Strange Bumping Issue

[Bliky]

So, very recently my car has developed a problem than I just don't know how to get rid of. As a preface I did just install rear Koni Shocks and Steeda springs but this problem was happening before all of that went on.

Basically, if my car has sat for a little and I go to drive off the road feels REALLY bumpy... Almost as if i'm driving over a bumpy dirt road. The weird thing is that it goes away after I drive for a while but if you really try and feel for it, its still there. It's almost as if it practically goes away after part of the car is warmed up but not fully... At highway speeds it's pretty much not noticeable but if the cars been sitting and I do some city driving the car feels like its bouncing around like crazy.

The tires are new and after my suspension mods I had it aligned and all 4 tires balanced. They all have proper air pressure in them and I even pulled my spark plugs to check them... I have no idea what this is >.<

My Dad and a friend of mine seem to think it might be the DCT since it isn't warmed up all the way until I start driving around and this problem did start showing itself when it started getting REALLY cold here in Jersey.

I've even left the car running for 10 minutes before driving it and it makes no difference at all. So weird.

[Pendarus]

Soft compound tires, and cold weather? Might be flat spotting from sitting. Goes away once the tires are warm?

[Elizabeth]

It is the tires. From sitting they get a 'flat spot' which in cold weather takes awhile to go away.
I suggest adding a few extra pounds of air in each tire in cold weather to reduce the problem.
Also, some tires are much worse with this issue than others...
In cold weather nearly all tires have this to at least a minor degree.
Your new shocks may be making it way more noticable.. being a little stiffer too.

One minor way to lessen it is to drive in a tight circle a few times. The flat spots then stop being in the same place as the tires move a different distance in the circles. So the bumps are 'spread out' instead of all four at once.

[cobie56]

i agree.. tires... i often leave my cars parked in the garage for weeks at a time w/o using them (heated garage) and when i do use the car it takes several miles to get the 'bump' out
happens w/ the oem contis and now w/ dws contis as well as the good years on another car.

[Bliky]

Originally Posted by Pendarus

Soft compound tires, and cold weather? Might be flat spotting from sitting. Goes away once the tires are warm?

I'm like 90% sure it goes away after the tires are warm, assuming it's the tires. Unfortunately, it's hard to tell on almost all Jersey roads since they are bumpy to begin with -.-

Originally Posted by Elizabeth

It is the tires. From sitting they get a 'flat spot' which in cold weather takes awhile to go away.
I suggest adding a few extra pounds of air in each tire in cold weather to reduce the problem.
Also, some tires are much worse with this issue than others...
In cold weather nearly all tires have this to at least a minor degree.
Your new shocks may be making it way more noticable.. being a little stiffer too.

One minor way to lessen it is to drive in a tight circle a few times. The flat spots then stop being in the same place as the tires move a different distance in the circles. So the bumps are 'spread out' instead of all four at once.

Would the fact that the car mostly sits on an incline in my driveway? Nothing too steep but it's a bit of an incline make it worse? Also, the fact that it got worse when I installed the shocks make sense.

When I checked the pressure the other day they were all between 32 and 35 PSI. I'll make sure tomorrow they're all at 37.

Originally Posted by cobie56

i agree.. tires... i often leave my cars parked in the garage for weeks at a time w/o using them (heated garage) and when i do use the car it takes several miles to get the 'bump' out
happens w/ the oem contis and now w/ dws contis as well as the good years on another car.

Yeah, I forgot to say - I have Bridgestone Potenzas (RE970 AS Pole Positions) which are basically the same thing as the Conti DWS. I read that because they are performance tires and have more nylon in them that the Potenzas tend to flat spot more but I don't know if this is true.

Like i said, this only became noticeable recently when it started to get really cold. It could have been happening before but at a very mild level and I just thought it was the crappy Jersey roads lol

[cobie56]

Originally Posted by Bliky

I'm like 90% sure it goes away after the tires are warm, assuming it's the tires. Unfortunately, it's hard to tell on almost all Jersey roads since they are bumpy to begin with -.-



Would the fact that the car mostly sits on an incline in my driveway? Nothing too steep but it's a bit of an incline make it worse? Also, the fact that it got worse when I installed the shocks make sense.

When I checked the pressure the other day they were all between 32 and 35 PSI. I'll make sure tomorrow they're all at 37.



Yeah, I forgot to say - I have Bridgestone Potenzas (RE970 AS Pole Positions) which are basically the same thing as the Conti DWS. I read that because they are performance tires and have more nylon in them that the Potenzas tend to flat spot more but I don't know if this is true.

Like i said, this only became noticeable recently when it started to get really cold. It could have been happening before but at a very mild level and I just thought it was the crappy Jersey roads lol

i find the DWSs flat spot much more that the oem contis

[FordCustomerService]

Originally Posted by Bliky

So, very recently my car has developed a problem than I just don't know how to get rid of. As a preface I did just install rear Koni Shocks and Steeda springs but this problem was happening before all of that went on.

Basically, if my car has sat for a little and I go to drive off the road feels REALLY bumpy... Almost as if i'm driving over a bumpy dirt road. The weird thing is that it goes away after I drive for a while but if you really try and feel for it, its still there. It's almost as if it practically goes away after part of the car is warmed up but not fully... At highway speeds it's pretty much not noticeable but if the cars been sitting and I do some city driving the car feels like its bouncing around like crazy.

The tires are new and after my suspension mods I had it aligned and all 4 tires balanced. They all have proper air pressure in them and I even pulled my spark plugs to check them... I have no idea what this is >.<

My Dad and a friend of mine seem to think it might be the DCT since it isn't warmed up all the way until I start driving around and this problem did start showing itself when it started getting REALLY cold here in Jersey.

I've even left the car running for 10 minutes before driving it and it makes no difference at all. So weird.

Hey Bliky,

It wouldn't hurt to swing by your dealership so they can experience what you've described. They'll be in the best position to get you some accurate answers and to advise on next steps. Keep us posted and let us know how things progress.

Crystal

[Bliky]

Originally Posted by FordCustomerService

Hey Bliky,

It wouldn't hurt to swing by your dealership so they can experience what you've described. They'll be in the best position to get you some accurate answers and to advise on next steps. Keep us posted and let us know how things progress.

Crystal

A visit to the dealer is lower on the list simply because I'm afraid it was some type of modification I made that caused the problem but it did appear to happen before I did my suspension stuff. The dealership route is coming quite soon. Thanks!

In other news... IT'S STILL HAPPENING. I filled my tired up to 37 PSI all around the other day and this still happens. It's still just as bad as before. It's really bumpy at any speed below about 35 and at highway speeds (65 MPH) about every 5 seconds you can feel a slight bump like I'm going over a crack in the road but it's clearly not the road since it does it for my whole 30 minute highway drive.

I'm wondering if I maybe bent a wheel but didn't break the bead of the tire? About a month or so ago I was driving home late at night and getting off an exit I usually don't get off and must have hit a bump in the road and it felt and sounded like it destroyed the whole front of the car. Even my friend in the car was like "holy crap". Nothing appears to be leaking (if it is it's VERY slow) and nothing looked bent.

[BetaDnB]

Something your last post reminds me of...make sure the beads are actually seated properly all the way around. They can still hold air even if they're not. When I was working in tires I had a customer with a Mustang with a similar problem. We rebalanced and made sure the wheels weren't bent. I drove with the customer in the car. He allowed me to get on it. I took a corner at a pretty good clip and there was a ridiculously loud POP. The problem was gone immediately. We came to the conclusion that part of the bead wasn't properly seated.

[Turb0x3r]

Sounds like tires. I remember when I had my STi with hard compound summer tires and when the temps got colder in Minnesota it made that bumping feel.