Sweet430

When I brake (complete stop or just slowing) I get a short (2-3 second) motorized purring sound -- like something's getting checked or adjusted... It happens more often than not, yet I'm unable to determine a pattern. It sounds like it's coming from under the dash, under the hood, somewhere up front, I just can't tell where.

It started a day or so after I had the alignment checked (which was only the slightest bit off, so only a small adjustment there...)

Over the phone, Lexus service didn't have any ideas (of course without bringing it in...) How about anyone out there?

Thanks a bunch
~Janine

Harold57

That sounds like your antilock brake system kicking in.

Sweet430

Thanks, Harold ... I wondered about that, but also wondered why suddenly it became so audible. I never used to hear it... something during the alignment maybe?

Harold57

The antilock brakes shouldn't be kicking in unless it thinks that the tires are slipping or locking up when they shouldn't. I can't remember if an idiot light comes on in the dash when it does, you might check your manual on that. If it does, it will be real easy to identify it as such.

Typically the antilock taking action won't sound like an electric motor purring but more like a clicking sound though.

(Antilock can kick in when going over a bumpy surface while the brakes are applied. What happens is the tire leaves the ground and loses the rolling resistance from the pavement and the brakes lock up the wheel. That will make the antilock system think that the tire is sliding on the pavement.)

If the conditions aren't right to make the antilock kick in, maybe the mechanics tweaked or bumped something they shouldn't.

Sweet430

Thanks again, Harold. Good info. Although it's definitely a purr not a click, it just seems too coincidental re: the alignment. And, I'm not driving in any abnormal conditions whatsoever.

So back to the shop I go, I guess.

~ Janine

deadeyed

Could it be the brake assist pump about to give?? Happened to me when I have the GS. Just a guess...

Bubba

I have had the same problem ever since I've had my car (four years). I would also call it a very faint humming-type noise from coming from under the dash near the speedometer, and it's not the ABS kicking in. I have noticed there is no hum if you apply the brakes again in less than 30 seconds which is odd. It's almost like something resets in 30 seconds and the hum comes back again.

Turboo

I have the same sound and Lexus dealer says it is the suspention auto adjustment!!!
they claim that it will only comes if you drive the car in sport mod by either speeding over 60 mile/hour or sudden kick off the acceleration padel or high RPM or switching the ECT power or the VSC/OFF!!!
I checked and it is true that I only hear this noise when I do any of the mentioned things that the dealers said.

Sweet430

Just got back from (a well needed vacation and see a few more posts here. Thanks!!

Bubba, you describe it to a Tee. Exactly. Have you ever had it checked out? Mine didn't do it... then it did... which makes me think the obvious -- that something's wrong. I have an appt. on Friday and will let you know the diagnosis.

Turboo, great info, I'll give those a combinations a try and see if that's it. If so, I may cancel that appointment Friday

Deadeyed, when making the appt. I chatted with the shop about the brake assist pump so am going to have that looked at as well, thanks

I'll let y'all know.

~Janine

Sweet430

Well, here's the diagnosis of the day...

The ABS system pump is running more frequently than it should. The fluid level's good and in good condition. No external leaks were found which indicates perhaps internal leaking causing a loss of pressure.

They scanned the computer data for malfunction codes and found none present or in the data history.

So... their advice:
Since it's a high $ repair, wait till the ABS light comes on and get it repaired then
-- or --
Take it up with Lexus since the ABS system pump shouldn't be a problem at 50,100 miles (yeah... just outta warranty by 100 miles and seven months).

Any 'n' all advice welcome, and thanks again

~Janine

Harold57

Interesting, so it was the ABS acting up afterall.

Some dealers can be reasonable when you point out that the warranty is just barely expired. Also point out that the ABS really shouldn't be giving you grief at this point in its life, ESPECIALLY SINCE IT IS A LEXUS, WHICH IS ONE REASON YOU BOUGHT A LEXUS. (Emphasis on the capitalized part and the fact that you don't expect a Lexus to have problems this soon kind of gives them pride in their product and a feeling of responsibilty to take care of it and you.)

They may go ahead and warranty it or they may just charge for parts or something. It is worth a try. I have seen them make exceptions. However, I'd do it as soon as possible since you are only 100 miles over and already 7 months past (the 7 months will hurt you more than the 100 miles though). Point out that it is barely 100 miles over, not the 7 months past.

Sweet430

You were absolutely right, Harold. Great diagnosing

I'm going to give Lexus customer service a shot, and do as you say, pointing out the 100 miles and not the seven months. Even though the car's an '05 it hit the road in October, '04. The unfortunate thing is the car's a lease return I purchased from a broker, so no dealership involved.

Soon after buying it, it appeared the lessee had broken then glued the third brake light housing. I took it up with Lexus as at the time I was under 50K but still over the months. And, as they felt I've been a loyal customer (2 Lexus' and two Toyotas), they "kindly" paid for half the part and none of the labor. That was a $200 part so probably be wishful thinking they'll step up to the plate here...But, one never knows

Thanks again for your help in this.

~Janine

Turboo

Good that you solved your problem
Happy 4 you
Now it is my turn to go and shout at my Lexus dealer here as they were BS me about the suspension auto adjustment!!!!
Unfortunately I don’t have any warranty on my car but that does not give them the right to give wrong diagnostic about this problem?!
I noticed that Lexus dealer all over the world are most of the time not sure of what is the real reason for any problem in the car and most of the time it is either luck or coincidence that solves our cars problems?! Don’t you agree with me?!

mrblister

I have found when I have some issue and take my car in to the dealership. I allways give them my opinion of what the problem may be. I do a lot of reading about my car prior to taking it in and I feel many times I am more informed then they are. Since the clock is running as soon as the mechanic starts to look at the car I watch from the customer observation area . I believe that me telling them my opinion does save time and thus saves me money. Of cours the dealerships sometimes use there repair book guide time when figuring your bill. I remind them that I watched and saw it only took one hour VS the hour and half alloted .

Pearlpower

iTrader: (2)

The noise is just the antilock system filling up which is normal to a degree. If it is occurring at every stop something is probably wrong.