*Newby* Clicking sound underhood?

[rranger]

I'm new to the 4 Runner world. I just bought a 2001 SR5 4wd Automatic with 120,xxx miles. 1 owner, never left the town she lived in, and zero rust. I'm very Happy with the 4Runner.
T4R forum has been very helpful, I've already done the brakes, plugs and wires, fuel filter, air filter.
BUT, My question is when I start the 4R in the morning the sounds like an electric motor running near where the brake reservoir is and then a "clicking" sound like a relay that stops it. The relay "click" comes from the passenger side. It will cycle 3 or 4 times then stop, but keep cycling evey 4-5 mins. Is this normal? or is there something I should know about?

Thank Russ the Newby.

 

[BrianSD_42]

does it happen in neutral?

does it happen in drive stopped with the parking brake on?

I had a ticking sound develop about 1 year after installing a K&N. I was perplexed for awhile until I realized that the K&N Cold-Air intake's bottom bolt was loose. Whenever the truck was in drive it would make that sound.

I got new bolts and problem was solved.

 

[BigFishAllDay]

I think that it is probably one of two things that you are describing:

1. 2001's have VSC/TRAC (vehicle skid control/traction control) that is part of the ABS. At startup, and while driving around, the ABS system will make a noise like you described as it tests itself periodically.

-OR-

2. On my 2001, the Throttle Position Sensor makes a high pitched buzzing noise. You can only really hear it with the key in the ignition, igntion position set to on, and the engine off. If you put your ear by the throttle body, you can hear the TPS buzzing. I have confirmed w/other owners that this is common.

I think it's most likely #1.

 

[rranger]

Thank you BigFishAllDay, It would make sense with the #1 answer. Thanks for getting back to me so quick.

Thank you as well brianemc2 42 but I have not put in any other filter but stock.

 

[RunninInGA]

Mine does this also. It's the ABS module performing its self check function. I thought mine did it more often than it should, but the previous owner said it has done this since day 1. ABS works fine, so I'm simply monitoring it for strange behavior.

 

[SST221]

Our TR4's have a hydraulic power brake system, the relay is turning on the pump to provide the "power" in power brakes. The pump will charge system upon start-up and then every few brake actuations after that.