adroadster

Often times when I brake and get to low speeds ( 5mph and below ) I hear a rumbling noise from what seems to be the engine bay. It sounds almost as if fluid is bubbling.

I have had a tranny flush, and brake fluid has been flushed twice but the noise persists.

It does not occur all the time. Almost never when the car is driven first thing in the morning. Usually occurs after the car has been driven for at least 30 minutes(collective for the day).

Any ideas?

cheshirecat79

iTrader: (9)

Does it only happen while moving? Will the sound persist if you pump the brakes while at a full stop?

If you don't break and coast to a stop, does the sound not happen?

adroadster

1. It only happens while moving
2. No sound if I pump brakes while at full stop
3. If I coast to a stop, there is no sound.

It is only when I apply the brakes at the very slow speeds.

cheshirecat79

iTrader: (9)

I wonder if it could be some kind of rotor issue.

adroadster

Odd, to me somehow I cant seem to associate it with a rotor. But ...

Originally the car had extremely harsh braking. The brakes were pulsating. Took it to dealer...they "did their stuff" but the problem persisted. Long story short, I ended up replacing only the front left rotor. Braking improved dramatically and the brake "pulsing" went to a minimum. I was told later that the other rotor has been "slightly" warped.

Is that my problem you believe?

cheshirecat79

iTrader: (9)

That what I was thinking, some kind of resonance that only happens at lower wheel revolutions. Is it possible you can record a video of the sound? Not sure how audible it actually is.

adroadster

I could try, but it will be difficult as it doesnt occur everytime. If recording audio is not possible, I will try to listen closely to provide the best description of it.

And thank for you for all your help cheshirecat

cheshirecat79

iTrader: (9)

I don't really think I'm helping much, but somehow we might be able to isolate the problem.

adroadster

Update:

Drove around this morning, no problems. Left work to go to lunch and at EVERY stop, I heard this "fluid' noise. It was pretty bad. Sounded like some fluid was being drained and everyone around could hear it. Decided it would be perfect opportunity to record the noise. When I headed home and had my "recording device" (phone heh), it made no more noise.

I went ahead and checked my fluid levels to see if this information could be of any assistance as I arrived home(had waited about 15 minutes). All my my fluids I could check were at the very max level indicated. My power steering fluid was about 1/3 of an inch over the "Max" level.

Hopefully some of that information can help us find out what the problem is?

adroadster

Update:

Checked fluid levels this morning again. Everything was still at the max. Power steering fluid was again over the max(this time for Cold Max). Had enough light to check by brake fluid, and it appeared to be over the limit as well. It was almost completely full except for what looked like an air-ish bubble.

Possibly the culprit?

adroadster

Anyone?

I really dont wish to go to the dealership ( for the third time ) just for them to "do some tests" and charge me for it.

my05350z

sure a third visit wouldnt get you a new car under lemon law? lol, just a thought

adroadster

I dont think it would, since they never really heard the problem. So never could fix it.

Just as an update incase anyone was actually reading this thread...

Took it to the dealer for the 3rd time yesterday. They couldnt hear the sound, had to drive down there and replicate it. Ended up being able to re-produce the sound for the technician. He was fairly stumped as well.

Long story short for anyone who may run across this problem. The only "fix" that so far has worked, was draining ALL the fluids in the car. Draining the fluid from coolant, power steering and brake was apparently not the issue. Im not sure which other fluids there are, but it was one of the others.

adroadster

Problem still persists. Planning on going back to the dealer for the fourth time. Would a lemon law apply?

If any of you have any experience or input I am all ears. This was created as a thread looking for help, not a diary.

LAKERSFAN

iTrader: (12)

wish i could help but ive never heard of anything like this......

gl

Sean

sure it's fluid? warrped rotors would make sounds in the situations you described.

adroadster

The sound seems to be that of a fluid and I find it hard to believe it is a mechanical issue.

Despite what I may think, is it possible that the warped rotor would have a similar sounding effect? I had noticed that the front left rotor of the car was warped pretty bad several weeks ago(car was puchased second hand), but was replaced with a brand new one. The front left was also deemed "slightly warped" but to an extent that was believed to be "negligible, and not needed for repair"

My girlfriends dad, whom used to be a techinician for many years of his life, told me that it was simply a common sound from sports cars. Has anyone experienced anything like this?

Sean

the fact that I thought it was rotors, and you had issues with them already (the car is a 2007 and it's had a rotor issue already?) makes me confident it is the rotor.

adroadster

The car is 2003.

It was purchased at 48,000 miles.

Still believe it is a rotor issue?

adroadster

Still occuring. This is annoying.

Ive noticed it happens more often when the car is warm.

(Rained here in socal and I experienced it zero times yesterday. All warm today and it was back)