Uncontrolled swaying while driving

[biomech]

Hi All,

Had something strange happen this morning while driving to work.

First, I have a low mileage 01' 996 C2 (roughly 28K) which currently also has both PSM off and ABS lights on due to a bad MAF sensor. They've been on for a couple weeks now and I just haven't a chance to replace it yet.

I have about a 30 mile commute to work and during the drive this morning, I felt some uncontrolled swaying of the car while driving on the freeway between 60 and 80 MPH. At times, it felt as if there was a really high wind blowing against the side of the car pushing it around. Almost felt like a lost of traction or driving on a really wet road :o . Could this be a cause of the PSM being off? I checked all the tires and wheels and they all looked normal. The roads, freeways and weather were normal and shouldn't play into the cause.

Thanks in advance for any insight or opinions.

[biomech]

A little follow up on the above mentioned problem. I took the car out for a little drive during lunch and felt the handling/steering to be a little loose or slow to respond. It felt as if there was some slack between the steer wheel and the actual wheels of the car creating somewhat of a delayed response when I made turns. Most noticeable at lower speeds. Also, at lower speeds, it seem to take more of a crank on the steering wheel before the car started to respond to the direction of the turn. :drive: I've never had this problem with any of my vehicles, Porsche or other, so I'm sure my description of the problem leaves a little to the imagination. :help:

[k996c4s]

Your first post sounds like an alignment issue. Highways often develop indents where car and truck tires contact the road in the lane.... meaning there's a high spot at the lines, and low where the tires make contact, and also high between the tire tracks. An aggressively set or perhaps out of alignment condition can cause the pulling that you are experiencing. I had an RS America that liked to change lanes at high speed for that reason - very scary. However, after reading your second post, I'm not sure if that's it.

[lfe]

If this is a new problem, I would check my tire pressure. 35 and 40 series tires can be pretty low on air before they have any visible sign. But they sure will drive like crap.

[Izzy]

You should have the ABS codes read with Porsche System Tester, I do not think that has anything to do with the MAF. The MAF may or may not show as a CEL. Road ruts and tire pressures can all have impact, but the ABS light should not be on for an lean/rich mixture problem. Just want you to be safe in case you have an impending brake failure here.

[biomech]

Alright, problem solved :jump: . Thanks to everyone for chiming in!

After work today, I brought my 996 to an alignment specialist that was willing to stay late to do an alignment check on my car. He found 2 problems that caused the uncontrolled swaying I had. First, my forward right wheel toe was about an inch off causing the car to always want to pull to the right. Secondly, he found the right rear camber ecentric bolt (the technical term he gave the bolt as he pointed to it) was really loose causing the car to sway and fishtail everytime I hit any bump, small pothole or uneven road. The troubleshooting, alignment and safe drive home was worth every bit of the $150 I paid.

[tweety]

Cool that it's all fixed.

Before I got down to reading the solution, I was thinking that it was the steering. The second post of yours sounded exactly like when I had a steering box go out on a jeep I owned.

My question to you now is, how did it get so bad so fast without you knowing it or seeing wear on the tires?

[biomech]

:unsure: I did feel a little bit of a sway the previous time I drove the car but, it felt as if the problem escalated quickly. I'm guessing the camber ecentric bolt worked it's way from hand tight to loose within a few road bumps.

[demosan]

:unsure: I did feel a little bit of a sway the previous time I drove the car but, it felt as if the problem escalated quickly. I'm guessing the camber ecentric bolt worked it's way from hand tight to loose within a few road bumps.

Glad to hear the problem was diagnosed and fixed with the re-alignment. Kind of scary as to how that Camber eccentric worked loose so quickly. If you have had the car aligned recently ( before the latest fix) I would have a conversation with the shop that did the work and obviously didn't tighten the bolts to spec.

happy Motoring!! Demosan :cheers:

[Sboxin]

Alignment and ABS/PSM light -- Just added info on this issue...there is a sensor on the steering shaft that turns off the ABS/PSM when the toe is really bad. We just had this occur on a 986S. The Indi found the sensor and after the alignment reset the ABS/PSM...no problem for 2 weeks now.

biomech - did your light get turned off after the alignment?

Ed (Arizona) :cheers:

Hi All,

Had something strange happen this morning while driving to work.

First, I have a low mileage 01' 996 C2 (roughly 28K) which currently also has both PSM off and ABS lights on due to a bad MAF sensor. They've been on for a couple weeks now and I just haven't a chance to replace it yet.

I have about a 30 mile commute to work and during the drive this morning, I felt some uncontrolled swaying of the car while driving on the freeway between 60 and 80 MPH. At times, it felt as if there was a really high wind blowing against the side of the car pushing it around. Almost felt like a lost of traction or driving on a really wet road :o . Could this be a cause of the PSM being off? I checked all the tires and wheels and they all looked normal. The roads, freeways and weather were normal and shouldn't play into the cause.

Thanks in advance for any insight or opinions.

[biomech]

Ed,

Thanks for the heads up on the ABS/PSM light association with the alignment issue. I haven't ordered the MAF sensor yet so, would like to try a reset on the light first. How are the lights turned off or reset?

Thanks.

[gandrade1]

I have experienced the exact same situation this weekend on my '01 Boxster, which is perfectly described above as " felt some uncontrolled swaying of the car while driving on the freeway between 60 and 80 MPH. At times, it felt as if there was a really high wind blowing against the side of the car pushing it around. Almost felt like a lost of traction or driving on a really wet road ".

I am wondering whether this has to do with any alignment issues, which would surprise me since I have just bought new tires and asked for alignment and balancing. In addition I have no emergency lights on, everything seems fine and the car is otherwise great. What are the other "symptoms" of poor alignment?

Thank you so much,

Gustavo Andrade

[Izzy]

I had the same problem until I got a cup holder for my beer. Problem resolved, no more reaching for the cooler in the back seat, getting it open, etc.

Seriously, over time you will see uneven wear on the tires. But if you had alignement done recently, more likely than not is that it was either not done correctly, not done at all, or someone forgot the torque the hardware. I found that a tire place alignment can save money, but then you have to take it back to a specialist to get it right. So I just go to my local dealer and they always get it right.

[gandrade1]

Hahahah,

Thanks Izzy.

I will probably take it to the dealer then...Unless anyone alse knows any reputable shop in the NY / NJ area.

Gustavo