line somewhere then gets magnified right there. I'll let y'all know. Thx.

[johnceggleston]

check to see if the air filter box is installed correctly.

 

is this a new sound or a recently purchased car, ??

[Fuzpile]

J .. it's not recently purchased and while I've had the filter out,replaced or anything touching, it has been checked again recently. Stuff all where it should be according to manual pics. If you are going where I think, then there is that nose hangout which i suppose is a harmonic dampener. It should all be good but you know more than i do. it's not touching anything.