P13TR0 Posted February 16, 2007 Report Share Posted February 16, 2007 Hi Tony... I'm Back I had 4 new Pilot Sport 2's put on the car this weekend, and since then I have had the following problem. (This problem may have been there for several weeks, but could have been disguised by the nsf -ve camber wear on my old set of tyres which was causing increased tramlining). The car feels great on country roads, but I got on the motorway for a long run, and at what appears to be random times, the steering goes light and vague. This is not tramlining as I know it!! I have had the car from new and covered almost 30K miles so I know it used to feel a lot more planted than it does now at speed. The thing I dont understand is that one minute it's fine and the next its all light and fluffy. Its almost like the dead zone of the steering input increases for a moment and im on a patch of ice. Things I have considered: 1) Warped wheel 2) One or more wheels not balanced properly 3) Worn suspension parts - shocks, bushes etc... 4) Reduced front toe angle (during the laser alignment I had done 3k miles ago the guy changed my toe angle from 11 minutes to 0.05 minutes - which is still within BMW spec for my car) Anyone have any ideas? This is driving me crazy..... thanks in advance. Quote Link to comment Share on other sites More sharing options...
jon Posted February 16, 2007 Report Share Posted February 16, 2007 What tyres were on before? Different boots have highly different reactions and feel to different road surfaces. Quote Link to comment Share on other sites More sharing options...
Tony Posted February 16, 2007 Report Share Posted February 16, 2007 I agree with jon. If you can detect an alteration in the cars handling from an addition of a product (tyres) in your case, then the criminal must be the product? If the car were in my centre now i would...... 1: Test the tyre pressures 2: Check the rear coil/s have not snapped (common problem) 3: Set the toe back to +11' despite the camber position. Then test drive. Quote Link to comment Share on other sites More sharing options...
P13TR0 Posted February 16, 2007 Author Report Share Posted February 16, 2007 Hi, I had Bridgestone Potenza's on ther previously. Michelin Pilot Sport 2's are OEM fitment, and I know many people who run them on 330 coupe's without problems like mine. I checked rear springs after seeing the M3 thread. They are fine. My Tyre pressures are spot on 38 psi front and 44 rear as per door pilar and Michelin spec. I think it is eaither the toe angle or the front control arm bushes??? Thanks for your replies Quote Link to comment Share on other sites More sharing options...
jon Posted February 16, 2007 Report Share Posted February 16, 2007 Out of interest, which potenzas? Quote Link to comment Share on other sites More sharing options...
Tony Posted February 16, 2007 Report Share Posted February 16, 2007 Out of interest, which potenzas? Good question.... The "Potenzas" are compound specific.. Quote Link to comment Share on other sites More sharing options...
P13TR0 Posted February 17, 2007 Author Report Share Posted February 17, 2007 RE040 factory fitment Quote Link to comment Share on other sites More sharing options...
jon Posted February 17, 2007 Report Share Posted February 17, 2007 The thing about the 040s is they've extremely stiff sidewalls meaning changing to any other tyre does make the car feel a little more dead. I'm not saying this is the only cause of your problem but it's worth bearing in mind 040s are very lively tyres. MPS is great rubber (and you'll find them mind blowing once the roads warm up and you can get some heat into them) but not quite as darty. That's about all the good i'll ever say about the 040s. Shockingly bad tyres in the cold and damp. Quote Link to comment Share on other sites More sharing options...
P13TR0 Posted February 17, 2007 Author Report Share Posted February 17, 2007 Totally agree with that. Tread wear was really bad too! These MPS are giving unbelieveable amounts of grip, and you can feel exactly the point when they are about to break away. Wish I could get this strange loose/ light/ vague steering problem sorted out though. I think it could be the control arm bushes (common problem) but also wondering if one or more wheels was not properly balanced when the MPS were put on. Other strange thing I have noticed is that the pilot sports have 1mm less tread depth on the inner tread groove than on the rest of the tyre. I assume this is by design, as all 4 tyres are brand new and have the same characteristic. Quote Link to comment Share on other sites More sharing options...
Tony Posted February 17, 2007 Report Share Posted February 17, 2007 Totally agree with that. Tread wear was really bad too! These MPS are giving unbelieveable amounts of grip, and you can feel exactly the point when they are about to break away. Wish I could get this strange loose/ light/ vague steering problem sorted out though. I think it could be the control arm bushes (common problem) but also wondering if one or more wheels was not properly balanced when the MPS were put on. Other strange thing I have noticed is that the pilot sports have 1mm less tread depth on the inner tread groove than on the rest of the tyre. I assume this is by design, as all 4 tyres are brand new and have the same characteristic. Can i ask these questions... When driving straight is the steering wheel central? and does the car have EPS? Quote Link to comment Share on other sites More sharing options...
P13TR0 Posted February 18, 2007 Author Report Share Posted February 18, 2007 Yes the steering is central, although there is a little play between 12 and 11 o'clock. The car has dynamic stability control which monitors a load of things to keep the car going in a straight line. What are you thinking? Quote Link to comment Share on other sites More sharing options...
Tony Posted February 18, 2007 Report Share Posted February 18, 2007 Yes the steering is central, although there is a little play between 12 and 11 o'clock. The car has dynamic stability control which monitors a load of things to keep the car going in a straight line. What are you thinking? Most EPS systems have "centre weighting" This encourages centering and the steering to stay central... Also some assisted systems lower the assistance as the vehicles speed increases otherwise @70mph the smallest steering action would over-steer. Quote Link to comment Share on other sites More sharing options...
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