Need a bit of help from the Saab Gods. Wife had a problem with the '97 900 SET 5sp today. I met her roadside and swapped cars so she could get to work, then drove the car back to the house.

Symptoms are as follows; terrible grinding/vibration from front left (driver's) wheel area. Is not engine RPM dependent. Is wheel RPM dependent. Frequency increases with wheel speed. Full throttle load eliminates the noise completely. Part throttle makes it appear mildly. No throttle coasting makes it really loud and nasty. While coasting it doesn't matter whether the clutch is in or not, or whether it is in gear or not. No brakes while coasting is at full loudness. Part brakes under coasting and it starts to go away. Full brake load and it disappears completely. When I turn hard to the right, loading up on the left front tire, it becomes more pronounced. When I turn hard to the left, unloading the left front tire, it vanishes briefly before centering the wheel again.

Any thoughts? The sound reminds me of really bad wheel bearings with no grease. The wife did submerge the front end pretty good yesterday while on the interstate when she hit a huge mass of standing water. Since then the temps have plumetted to well below freezing.

Sounds to me like you have either a frozen (stuck) caliper puck. Since you did say it is brake dependant it would make sense unless you lost part of a brake pad which I have done before and it was a horrible noise.



I would seriously pull the wheel off and have your wife pump the brakes and watch the caliper to see if it extends and retracts like it should.


Also check the dust shield behind the rotor to make sure that when your wife hit the water it did not bend it up into the rotor. That can make a loud grinding noise too.

I've had stuck brakes on both rears (LH last year, RH this year). Try doing a 40-0 mph brake test. If there's a lot of vibration and grinding, this is probably the issue. Moisture (like when the front end of your car got submerged) causes corrosion on the rotors and calipers, which can make the brake pad or whole caliper sieze.

Edit: The solution to this would be to slip out the brake pad and remove the rust around it with a steel brush. Get as much rust as you can off, and see if that helps. That would fix a frozen pad, but if the whole caliper is stuck then you need to disassemble and clean/replace the caliper. It will be a while before all of the grinding (while braking) goes away because teh rust has to be ground off the rotor.

Thanks both of you for the advice. My inclination is to remove the wheel and see if I can determine what the problem is visually. Problem is that it's about 0 degree windchill right now and my driveway is 3" thick with solid ice. Sounds like a poster moment for how not to jack up the car. Hopefully things will thaw out at some point soon and I can check on this myself.

I hate to tell you but it sounds like the dreaded diff noise under trailing throttle. Just replaced the transmission in my 95 900SE Turbo 5 sp for the same reason.

Could it be ice build up on the inner wheel rim? I had vibes on both my Audi and Saab today because of the build up from the snow storm we had yesterday.

It is much more about the grind and much less about a vibe. Imagine both pads missing and the pistons applied directly to the rotors at interstate speeds to get a feel for how loud of a grind I'm talking about.

Sounds like it could be your wheel bearing,

Sounds like it could be your wheel bearing,
I agree with this assessment, to an extent - if the brakes lock and prevent rotation, then no-noise.....
But wheel bearing noises usually start out fairly mild, and then become worse/louder as the miles pile on...
Sounds to me as if something rotating just broke.....the differential or a CV - a visual insepction is necessary..
The car may stay in place while being jacked up on this ice - (if the area is flat) - have plenty of wood blocks handy..and some carpeting , and heavily insulated cover-alls...and plenty of hot coffee, and some help.....and Arctic survival skills...

It might be a warped disc - if she hit the standing water while the brakes were hot then it may have warped the disc (happened to me once - not best impressed at the time!!)

Sounds like it could be your wheel bearing,

That was my intitial thought as I've had bearings go on a different car (over a period of months) and when they got really bad they sounded much like this. If the bearing was somehow compromised and water was introduced, then froze solid, then was driven with water contaminated grease while frozen, it seems like they could fail pretty quickly. Oh well, driveway has gone from 3" of ice to 1" of ice so I should be able to pull some things apart and check out what's going on soon.

Just an update......

Turns out the wheel bolts worked themselves loose. Had done a tire/wheel change to snows with proper torque wrench on preceding day. Have been advised that combination of anti-sieze, hot wheel/ice cold puddle, and lack of re-torque at 25 miles (as specified) all contributed. Wheel was ruined as the bolt holes were worn out-of-round. Got a decent used one at the local indy mech and am as good as new.

Wow, to think that was from the wheel. :o At least you are golden now. Lucky the wheel didn't fly off while you were running.