Horrible understeer and body roll on my E46 BMW 330

[ZSP-Mafia]

Lets see if I can explain this problem coherently. About 2 weeks ago, I had my rear tires replaced with identical Pirelli P-zero's. When I left the shop I could immediately tell something was "off" with the handling, but I figured maybe the new tires needed a few miles to break in. I made it about 2 miles on the freeway and noticed that the steering felt a bit too quick. It felt like both wheel's had a huge amount of toe-out and it was difficult to even drive a straight line. So I decided to turn around and go back to the tire shop. I took the next 40mph off-ramp at no more than 40-50 mph and felt the wheels turn but the body just rolled into the corner and plowed towards the outside. The DSC lights lit up as thankfully the car basically slammed on the brakes to keep me from understeering right into the wall. I was pretty pissed at this point as before I visited the tire shop, the car handled just fine. I went in there and explained what I experienced and the guy thought I was crazy and insisted they hadn't touched anything but the rear tires. We looked the car over real well and they noticed that the rear tires were a bit overinflated, so they took some air out, went for a drive and everything seemed to be fine. a couple days later the problem was back and stayed pretty consistent. I tried messing with air pressure etc, to no avail. I had ordered some strut tower reinforcement plates previously and just installed them last night, and while I was down there I figured I'd try tweaking the tie-rods a bit and toe-in a bit more. Sure enough... Voila!! the car handled like new, tracked staright,no body roll, just great! Good news right? well... no :( I decided to celebrate my new, awesome handling car by going for a spirited drive and sure enough, about half way through, it started again. The whole car feels like its on leaf springs and any attempt to Go around a corner quickly is met with the car plowing to the outside and the DSC slamming on the brakes. Ok, now here's the really strange part... I immediately figured something was wrong with my tie rods and they just couldn't hold an alignment but then, I'm on the freeway for 15 minutes and the car is cured again, no body roll no pulling right or left, just perfect. :eyecrazy :mad

Right now Im leaning towards something being wrong with either the power steering or the adaptive steering. Anyone else have any insight?



Cliffs: Car handles like poop...randomly.

Car currently has 100,000 miles, with new control arms, CAB's and endlinks.

[danewilson77]

When was the suspension last replaced?

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[ZSP-Mafia]

Everything except springs and tie-rods has less than 10,000 miles.

[billschusteriv]

When was your last alignment and did a BMW dealer do it?

[ZSP-Mafia]

When was your last alignment and did a BMW dealer do it?

I have the car aligned every 4000 miles or so. It's not done at the dealership. I really don't think it's an alignment issue though, as it goes back and forth. I'm leaning towards a sway bar issue right now.

[danewilson77]

Bad endlinks perhaps?

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[ZSP-Mafia]

I don't think it's the endlinks. There's no clunking or tearing. I'm suspecting it may have something to do with the sway bar bushings. I'll have it up on the lift tomorrow and let you know what I find.

[danewilson77]

Sounds good bro. I hope you find something definitive. I hate throwing darts.

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[ZSP-Mafia]

Sounds good bro. I hope you find something deinitive. I hate throwing darts.

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It just makes it so much more difficult when the problem isn't consistent. Grrrrrrrr!!

[billschusteriv]

Sounds good bro. I hope you find something deinitive. I hate throwing darts.

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It just makes it so much more difficult when the problem isn't consistent. Grrrrrrrr!!

I know what you mean. Good luck.

[jvr826]

How many miles on the car? It's 10 years old, original wheel bearings? Your front suspension components may be all new, is the rear as well? RTABs and other bushings? Push up front could be the result of something off in the rear too.

How much tread left on those front tires?

I'll share a story from a friend with an M3 with staggered wheel/tire setup. He replaced just the rears and had odd traction control behavior, even though the fronts had plenty of tread. True the tires were different brands/models, but I think the lesson learned was, any traction differences could effect "handling." He ended up getting new fronts of the same make/model as the new rears and the problem was resolved.

I run a square setup, but even when I didn't, I always replaced all four tires at the same time, even if I was using the same make/model tire.

Looking forward to hearing what you find out today.

[ZSP-Mafia]

^ Car is just now hitting 100,000. I replaced the RTAB's and diff bushings less than 10,000 miles ago. I do need to get new shocks for the rear but I dont think thats the cause. One of the main things I suspected was the new rubber in the back, especially since that appears to be when the problem started. But the fact that the problem occurs even when I'm travelling in a straight line, (at least trying to) and also comes and goes seemingly at random, has me baffled.

[ZSP-Mafia]

Hmmmm. I wonder if it could be a bad steering angle sensor.

[ZSP-Mafia]

I give up. I'm goin to see Shane on Thursday.

[Marcus-SanDiego]

I give up. I'm goin to see Shane on Thursday.

Ftw! I will meet you over there. What time?

[ZSP-Mafia]

Ftw! I will meet you over there. What time?

Can you find out for me what time would be best for Shane? Anytime on Thursday works for me.

[Marcus-SanDiego]

You'll need to call Tom -- his brother. It really depends on how full their schedule is.

Tell Tom that I'm referring you. You're a member of the ZHP Mafia.

[ZSP-Mafia]

11am tomorrow.

[Marcus-SanDiego]

Cool. I will cruise over there.

[mikeyb74]

So...What was the problem?

[danewilson77]

So...What was the problem?

I think it's going down today at 1100.

[Marcus-SanDiego]

So...What was the problem?

We will find out today. Shane, the owner of Euro Auto Spot (in San Diego), will be looking at this personally. I'm curious to see what it is.

[Hornung418]

We will find out today. Shane, the owner of Euro Auto Spot (in San Diego), will be looking at this personally. I'm curious to see what it is.
Thank God. I've been hoping this would get looked at professionally. After all the troubleshooting we did, I was beginning to think the car has demons.


DROIDstatus. Come at me, bro.

[ZSP-Mafia]

At first glance, it appears the springs are installed incorrectly. Hopefully it's something simple like that.

[danewilson77]

At first glance, it appears the springs are installed incorrectly. Hopefully it's something simple like that.

OMG!

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[ZSP-Mafia]

Springs reinstalled correctly, USM's were completely demolished. Basically, none of the front suspension components was functioning properly due to the springs being installed wrong. So far, car handles great, needs an alignment but I believe my drama is solved.

[Marcus-SanDiego]

Good news, James. Glad Shane could get it squared away.

[ZSP-Mafia]

He is the master. :)

[Marcus-SanDiego]

That's what I tell everyone. :biggrin

[danewilson77]

HOW IN GODS NAME, AND ON HIS GREEN EARTH, DO YOU INSTALL A SPRING INCORRECTLY?

Were the springs not seated on the perches properly? Did they put the fronts on the rear, and vice versa? Did they install them upside down?

And...more importantly.......didn't you take this in to have tires put on? Did they not re-seat the springs? Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh hhhhhhhhhhhhhhhh!

I must know.

***Apologize in advance. I get emotional about suspensions.

[ZSP-Mafia]

^I'll go into more detail when I get home.

[danewilson77]

^I'll go into more detail when I get home.

OK...thanks bro.

[ZSP-Mafia]

So anyway... It turns out that H&R springs sit differently on the perch than other springs. I had the end of the spring spun all the way so that the very bottom end was resting in the little groove in the perch, but apparently thats wrong. The H&R's are oval shaped near the bottom and that is supposed to match up with the perch. So I was about 90 degrees off on both sides. Handling is drastically improved but the steering still feels way too quick to me and Im still getting alot of understeering. Im going to get it realigned right now though, and hopefully that'll take care of it.

[Marcus-SanDiego]

Yeah. I remember Shane saying that there was some serious toe-in? He seemed convinced that an alignment would serve you well.

Let us know, jefe.

[danewilson77]

That toe will chew up your tires....quick like.

[ZSP-Mafia]

Problem not solved I'm afraid. :(

Steering is still entirely too sensitive and unpredictable at highway speeds.

[ZSP-Mafia]

Alignment settings...

http://i515.photobucket.com/albums/t355/jamesfogarty05/969d048c.jpg

[danewilson77]

Alignment settings...

http://i515.photobucket.com/albums/t355/jamesfogarty05/969d048c.jpg

I wonder if those are the same as mine I had posted. Gawd I hope so.

HTC Thunderbolt in da hizouse!

[ZSP-Mafia]

Something looks wrong?

[danewilson77]

My specs were in the "need some info" thread

http://i1015.photobucket.com/albums/af278/nicee46/tapatlak_1300480199363.jpg

http://i1015.photobucket.com/albums/af278/nicee46/tapatlak_1300480203921.jpg

HTC Thunderbolt in da hizouse!

[ZSP-Mafia]

Hmmmmm. I'll have to compare when I get home.

[ZSP-Mafia]

The only red flag I can see is that my caster angle is below spec. How is caster adjusted?

[danewilson77]

The only red flag I can see is that my caster angle is below spec. How is caster adjusted?

It isn't adjusteable...at all.

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

Weakness. I'm stumped. What should I throw money at next?

[danewilson77]

Regarding what? I thought it was fixed.

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

No, the steering is still vague and unpredictable. I've been searching and there are 19,000,000,000 threads with people having the same problem with no answers. GRRRRRRR!!


This guys story is identical to mine... No solution of course. http://m3forum.net/m3forum/showthread.php?t=333395

[danewilson77]

Steering guibo?

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

Brand new.

[danewilson77]

Front sway bar bushings?

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

Changed em in November

[Marcus-SanDiego]

Well, at least you eliminated one problem. The springs are correct now.

I hope you get it resolved completely.

[danewilson77]

FSM's, endlinks, tires, ????

Refresh my memory...pls.

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

FSM's replaced yesterday, endlinks, control arms and CAB's are all new. Only thing not replaced was tie-rods, but Shane checked em and they're fine.

[danewilson77]

Mmmm.....how many miles on tires?

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

Here's another guy with the same problem.

http://forum.e46fanatics.com/showthread.php?t=767252

I've been suspecting the steering rack as well, but have read threads where people replaced them with no results.

[ZSP-Mafia]

Mmmm.....how many miles on tires?

Droid Bionic! Boom! Winning!

Front tires are a bit worn but certainly not enough to cause what I'm experiencing.

[danewilson77]

Are they "a bit" worn on the inner edge? You had toe in issues....didn't you?

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

They are very slightly worn on the inside.

[danewilson77]

Are you running a staggered setup?

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

Yes

[danewilson77]

Damn...I was hoping you could swap front to back.

Droid Bionic! Boom! Winning!

[ZSP-Mafia]

Back to Shane we go. :)

[Marcus-SanDiego]

Let me know what day you go over there.

[prowlerflyer]

If it's any help, I've got half worn PZeros (staggered set-up) with a good suspension, alignment and I feel they are darty with any pavement imperfection. They have immediate turn in to a corner, sort of like a toe out alignment although the toe is w/in spec. Don't really know if this is a PZero characteristic or not, it's the first set I've had.

[ZSP-Mafia]

I'm pretty convinced now that the problem is not tire related. I know exactly what you mean about the Pirelli's though. I drove about 4 hours last night to LAX and of course it was miserable most of the time. But I could feel a distinct change in handling, seemingly at random, throughout the trip. One second I'd be fighting to keep it in a straight line, and the next, it would handle great. Very strange.

[ZSP-Mafia]

Goin to Shane's on Wednesday at 10am.

[Marcus-SanDiego]

I will possibly see you over there, JF.

[ZSP-Mafia]

Going to pick the car up from euroautospot. They said it was just a loose bolt on the end-link, which I'm extremely skeptical about. But we'll see, I guess.

[ZSP-Mafia]

Still not fixed... This is getting old.

[Hornung418]

James...this is depressing to hear :(

[Marcus-SanDiego]

Still not fixed... This is getting old.

Man. Have you taken Shane with you in the car? Sounds like a ride along is in order at this point.

[ZSP-Mafia]

Man. Have you taken Shane with you in the car? Sounds like a ride along is in order at this point.

I guess Shane wasn't at the shop when I took it in. Whoever looked at the car told me they couldn't duplicate any of the symptoms I described, which I find very hard to believe. I also asked them to investigate the "clunking" sound and feel coming from the steering column and they never got back to me.

[Marcus-SanDiego]

My suggestion is that you ride along. As you hear the noises, you can point them out.

[Hornung418]

When you experience the terrible understeer, is the car accelerating, same speed, or decelerating? If there's an issue with your drive line, it might be impacting the handling. Have you replaced the center mount and drive shaft flex disk?

[ZSP-Mafia]

When you experience the terrible understeer, is the car accelerating, same speed, or decelerating? If there's an issue with your drive line, it might be impacting the handling. Have you replaced the center mount and drive shaft flex disk?

The understeer issue is resolved. My only issue now is the vague/unpredictable steering feel. I showed Shane the problem with the clunk in the wheel, but whoever ended up working on the car insisted they couldn't find a problem, even though it's easy to duplicate even with the car sitting still. I'm gonna see if I can get Shane to look at it personally.

[ZSP-Mafia]

Inner tie-rods are shot. Got a mechanic to put it on a lift and listen while I turned the wheel, and voila! It makes sense... It's the only component of the front suspension that hasn't been replaced.

[Hornung418]

Glad you found the problem, Jim!

[ZSP-Mafia]

Glad you found the problem, Jim!

Thanks... I hope that's it.

[Marcus-SanDiego]

Inner tie-rods are shot. Got a mechanic to put it on a lift and listen while I turned the wheel, and voila! It makes sense... It's the only component of the front suspension that hasn't been replaced.

Excellent, amigo. Hopefully that solves it.

[Gordo_GT]

I will inspect my inner tie-rods as well. I had same/similar issue after getting my rear tires replaced. OEM staggered zhp setup with Michelin Pilot Sports. Also replaced LCAB's and had an alignment done. Issue seems to be more evident when I have a passenger. Tramlining is pretty bad and understeer is pretty exaggerated. I kinda get the rolling feel on the tires when turning (feels like being on a skateboard and kinda losing your balance and then recovering). It was pretty much like night and day. I remember going back to the alignment shop and getting my car re-aligned but issue persisted. My tire pressures were set to 32F and 36R by Costco, I don't remember what I had them like prior to the tire change but I know they were much higher. I will change my tire pressure to 36F and 38R tomorrow morning. I will take a trip from Sacramento to Sonoma and the next day from Sonoma to Mendocino (taking scenic route 1) and will post an update. Hopefully the different tire pressures get rid of the understeer and "rolling" feeling at least.

[ZSP-Mafia]

Tie-rods is a possibility. There are just so many components of the suspension that can go bad and troubleshooting can be such a nightmare.

[Gordo_GT]

Apparently Costco placed my tire pressure at 32F and 46R instead of 36R. I increased the front pressure to 36 and decreased the rear to 42. The issue is less evident now, takes turns at speed much better. I will adjust the tire pressure to 35F and 37R when I visit a gas station again. I expect the handling to be much better. I still can't believe I had a difference in tire pressure of 14psi, the staggered setup is only a few inches wider in the rear (255 opposed to 225).

[Gordo_GT]

I can report after taking a roundtrip of 500+ miles that the symptoms are gone. The similar issues as the OP were just due to the differing tire pressures (14psi difference between F and R). My car felt great in patches where there was new asphalt; perfectly straight driving and no vibrations/shaking of any sort. I will create a new thread with routes members should consider taking.

[danewilson77]

LOL...air pressure. I swear....