08 rdx.
last day or two getting a humming noise for maybe 10 seconds then it stops.
might be from dash or engine compartment.havent pinpointed it as of yet.
doesnt happen that often.no warning lights coming on .
anybody have any info?

im hesitating bringing it in.
if dealers dont actually hear the noise when they test drive they often dont take any action.would a diagnostic test reveal the problem?

il call acura tommorow.
it will probably take a week before they let me bring it in.

 

Maybe the A/C fan motor?

 

nope it isnt that.im well familiar with that sound.

 

Dealer wont fix it if you cannot duplicate the sound, although you could always take video if that happens again. :p

 

im going to acura friday.

i dont know if they will actually hear it.
at this stage its not happening often or for too long when it does.
maybe they've seen or heard of this before and they will know where to look.

anyone know if the computer will identify any problem if no message light comes on the dash?

 

It might be your fuel pump pressurizing the system.

 

ABS self check?

 

isnt the abs self check a pulsating sound?
this noise doesnt pulsate.
i drove 40 minutes to dealer,40 minutes back no noise.
mechanic test drove no noise.
i went for a ride with him no noise.
he mentioned if no warning lights come on he cant identify the problem.

he did a safety check said front brakes were down to 1 mm,and rear 3mm.
he mentioned when he test drove it and went into turns he heard warning sensors.
ive yet to hear them.perhaps the noise is brake related.
anyone know if the brake booster releases any pressure or air?

acura wanted 340. front brakes,i dont know if that includes any resurface of rotor if needed,or thats another charge.my guess another charge.plus 340.for rear brakes.
plus another 175. for a brake system flush.
that totals out to 855. plus tax and a possible rotor charge.
i passed.

i get my parts online from bernardi acura boston mass.
their price is front pads 55. rear 46.
the local dealer this morning wanted 93. front,80.rear,for the pads

is brake system flush needed or just another way for dealer to pad the job?
car has 32,000 original brakes and brake fluid.

 

fuel pump pressurizing the system.

ive had the car 3 years never heard that noise until last week.
is it something that would just start?
does it require any attention?

 

Front pads at 1 mm is not safe!! You need brakes now, dude.

In the RDX only low brake fluid or an ABS or booster problem will activate a light. The only indication of low pads is the screechers....or noticable deceleration by contacting concrete wall.

The intermittent sound might be the brake pad screechers, particularly if they are bent and not making good contact. The screechers should be in full contact at 1 mm. Or it's possible the inner pads (with screechers) have a bit more pad yet and he only looked at the outers (no screechers, easier to see). Obviously, the screechers will only make noise when brakes are applied, but could also be pressed into contact by lateral turning forces (the sound he heard). Get your brakes replaced first and see if the sound goes away.

With pads that low, your front rotors may need turned or replaced. Minimum rotor thickness is 26.0 mm and max run-out (wobble) is 0.04 mm.

Brake fluid absorbs moisture which causes corrosion; and boils and inhibits proper braking. Brake fluid should be changed about every 2 - 3 years. An 08 with 32k is certainly due for brake fluid flush. You will notice the difference fresh fluid makes. Use only Honda fluid.

 

thanks for the info.
up until visual inspection by mechanic,i had no noticable signs of brake wear.
vehicle is braking well,no warning sounds coming from the brakes.
might have just got to 1mm or perhaps he misread i have a bit more then 1mm.
at what mm reading do the brake sensors start giving you a warning sound sound?

front and rear pads are ordered, scheduled for monday delivery.il bring it in tues or wed.
when i asked my local mechanic if the brake fluid should be flushed he said no.
he could have made more money for the job.when i call to schedule brake job il ask him to get some honda fluid in case its needed.

 

The screechers are usually set to start sounding at about 2+ mm because 1.6 mm (about 2/32") is minimum for most state's inspection. The noise may start slowly and intermittently as a scraping or humming, then build to a continuous screech as the pad wears. (Everybody has heard a car stopping with screechers screaming away.)

But screechers are just simple bendable metal tabs on the inner pad that contact the rotor. A little bend forward or back can make them vary widely.

Also, inner and outer pads can wear unevenly because the RDX caliper pistons only push from the inside of the rotor. So your inner pads may be just reaching the screechers, while the outer pads are a mm thinner. That's not very unusual. It's also possible that the outer pads can wear down to the steel backing plate before the inner screechers are fully engaged. That's more common if the caliper is sticking, but it happens too. (Not an RDX thing -- almost all cars have floating calipers with inner pistons only.) It's a good reason though, why your mechanic should clean and regrease your caliper guide pins.

I would strongly recommend that you flush the brake fluid. At 3 years, it's near its limit for water absorption -- that's the difference between dry and wet boiling points listed on the bottles. But hey, I'm not gonna argue with your mechanic. Just look at your RDX Maintenance Journal:

 

some very good info.
i thank you for your input.
il take your advice on the fluid flush as well as cleaning and regreasing the caliper guide pins.