Bad Vibrations Part 2
07-22-2004, 05:37 PM
#1
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Bad Vibrations Part 2
Well just put new tires on the S, 285/45/19 Michelins, road force balanced and a complete 4 wheel alignment. I have the spec sheet showing before and after along with Porsche's published specs. My car was significantly out in the front for toe, camber and caster. It is now in spec.
Guess what, still have the rapid steering wheel vibration between 65 - 75 mph. It is most prevalent in the morning, but seems to subside after 20 mins of highway speed driving. Not completely however. I no longer believe it has to do with flat spotting over night, rather it is suspension related. I feel the culprit may lie in:
A) The control arm bushings (rubber) may be too soft or bad...But I have had this issue since day one and had resigned myself to the fact that it was tire flat spotting due to the weight of the Cayenne...so I don't feel the bushings could have worn out, rather that they are possible too soft and introduce too much play. Theory 1
or
B) The wheel pin bearings are the culprit. If they are loose, they could be responsible for this, but since they are not conical in nature, there is no way to tighten the fit. This seems to make sense to me...If they are not w/in spec, perhaps once they heat up and expand, the fit tolerance lessens, hence less vibration. I plan to post a pic of the Cayenne's front suspension schematic from the parts CD later.
Any thoughts??? I have explained this theory to the dealer and will be bringing the car back in next week...Boy this sucks!!! A 70K truck should not do this....
Guess what, still have the rapid steering wheel vibration between 65 - 75 mph. It is most prevalent in the morning, but seems to subside after 20 mins of highway speed driving. Not completely however. I no longer believe it has to do with flat spotting over night, rather it is suspension related. I feel the culprit may lie in:
A) The control arm bushings (rubber) may be too soft or bad...But I have had this issue since day one and had resigned myself to the fact that it was tire flat spotting due to the weight of the Cayenne...so I don't feel the bushings could have worn out, rather that they are possible too soft and introduce too much play. Theory 1
or
B) The wheel pin bearings are the culprit. If they are loose, they could be responsible for this, but since they are not conical in nature, there is no way to tighten the fit. This seems to make sense to me...If they are not w/in spec, perhaps once they heat up and expand, the fit tolerance lessens, hence less vibration. I plan to post a pic of the Cayenne's front suspension schematic from the parts CD later.
Any thoughts??? I have explained this theory to the dealer and will be bringing the car back in next week...Boy this sucks!!! A 70K truck should not do this....
07-22-2004, 06:17 PM
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Sorry to hear this...
Thank you for posting the tech drawings, I have been wanting this information for some time. My guess is that PAG is purchasing part a suspension from a supplier that is either out of spec or being built to a faulty spec.
Does your vibration change with road surface? I have heard that the vibration is less likely to occur on asphalt, it does not appear to make a difference on my truck though.
Keep me in the loop, people think that I am nuts for saying that this is a defectrather then a Tire or and Wheel problem.
Does your vibration change with road surface? I have heard that the vibration is less likely to occur on asphalt, it does not appear to make a difference on my truck though.
Keep me in the loop, people think that I am nuts for saying that this is a defectrather then a Tire or and Wheel problem.
07-22-2004, 06:32 PM
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rockitman, I know what you have suffered. Many of us (who own a Cayenne) have the same vibration issue. I believe the vibration free Cayenne to vibration Cayenne ratio is very close to 0. My neighbor's Cayenne and mine all have the same vibration problem at around the same speed period (around 65 to 75 MPH).
On another forum, a successful fix had been done. I had the same vibration issue on my 2002 Audi Allroad, and my Audi dealer did find the way to fixed the problem which took 2 sets of new Audi OE Allraod tires. Based on the experiment, I still believe problem should be on the wheel and tire.
Here is one of my theory: Due to the Porsche's spec., tire manufactures make Porsche OE N scale tires based on existing tire models. Due to cost effective of the production, a certain amount of tires will be produced. Porsche will take longer time to consume all the Porsche OE tires than other car makers does. Because, Porsche use Porsche OE tires only and other car makers use all use the non-Porsche OE tires. So, IF (may not be true, just a theory) a defect occur during the production of the Porsche OE tires, the defect will effect all the Porsches which use these tires. A long time will be needed to have the next revision of the Porsche OE tires, because no other cars use them. Therefore, change a new set of tires for now may not be able to solve the vibration problem, because the new set may still be the same defect tires from the same production line (time).
On another forum, a successful fix had been done. I had the same vibration issue on my 2002 Audi Allroad, and my Audi dealer did find the way to fixed the problem which took 2 sets of new Audi OE Allraod tires. Based on the experiment, I still believe problem should be on the wheel and tire.
Here is one of my theory: Due to the Porsche's spec., tire manufactures make Porsche OE N scale tires based on existing tire models. Due to cost effective of the production, a certain amount of tires will be produced. Porsche will take longer time to consume all the Porsche OE tires than other car makers does. Because, Porsche use Porsche OE tires only and other car makers use all use the non-Porsche OE tires. So, IF (may not be true, just a theory) a defect occur during the production of the Porsche OE tires, the defect will effect all the Porsches which use these tires. A long time will be needed to have the next revision of the Porsche OE tires, because no other cars use them. Therefore, change a new set of tires for now may not be able to solve the vibration problem, because the new set may still be the same defect tires from the same production line (time).
07-22-2004, 07:44 PM
#5
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You know I have read all this but you (Chris) and I have cars of similer age. I too had vibration, and it took them 3 times to get it right but now I have none.
I look at all thats written and it points at wheels. They are either badly contructed with very small sweet spots or the tires are bad. Or even a combination which makes it a black art to balance.
I cannot buy the suspension part involvement because mine was cured. Its the dealers lack of expertise in my opinion, and bear in mind this is not on all Cayenne's although reading the boards may imply this.
I look at all thats written and it points at wheels. They are either badly contructed with very small sweet spots or the tires are bad. Or even a combination which makes it a black art to balance.
I cannot buy the suspension part involvement because mine was cured. Its the dealers lack of expertise in my opinion, and bear in mind this is not on all Cayenne's although reading the boards may imply this.
Last edited by mudman2; 07-22-2004 at 07:59 PM.
07-22-2004, 09:34 PM
#6
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I don't buy the old N-spec tire theory. The 19" Diamaris are not Porsche spec, since they are not 275's...They are 285. I don't think they are the wheels either...The tech said they needed very little weight adjustment to road force balance and are perfectly straight...I also disagree that it is incorrect use of the road force balance machine. The same tech did my wheels on the GT3...No problems...I really believe there is a suspension component flaw, possibly in design that is responsible. It would be interesting to note whether people who run 18's have the vibration or is it more common with people who run 19's and 20's. I have a very good relationship with my SA. I keep the gears greased well so I know he will go to bat for me and get to the bottom of this annoying issue. If you can buy a $30K Blazer and have no vibration, then there should be no reason a $70K truck should have it...
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07-23-2004, 01:58 AM
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rockitman,
In your suspension theory you are forgetting two more variables/components:
springs and shocks.
If either is too soft for wheel size/weight => you MAY get resonance vibration at speed segment, you are discribing at 55-65 mi/h, disappearing with speed at 80 mi/h and decreasing with warming tires after 20 min. drive...
In your suspension theory you are forgetting two more variables/components:
springs and shocks.
If either is too soft for wheel size/weight => you MAY get resonance vibration at speed segment, you are discribing at 55-65 mi/h, disappearing with speed at 80 mi/h and decreasing with warming tires after 20 min. drive...
07-23-2004, 05:11 PM
#9
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Originally Posted by ozr
rockitman,
In your suspension theory you are forgetting two more variables/components:
springs and shocks.
If either is too soft for wheel size/weight => you MAY get resonance vibration at speed segment, you are discribing at 55-65 mi/h, disappearing with speed at 80 mi/h and decreasing with warming tires after 20 min. drive...
In your suspension theory you are forgetting two more variables/components:
springs and shocks.
If either is too soft for wheel size/weight => you MAY get resonance vibration at speed segment, you are discribing at 55-65 mi/h, disappearing with speed at 80 mi/h and decreasing with warming tires after 20 min. drive...
07-23-2004, 05:13 PM
#10
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Originally Posted by ozr
If either is too soft for wheel size/weight => you MAY get resonance vibration at speed segment, you are discribing at 55-65 mi/h, disappearing with speed at 80 mi/h and decreasing with warming tires after 20 min. drive...
07-23-2004, 06:38 PM
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Well, keep us informed. I think I can live with it as it goes away around 80 ;-) and it's not that bad... Still, for the money you think we wouldn't have this problem....
07-23-2004, 08:53 PM
#12
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Originally Posted by JFScheck
Well, keep us informed. I think I can live with it as it goes away around 80 ;-) and it's not that bad... Still, for the money you think we wouldn't have this problem....
Edit: I just noticed you have air suspension..and you get vibration too??? That helps to discount the theory that it is spring/shock related then...hmmmm
09-13-2004, 05:37 PM
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Vibrating steering wheel after new tires
Sorry to bring this one out of the past.
I never had any vibration issues with my S for 18,000 miles on the stock Continentals (275/45 R19). Never mattered how fast or slow I was going.
Just put on 4 new Pirelli Scorpion M+S (285/45 19) tires and noticed soon after that I had the infamous vibration problem. Whatever causes the Cayenne to vibrate, was just pushed over the edge with these new tires. I find it hard to believe they were not balanced properly.
What should I do? I can just see the dealer telling me that it's not covered under warranty because I didn't go with the recommended tire type or size.
The steering begins to vibrate at ~65mph all the way to ~85mph. I didn't feel comfortable going more than 85 with a vibrating steering wheel. I intially thought these tires had the overnight --> warm-up period issue but like Rockitman, found this wasn't the case.
I never had any vibration issues with my S for 18,000 miles on the stock Continentals (275/45 R19). Never mattered how fast or slow I was going.
Just put on 4 new Pirelli Scorpion M+S (285/45 19) tires and noticed soon after that I had the infamous vibration problem. Whatever causes the Cayenne to vibrate, was just pushed over the edge with these new tires. I find it hard to believe they were not balanced properly.
What should I do? I can just see the dealer telling me that it's not covered under warranty because I didn't go with the recommended tire type or size.
The steering begins to vibrate at ~65mph all the way to ~85mph. I didn't feel comfortable going more than 85 with a vibrating steering wheel. I intially thought these tires had the overnight --> warm-up period issue but like Rockitman, found this wasn't the case.
09-13-2004, 05:41 PM
#14
Moderator !x4
Hey BenLee
In the hands of some techs the Road Force Balancing needed is like a black art. Its taken me 3 times to get tires balanced in the early days. Now my dealer gets it right everytime. Take it back to the dealer.
In the hands of some techs the Road Force Balancing needed is like a black art. Its taken me 3 times to get tires balanced in the early days. Now my dealer gets it right everytime. Take it back to the dealer.
09-13-2004, 06:03 PM
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[QUOTE=BenLee]Just put on 4 new Pirelli Scorpion M+S (285/45 19) tires and noticed soon after that I had the infamous vibration problem. Whatever causes the Cayenne to vibrate, was just pushed over the edge with these new tires. I find it hard to believe they were not balanced properly.
QUOTE]
Hard to believe or not, it is most certainly a tire balance issue. You didn't have vibration before new tires and nothing else was changed, correct? This really narrows it down to the tires.
It sounds like you did not purchase them from your dealer. Take the car back to whoever you bought the tires from and tell them the tires are not balanced. The tire seller needs to correct this, not the dealer. I am willing to bet that most vibration problems attributed to the Cayenne are tire balance issues anyway.
QUOTE]
Hard to believe or not, it is most certainly a tire balance issue. You didn't have vibration before new tires and nothing else was changed, correct? This really narrows it down to the tires.
It sounds like you did not purchase them from your dealer. Take the car back to whoever you bought the tires from and tell them the tires are not balanced. The tire seller needs to correct this, not the dealer. I am willing to bet that most vibration problems attributed to the Cayenne are tire balance issues anyway.