Nicole

So, I've had incredible pain from my sciatic nerve since last weekend's fun drive; not the first time after driving the 928 for more than an hour or two. I discussed this with my doctor, and she thinks the strong back pressure from the gas pedal causes this. She basically told me that if I can't reduce that back pressure, I'd have to get rid of my beloved shark - or live with the pain.

I guess I'll study very hard how the throttle cable is routed, and what springs it moves. Maybe there is a solution. I know that some of the German owners have less back pressure on their 928s. There has to be a reasonable way - I just hope I won't have to take half the engine apart to do this.

Meanwhile I got stranded with the Saab tonight. Drove it to Walnut Creek this afternoon without incident, Parked it in a parking garage, and came back after three hours. Engine started with very loud rattle, and I could feel a vibration on the timing belt cover. Shut it down and had it towed... Wonder what that's going to be. Timing belt and tensioner are only 3k miles old. Also had an exhaust repair very lately.

Some days I wonder, if I should not rather get one boring but reliable newer car...

ColinB

Keep the faith. There will be some way to reduce the throttle pedal pressure.

CB

GUMBALL

I have had the same problem occasionally, and it is always due to something that I have done to throw out my back. I am not being flippant, because I understand how painful it can be, but an adjustment from a good chiropractor solves the problem almost immediately (or, it does for me) My advice..find a new chiropractor.

Charley B

Sciatic and other lower back pains from driving are nearly always caused by body positioning as opposed to pedal effort. In other words let's say it requires 10 lbs. of pressure to press and hold your gas pedal. In one postion you could manipulate the pedal for hours with no pain. In another position, 20 minutes could find you in excruciating pain. Positioning is critical.
Sometimes the solution is as simple as adding a small pillow behind the small of your back. Usually, however, back padding exacerbates the problem. Each individual is different. If your seat has lumbar support, try the lowest (least) setting available. Then adjust the seat for the optimum distance from the gas pedal and lastly adjust the seat back for distance from the steering wheel. We often set the fore and aft adjustment to accomadate the steering wheel distance and the pedal ends up too close or too far and we compensate with a less than ideal body position. That's why it is important to set for pedal distance first and then adjust the seat back for steering wheel distance.
It also helps to adjust the seat as high as possible so that there is no effort being made to lift the foot and lower leg while driving. A little trial and error can make a big difference in you comfort level.
Lastly, get in the habit of using your cruise control and change the position of your foot every 10 or 15 minutes. Any time you are traveling more than one block at more than 25 MPH is appropriate for cruise control. Unless, of course, you're running through the twisties.

Nicole

Thanks, Charley! I've tried different positions, but haven't found one that does not give me trouble after a while. Maybe I'll take a class on seat adjustment next time I see you...

rixter

Nicole,
I also recommend seeing a chiropractor,
do your seats have lumbar support?

ew928

Nicole,
Have you tried adjusting the throttle pedal yet?
3 position mounting holes on the floor. 2 bolts fasten the base of the pedal to the floor.
I forgot what size bolts. I'd been cramping my lower leg till I got advised to check for throttle pedal adjustment.
I have one of those memory foam lumbar pads since my 8-way seats do not have lumbar adjustment.

Bill Coleman

I know that feeling. Seems like a constant stream of problems with my cars recently. You know it's bad when your most reliable car is a '91 Accord w/123k+ miles on the odometer.

Erling G-P

With the acquisition of my 928, I now have two old cars as per my sig. I'm hoping they will at least be considerate enought to alternate between breaking down, but wouldn't surprise me one bit if Mr. Murphy will have it otherwise...

Nicole, fingers crossed you find a solution to the problem !!

Cheers,
Erling

shaaark89

hi nicole,
the twin screw setup has virtually no throttle pressure

Mike Frye

Nicole,

My gas pedal used to be much harder to push, and occasionally would stick at about 1500 rpms with the clutch pushed in at a light.

When I looked at the assembly, I found that the circlip was missing and one of the two bushings that are supposed to be inside of a ring had partially backed out. There are two bushings that are supposed to face each other and then are held in place by a circlip. Or maybe your issue is as simple as some lube in the bushings to free things up down there.

Mine is much more responsive and requires very little pressure. As previously mentioned, I think there's also some adjustment that can be done if the angle is the problem. Since you plan on checking the cable routing, I'd start with the pedal assembly.

I think in a previous thread you mentioned that you have to keep your seat forward because you're, well, less than the 6 foot height these cars seem to have been designed for. Maybe some blocks on the pedals will fix the angle of your leg to make it more comfortable?

I hope you figure it out. Good luck.

BrianG

Nicole, I AM a chiropractor, and have had the same issue as you are having. For me it took 2 changes.

1. alter the seat position.especially the seat pan. My ideal position was with the seat pan tilted much lower in front than I was used to..... so far, in fact that it felt wrong.

2. remobilization of the lumbosacral junction. The mechanical complex that includes the lowest disc and the 2 S/I joints often becomes dysfunctional over time.... especially for those with desk jobs, due to the prolonged sitting. A series of treatments of spinal manipulation can resolve this issue. You will likely not see significant change in a longstanding situation like this before 6 treatments. If it is working you will see notable changes by 12 treatments. Go to someone that X-ray's it before they treat.

dr bob

Nicole-

One thing I've been thinking about as I consider seat recovering is adding a 1/2" or maybe 3/4" pad to the middle of the seat bottom. Blasphemy from the purists I know... I need the extra height to lessen the squeeze from the bottom bolsters, essentially flattening the seating surface side to side anyway. Karen complains about the seat bottom to the point where she doesn't like to ride in the car, so I'll probably do both front seats to match. She's used to the wide flatter thrones in her 4-Runner, and thinks the Recaros are junk in comparison. Comparison-- pre-GM, Saab used a Scheel-designed ortho seat that was "just right" for my sensitive butt. Hours of touring with no complaints at all from me or passengers. 290k on the car, I had to demo to the Ford guy how much better the very well-used Saab seats were than any of the "sport seat" offerings they had. I ended up doing a lot of adjustments to the seat padding on the Explorer sport seats before they were right. I'd tried the standard seats on an extended trip in a rental, and knew after an hour that they were just unacceptable. Taking the seats apart isn't that big a chore, and you'd be amazed at how much a little adjustment will help. How do your current Saab seats compare with the 928 seats?

borland

Nicole,

Most of the throttle back pressure on the automatics, is due to the borden cable tension. That's the cable that connects to the automatic transmission.

You can significantly reduce the throttle back tension by disconnecting the borden cable or slacken the tension. That's done at the throttle linkage console on the intake manifold. Doing this will not impair the driving function. The transmission will still downshift under throttle, just not as quickly.

I have mine (90' S4) set looser than the WSM recommends. I like it that way and it also reduces the wear on the cable. I had it set that way even before I installed the GTS Kickdown mod.

See WSM Volume 3, page 37-115 for adjustment procedure.

heinrich

Agreed ... I have lived with it for over 20 years and the seat and FRONT seat height are the most important. If your legs hit or are resisted by the front edge of the seat, you will aggravate your sciatic nerve (at least this is the case for me. I lower my seat front to where it merely supports my legs at rest. No problems. I do find the old 928 seats less than aptomal, because they channel my left thigh to the right of where I need it to be. With the 996 sport seats they seem to allow a wider left leg position. Nicole, my good karma thoughts are with you. Don't worry. You will be fine. Your cars will be fine.
Heinrich