no-momma-wagon

So the SF Bay Area has had some good rain over the past two weeks. Twice durring this time, my Avant has emmited some very weird noises when driving through standing water. Keep in mind, we are not talking deep standing wader, but more like an above average puddle. Let's say .5"-1" deep. Bigger than normal, but nothing that should be a problem. I highly avoide large/deep areas of standing water due to various horror stories related to such things and warranties.

In both scenarios, a noise that soinds like scraping starts up after I go through the puddle. It sounds like metal on metal. I have stopped the car in both cases but see no visual clue of anything wrong. I get back in and the noise is gone. I thought maybe it was water hitting a hot part of the car, like exaust and burning off causing a strange noise, though last time I kind of "felt" the noise through the pedal.

Any idea? I am going to ask when I bring the car in, but thought I would ask here first as it's hard to reproduce.

DitchSurfer11937

theres no brake drying feature on these cars right?

S4iowa

of course it's almost impossible to reproduce for the dealer too. So that is likely to go no where fast.

Last time I had it happen was quite a while ago, maybe about a year now. It was related to engine speed. The last time it happened was on the interstate about 70 in the rain. I pushed in the clutch and the noise went away, got the RPM's up again and it came back.


My guess is some water is getting splashed up under the car by the water evacuation of the tires, and is getting caught on something and throwing a accessory or pulley out of balance?

It will go away like you said if you stop the engine... I guess water is draining from somewhere?

PetrolDave

Wrong - the B7 has brake drying but the B6 doesn't.

s4for5_TTfor2

I see no changes in the Service Manual between 04 and 07 brake wise ?

S4iowa

It's in the spec sheet....labeled as ESP with disc wiping

s4for5_TTfor2

Audi S4
S4 4.2 quattro 340 HP 6 speed
PricePrice
$48,610
EngineEngine-type
V8 front-mounted arrangement, 8-cylinder with Double Overhead Camshafts and two-stage variable intake manifold

Bore: 3.33 in.

Stroke: 3.65 in.

Compression ratio: 11.0 : 1

Displacement
4.2 L
Max Output
340 hp @ 7,000 rpm
Torque
302 lb-ft @ 3,500 rpm
Engine Management
Motronic 7.1.1: fully electronic, sequential injection, hot-film air mass measurement, drive-by-wire throttle control, mapped ignition with solid state high-voltage distribution, cylinder-selective adaptive knock control using four sensors
Emission Control System
Two close-coupled primary and two underfloor main catalytic converters; adaptive lambda control with two heated oxygen sensors before and two after the converter
Driving PerformanceTopspeed
Top speed is electronically limited at 155 mph
Acceleration 0-60 mph
5.3 seconds
Fuel ConsumptionFueltype
Premium unleaded 91 AKI / 95 RON recommended for maximum performance
City
13 mpg
Highway
20 mpg
Combined
15 mpg
Power TransmissionGearbox
6-speed manual transmission
SteeringFrontaxle
Four-link, upper and lower control arms, stabilizer bar, coil springs/shock absorbers (gas charged)
Rearaxle
Fully independent, trapezoidal link rear suspension, stabilizer bar, separate coil springs and shock absorbers (gas charged)
Brakes
Dual circuit brake system with diagonal split, Anti-lock Brake System (ABS), Electronic Brake pressure Distribution (EBD) and Electronic Stabilization Program; tandem brake booster
Steering
Maintenance-free rack-and-pinion steering with Servotronic electronic power assist
WeightUnladenweight
3869 lbs
VolumesLuggage Compartment Capacity
S4 13.4 / S4 Avant 27.8 cu ft
Tank Capacity
16.6 Gallons
Standard Equipments18" Seven-double-arm cast alloy wheels
Activated charcoal filter for dust and pollen control
Aluminum quattro® GmbH pedals
Audi audio Sound System
Audi symphony AM/FM/SAT* stereo with in-dash 6-disc CD changer
Backlit instrument cluster
Beverage Holder
Bi-xenon high intensity discharge headlights with automatic self leveling
Bi-xenon high intensity discharge headlights with automatic self leveling
Center armrest in front
Convex outer right rearview mirror
Dipping inside rear view mirror
Distinctive S4 aluminum-look exterior mirror housings
Driver's side exterior rearview mirror
Dual zone air conditioning with climate control
Dual-stage front airbags with occupant sensing for passenger side*
Electrically adjustable four-way lumbar adjustment for driver and front passenger seats
Electrically adjustable front seats
Electronic cruise control with coast, resume and acceleration features
Folding rear seat back
Front and rear floor mats
Full-size spare tire
Gray Birch wood decorative inlays
High-performance tires*
Leather gearshift ****
Leather-covered three-arm multi-function steering wheel with S4 logo
Load-through provision with ski sack
Lower Anchorage and Tethers for Children (LATCH) in rear seats
Multi-function display with check control and color display
Power adjustable, heated exterior mirrors
Power glass sunroof with slide-and-tilt functions and pinch protection
Power rear windows with power retention, "one touch up," "one touch down" and pinch protection
Preparation for mobile phone (Bluetooth®)*
Remote locking system
Retractable, high pressure headlight washers concealed in the front bumper
S4 Aluminum door sill trim
S4-tuned sport suspension
Seat belt warning light and tone
Servotronic®, speed-sensitive close-ratio power steering for sporty handling
Sideguardâ„¢ head protection airbags for front and rear occupants*
Silk Nappa leather
Silk Nappa leather with Alcantara inserts, Recaro® sport seats in front and back
Tire-pressure monitoring system
Trunk lid release control
Without roof rails<ul><li><a href="http://www.audiusa.com/audi/us/en2/new_cars/Audi_A4/S4/Model_Features/compare_models.html">spec page clicky</a></li></ul>

s4for5_TTfor2

Brake System
Front and rear ventilated disc brakes provide brake power consistent with driving performance. The power of the S4 is also restrained with a four-wheel Anti-lock Brake System (ABS) with Electronic Brake pressure Distribution (EBD) and Brake Assist, a system which automatically senses emergency braking and applies maximum available power boost to reduce overall stopping distance.

antiSUV

Under Safety and Security for the S4 Cab/Avant/Sedan: Antilock brake system with vacuum power assist, Electronic Brake-pressure distribution (EBD), hydraulic brake assist and disc wiping feature.<ul><li><a href="http://www.audiusa.com/etc/medialib/cms4imp/audi2/aoa/product_my08/pdf.Par.0003.File.pdf">Click to download brochure (23 pages)</a></li></ul>

S4iowa

my bad....EBD not ESP