Welcome to the North American Subaru Impreza Owners Club Friday April 18, 2014
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
NASIOC
Here you can view your subscribed threads, work with private messages and edit your profile and preferences Home Registration is free! Visit the NASIOC Store NASIOC Rules Search Find other members Frequently Asked Questions Calendar Archive NASIOC Upgrade Garage Logout
Go Back   NASIOC > NASIOC Technical > Normally Aspirated Powertrain

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads.
Reply
 
Thread Tools Display Modes
Old 08-19-2003, 10:22 PM   #1
mike270
Scooby Specialist
 
Member#: 12863
Join Date: Nov 2001
Chapter/Region: MWSOC
Vehicle:
2002 2.5RS

Default Click when start rolling

I have noticed that I get a click when I get my car over like 3mph. Does it when accelerating, never when braking, forward or reverse, only when first started up, and at night and my lights are against a building or something I can see the lights dim for a split second when it clicks.

Any idea what it could be?
* Registered users of the site do not see these ads.
mike270 is offline   Reply With Quote
Old 08-20-2003, 12:44 AM   #2
Subietonic
Scooby Specialist
 
Member#: 12588
Join Date: Nov 2001
Chapter/Region: SCIC
Location: Low Country, SC
Vehicle:
Four Count 'em
GF5,BDA,BD5, BP5

Default

ABS unit cycling?
Subietonic is offline   Reply With Quote
Old 08-22-2003, 01:30 AM   #3
mike270
Scooby Specialist
 
Member#: 12863
Join Date: Nov 2001
Chapter/Region: MWSOC
Vehicle:
2002 2.5RS

Default

Would it do this only when you start rolling regardless of how long the engine has been on. Hot or cold?

What does the cycling do by the way?
mike270 is offline   Reply With Quote
Old 08-22-2003, 01:00 PM   #4
Subietonic
Scooby Specialist
 
Member#: 12588
Join Date: Nov 2001
Chapter/Region: SCIC
Location: Low Country, SC
Vehicle:
Four Count 'em
GF5,BDA,BD5, BP5

Default

When you first start your car, the logic circuitry checks a number of different sensors, one being the ABS pressure available. These systems operate at tremendous pressure, somewhere in the neighborhood of IIRC 1.5-2.5K psi. The noise you hear is the ABS pump itself, "pressurizing" the system. It usually comes on within a few seconds after you start the car, cold, warm or hot to make sure it's up to speed, pressure-wise, and ready to go when you are. Since it's a high amp motor, it puts a pretty good draw on the electrical system so that's probably why you're seeing the lights dim.

If you want to check it out, lift your hood and look in the front right corner, left of the radiator (as you face the engine), down and to the left, attached just above the frame, is a round motor attached to a square aluminum box with small brake piping coming out of it. Have someone start you car and listen in that area. You'll hear the pump motor cycle/pressurize the system.

HTH

Br, Dale
Subietonic is offline   Reply With Quote
Old 08-22-2003, 01:40 PM   #5
mike270
Scooby Specialist
 
Member#: 12863
Join Date: Nov 2001
Chapter/Region: MWSOC
Vehicle:
2002 2.5RS

Post

But I only hear it when I start rolling. It doesn't matter how long I have been running the engine for. The ABS light comes on when I first start the car then goes away without hearing any noise.
mike270 is offline   Reply With Quote
Old 08-22-2003, 03:18 PM   #6
Subietonic
Scooby Specialist
 
Member#: 12588
Join Date: Nov 2001
Chapter/Region: SCIC
Location: Low Country, SC
Vehicle:
Four Count 'em
GF5,BDA,BD5, BP5

Default

The ABS light is just to show that it has completed a search of all the known connections, controllers, etc., and that everything is still connected, ready to go.

Re-reading your first post, I was presuming that the "click" came immediately after you started the car. At some point in the Subaru ABS development (cannot recall what year/models), the engineers added additional logic to the ABS that kept the ABS servor motor (pump motor) from initially pressurization until the car was put in motion. Perhaps to keep some unsuspecting shade tree mechanic from blasting out an eye or losing a hunk of hide when they cracked open one of the lines. So now you have to "move" the car, with the motor and the auto or manual transmission providing the motive power before the servo motor pressurizes the system.

I've gotten so used to this click with all of mine that I just don't listen for it. I did listen on my 99 Legacy this AM as I was going through my startup routine and the ABS servo motor didn't come on until I had backed the car out of the garage and started forward at 1-3 mph. This from a cold start. I checked it again after it had been parked for a few minutes later on this morning and it did exactly the same thing so I'm still pretty sure that the "click" that you identified is the ABS servor motor.

And given that your car's ABS pressurizes with forward movement, please ignore the "check it this way" advice provided earlier. Wouldn't want you to get in the way of the driver trying this would the hood open....

HTH - did it clarify it for you?

Br, Dale
Subietonic is offline   Reply With Quote
Old 08-22-2003, 04:03 PM   #7
MY99 2.5GT
Scooby Specialist
 
Member#: 5030
Join Date: Mar 2001
Chapter/Region: MAIC
Location: Martinsburg, WV, USA
Vehicle:
1999 Legacy 2.5GT
05 Legacy GT 06 Armada

Default

Did you recently replace your brake pads?

I replaced my pads with Axxis Metal Masters and have just recently been experiencing a click when I apply the brakes when the rotors and brake assembly are still cold. My subaru tech friend tells me its just the pads shifting slightly because of a little bit of play when there cold. He says its common for replacement brakes.
MY99 2.5GT is offline   Reply With Quote
Old 08-22-2003, 05:50 PM   #8
mike270
Scooby Specialist
 
Member#: 12863
Join Date: Nov 2001
Chapter/Region: MWSOC
Vehicle:
2002 2.5RS

Default

That makes sense now, and what you describe seems to be exactly what I am seeing. Thanks a lot for all your help. I was never concerned about it but just curious as to what system would be causing this.

Also I didn't recently change my brake pads but the first time I brake when the brakes are cold, I also here a click from them. I still have a completely stock brake system as well.
mike270 is offline   Reply With Quote
Old 08-23-2003, 02:44 AM   #9
Subietonic
Scooby Specialist
 
Member#: 12588
Join Date: Nov 2001
Chapter/Region: SCIC
Location: Low Country, SC
Vehicle:
Four Count 'em
GF5,BDA,BD5, BP5

Default

You should be able to completely replicate the brake pad shift "click" every time you back up from a parking spot. Simply come to a stop with your foot on the brake. Keep your foot on the brake, set your e-brake and turn it off. Just keep your foot on the brake pedal through that whole evolution. When you get back in your car to move it, put your foot on the brake pedal, start the car, put it in reverse, release your e-brake, and back up coming to a stop in reverse using the brake pedal. When you start to move forward, the first time that you hit the brake pedal you should get a snap/click sound from the front brake pads shifting. This happens even with stock brakes with little to no wear on them. Just the nature of the beast... so to speak.

mike270

Sounds like you're satisfied that your question is answered. The lights dimming is almost a dead give away, unless you're also running your A/C and that "clicks" on and off too causing the lights to dim... but from your description it really sounds like your ABS servo motor.

Br, Dale
Subietonic is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Cold Start click when accelerating Subee05 Factory 2.5L Turbo Powertrain 4 04-14-2010 03:21 PM
help car just clicks when trying to start GuitarkidM3 Electrical & Lighting 3 10-18-2008 10:22 AM
07 LGT auto clicks when starting out kcmusa Transmission (AT/MT) & Driveline 1 05-31-2007 11:13 PM
Rapid clicking when trying to start memccain Texas Impreza Club Forum -- TXIC 8 01-17-2007 11:03 PM
Rapid Clicking When Attempting to Start Star*Child Electrical & Lighting 15 05-11-2005 01:21 PM


All times are GMT -4. The time now is 08:01 PM.


Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2014 Axivo Inc.
Copyright ©1999 - 2014, North American Subaru Impreza Owners Club, Inc.