Suspension Issue or oversensitive?? 997tt
Discussion
Hi All
Just need some advice from those who run a 997tt as a daily driver and knows its ins & outs.
I was driving down the motorway yesterday, the road surface was undulating and I was with the flow of the traffic in the outside lane.
For some reason I found the car was moving around a lot when it was going over the worse parts of the road surface even though the condition of the M40 is not really that bad, it was hard to keep the car in a straight line. It wasn't windy and i wasn't passing high sided vehicles that might cause this, it was though the suspension was struggling to cope.
I turned on the PASM and could feel an intermittent vibration through the floor, like a high speed judder! Ive not had PASM before, is this normal??
There is no vibration through the steering wheel and on some of the repaired motorway surface (the section where the road noise is really quiet and smoothe) the car is also smoothe and quiet.
Its a 2008 model with only 22k on the clock, the tyre pressures are as perc recommended and confirmed on the TPMS and the tyres are in good condition with plenty of life left in them (5mm all around). I had covered 300 miles in it over last couple of days and this issue was noticed towards the end of my journey.
Does this seem like the cars normal road manners and am I being over sensitive?
Cheers
r1
Just need some advice from those who run a 997tt as a daily driver and knows its ins & outs.
I was driving down the motorway yesterday, the road surface was undulating and I was with the flow of the traffic in the outside lane.
For some reason I found the car was moving around a lot when it was going over the worse parts of the road surface even though the condition of the M40 is not really that bad, it was hard to keep the car in a straight line. It wasn't windy and i wasn't passing high sided vehicles that might cause this, it was though the suspension was struggling to cope.
I turned on the PASM and could feel an intermittent vibration through the floor, like a high speed judder! Ive not had PASM before, is this normal??
There is no vibration through the steering wheel and on some of the repaired motorway surface (the section where the road noise is really quiet and smoothe) the car is also smoothe and quiet.
Its a 2008 model with only 22k on the clock, the tyre pressures are as perc recommended and confirmed on the TPMS and the tyres are in good condition with plenty of life left in them (5mm all around). I had covered 300 miles in it over last couple of days and this issue was noticed towards the end of my journey.
Does this seem like the cars normal road manners and am I being over sensitive?
Cheers
r1
Hmmm. I have a similar problem with a 997tt I've had for a month or so.
Mine was what I'd call 'squirming' at motorway speeds. Changed the tyres and had a 4-wheel alignment and this helped, in that it mostly removed that problem. But it's now light at speed... very light at speed, responding to every bump in the road and floating around a bit. It makes driving at speed a bit 'exciting'.
Had the geo done a couple of weeks back, but will have it re-checked just in case.
Haven't tried pressing the PASM button on the motorway yet, might try that next time to see what happens.
I'd get it checked out if I were you, maybe start with the geo?
Mine was what I'd call 'squirming' at motorway speeds. Changed the tyres and had a 4-wheel alignment and this helped, in that it mostly removed that problem. But it's now light at speed... very light at speed, responding to every bump in the road and floating around a bit. It makes driving at speed a bit 'exciting'.
Had the geo done a couple of weeks back, but will have it re-checked just in case.
Haven't tried pressing the PASM button on the motorway yet, might try that next time to see what happens.
I'd get it checked out if I were you, maybe start with the geo?
Thanks all for your replies,
Took it to the OPC I bought it from this morning and had a mechanic go with me on a road test, sure enough, the symptoms would not reappear!!! but they put it up on the ramps and plugged it in and there appears to be no problems at all.
I turned on the PASM in an attempt to reduce the kick back, it worked to a degree but it created an infrequent mechanical high frequency rumble which I can only think is the PASM working, (having never hd PASM before I was/am unsure)
This morning I had an OPC mechanic on board and took it down some local national speed limit back roads and the car behaved impeccably !!! typical.
The car was checked over and all was found to be in order.
As for the GEO, I'm going to wait until I have new tyres fitted and get it all done at the same time, the current tyres are in good order and appear to have no abnormal wear pattern, on smoothe road surfaces the car tracks straight and I have no vibration through the steering wheel.
Thanks again
r1
Took it to the OPC I bought it from this morning and had a mechanic go with me on a road test, sure enough, the symptoms would not reappear!!! but they put it up on the ramps and plugged it in and there appears to be no problems at all.
gd said:
Hmmm. I have a similar problem with a 997tt I've had for a month or so.
it's now light at speed... very light at speed, responding to every bump in the road and floating around a bit. It makes driving at speed a bit 'exciting'.
Your description is very accurate to what I was experiencing, I found it hard to track a straight line as it bounced off the bumps on the motorway.it's now light at speed... very light at speed, responding to every bump in the road and floating around a bit. It makes driving at speed a bit 'exciting'.
I turned on the PASM in an attempt to reduce the kick back, it worked to a degree but it created an infrequent mechanical high frequency rumble which I can only think is the PASM working, (having never hd PASM before I was/am unsure)
This morning I had an OPC mechanic on board and took it down some local national speed limit back roads and the car behaved impeccably !!! typical.
The car was checked over and all was found to be in order.
As for the GEO, I'm going to wait until I have new tyres fitted and get it all done at the same time, the current tyres are in good order and appear to have no abnormal wear pattern, on smoothe road surfaces the car tracks straight and I have no vibration through the steering wheel.
Thanks again
r1
My turbo had awful handling, I took it to 3 different dealers including my supplying dealer and they all said that's how these are supposed to drive, "nothing wrong with it" finally took it to porsche Guildford after threatening to reject the car via porsche GB and after close inspection they were horrified to see that another OPC had done the geo and was so completely off, I have a printout before and after- Hilerious, the handling still wasn't quite right and it turned out that it needed a new front differential. So maybe have them look at that!
ufo2 said:
My turbo had awful handling, I took it to 3 different dealers including my supplying dealer and they all said that's how these are supposed to drive, "nothing wrong with it" finally took it to porsche Guildford after threatening to reject the car via porsche GB and after close inspection they were horrified to see that another OPC had done the geo and was so completely off, I have a printout before and after- Hilerious, the handling still wasn't quite right and it turned out that it needed a new front differential. So maybe have them look at that!
Thanks.Were the problems similar to the ones we're describing? And did this sort out the problem in the end?
Definitely worth a trip to see Chris at cg. He has his doubters (including myself before). But on issues like this he WILL find the issue and you will drive away with the car handling as it should. Thats what he prides himself on he wont let you drive away with the car at less than 100%. Well worth the trip. And you can do it on your current tyres wont be a problem if you change them later. I also asked this before I had mine done.
PASM is always working remember - so you'd be switching it to sport, rather than 'on' which is way too firm, I think, for any roads in the UK bar the very smoothest and will tend to create almost the sensation of the car juddering - almost like running over cats eyes that are very close together (if you see what I mean).
Is it possible that that stretch of road + your driving style (PASM modifies behaviour based on that as well as road conditions I think) somehow fooled the sensors and perhaps made them firm up rather than do as you'd wish and soften up?
Pure speculation - somebody will be along shortly to correct me I'm sure!
Is it possible that that stretch of road + your driving style (PASM modifies behaviour based on that as well as road conditions I think) somehow fooled the sensors and perhaps made them firm up rather than do as you'd wish and soften up?
Pure speculation - somebody will be along shortly to correct me I'm sure!
My 997 Turbo never felt bad, but I took it to Center Gravity to have it checked over and to have the understeer eradicated. After many hours of checks and the geo' altered, the car feels even better. I've heard some horror stories about OPC alignments, I presume it's down to who does it on the day.
I'd recommend one of the independent good guys to have a look, they can alter it to your requirements if you wish, which I don't think OPCs will do.
I'd recommend one of the independent good guys to have a look, they can alter it to your requirements if you wish, which I don't think OPCs will do.
ufo2 said:
After close inspection they were horrified to see that another OPC had done the geo and was so completely off, I have a printout before and after- Hilerious, the handling still wasn't quite right and it turned out that it needed a new front differential. So maybe have them look at that!
My car has had 2 previous owners and only 20k on the clock when i bought it, I have no idea how its life before my ownership was, hence OPC route & 2 year warranty was a must for me, How would a front diff problem manifest itself in a a drive???
I took it to the OPC yesterday and they found nothing wrong with it. Its under warranty so if there was an issue with the diff' then it would be good to get it done.
I know it may in fact purely be me being over sensitive and Actus Reus comments are accurate too,
I will no doubt go to CG at some point but at the moment it is really good to see your comments and experiences, it gives me an indication of what possibilities there are.
Thanks again guys.
I don't remember the technical jargon but I think it was the sales manager at OPC Guildford does a lot of racing and after they did the geo on my car he rang me to say he still wasn't happy they the car drove or felt. Eventually they unplugged the diff and the handling was sorted and plugged back in handling awful, so a new diff sorted that problem. Before the diff was replaced my car felt like there was a constant cross wind on a motorway and it was almost making me fill sick. The balance was all over the place. It also pulled heavily to the left. (porsche bournmouth told me that there supposed to pull left? Load of crap) I also had an intermittent fault when starting the car the revs would rise to 6-7000 rpm but wouldn't do it all the time only at embarrassing times outside bars restuarants etc so it looked like I was revving it on purpose. They had it weeks and couldn't solve it. Also sometimes the power steering would all of a sudden cutout and a minute later come back. Same as when you get a kink in a hosepipe, couldn't fix that either. Became very dangerous. The dealer said that there's nothing wrong with the car but refused to buy or trade the car in because there's a fault, even though they say nothing's wrong. I ended up rejecting the car at a £15,000 loss after 4 months ownership. My car a week later was back on sale at an OPC. Just couldn't bare the thought of it cutting out on the motorway etc
The symptoms described do not sound correct for a 997 Turbo, which are renowned (by 911 standards) for their stability.
RWD 911s tend to be a bit more sensitive to road conditions, tyre pressures, blustery cross winds, etc, but tyres or geo are the normal culprits if it is an on-going issue.
OPCs will generally only set each corner to within recommended factory tolerances, and a lot depends on how recently their equipment has been re-calibrated and the analytical skills of the operator. This is why so many people recommend Chris Franklin, as he is so obsessive about detail, but there may be others.
It is true that, in recent years, most Porches do seem to have an odd bias towards the left. I wouldn't say they pull to the left, but 'hands off' that's the way they tend to move, irrespective of road camber, cross winds, tyre pressures.
RWD 911s tend to be a bit more sensitive to road conditions, tyre pressures, blustery cross winds, etc, but tyres or geo are the normal culprits if it is an on-going issue.
OPCs will generally only set each corner to within recommended factory tolerances, and a lot depends on how recently their equipment has been re-calibrated and the analytical skills of the operator. This is why so many people recommend Chris Franklin, as he is so obsessive about detail, but there may be others.
It is true that, in recent years, most Porches do seem to have an odd bias towards the left. I wouldn't say they pull to the left, but 'hands off' that's the way they tend to move, irrespective of road camber, cross winds, tyre pressures.
Hello ! 
If it was me R1, I would try to eliminate potential causes starting with the cheapest, ie geo. If you go the CG route, you know it's gonna be £200, well spent according to many, but not very clever if indeed it's the front diff. So I would try to find a local reputable rig to get some visibility on the current set up, paying particular attention to toe in this instance. Many places other than CG can offer that service for maybe £30/£50 and providing the operator is thorough and precise and possibly ballast the car to your preference, then you could publish the print out here to get opinions or simply learn very quickly what all the parameters mean and their implications on how the car handles/feels (it won't take long to learn in your case).
Then once you know the route cause you can either go to CG obviously or one of the many other operations that will tailor a geo to your preference.
My money is on toe being way out somewhere.
If it was me R1, I would try to eliminate potential causes starting with the cheapest, ie geo. If you go the CG route, you know it's gonna be £200, well spent according to many, but not very clever if indeed it's the front diff. So I would try to find a local reputable rig to get some visibility on the current set up, paying particular attention to toe in this instance. Many places other than CG can offer that service for maybe £30/£50 and providing the operator is thorough and precise and possibly ballast the car to your preference, then you could publish the print out here to get opinions or simply learn very quickly what all the parameters mean and their implications on how the car handles/feels (it won't take long to learn in your case).
Then once you know the route cause you can either go to CG obviously or one of the many other operations that will tailor a geo to your preference.
My money is on toe being way out somewhere.
Cheers Nick
I'll get the Geo done when I am back next, truthfully, given what people have been saying about CG it will be very interesting to see how the car is currently set up and how different it may/will feel when fettled by a professional.
The only thing that has prevented me from getting it done to date is having so little time in the UK, I'd rather be out driving the car than sat around all day waiting for a geo to be done however good the results will be afterwards.
I'll get the Geo done when I am back next, truthfully, given what people have been saying about CG it will be very interesting to see how the car is currently set up and how different it may/will feel when fettled by a professional.
The only thing that has prevented me from getting it done to date is having so little time in the UK, I'd rather be out driving the car than sat around all day waiting for a geo to be done however good the results will be afterwards.
r1flyguy1 said:
Cheers Nick
I'll get the Geo done when I am back next, truthfully, given what people have been saying about CG it will be very interesting to see how the car is currently set up and how different it may/will feel when fettled by a professional.
The only thing that has prevented me from getting it done to date is having so little time in the UK, I'd rather be out driving the car than sat around all day waiting for a geo to be done however good the results will be afterwards.
it will feel like a new car after cg finish with it.I'll get the Geo done when I am back next, truthfully, given what people have been saying about CG it will be very interesting to see how the car is currently set up and how different it may/will feel when fettled by a professional.
The only thing that has prevented me from getting it done to date is having so little time in the UK, I'd rather be out driving the car than sat around all day waiting for a geo to be done however good the results will be afterwards.
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