Aggressively pulling to the left on acceleration
 

I have noticed the last month my car is pulling HARD to the left when i hit the throttle. When i release it it snaps back to the right and drives perfectly straight with hands off the wheel. Its getting to feel very unstable on the highway. You cant really feel it until 40-70mph or higher. There is 30k miles on the car now (2014 FRS). I took it into the dealer yesterday because my battery would no longer hold a charge and asked them to check it out. They took it for a 1km test drive (not sure how you could leave the dealer and replicate the issue and come back in 1km), then they put it on a ramp to check for bent parts which was pointless because i know the car has never been driven hard, drifted, raced hit anything or any other abuse. After all that they gave me a $70 bill and said the tire was a couple PSI low on one side and "it seems to drive straight". I have had other people drive the car and say it does not feel right. Anyone have any ideas what it could be. I was thinking it could be something in the LSD? Any ideas would be great before i go back to the to the dealer.
Thanks

alignment, blown shock, bad toe rod, axle, unbalanced wheel/tire.

Gremlins

They put it on a ramp to check for bent parts?

Where is this shop? Mexico?

Sounds kinda hokey


You need an alignment. Sounds like your rear toe could be out. (My best guess)

busted linkage or, like these guys, rear subframe.
[ame]http://youtu.be/5YvuHbf0cIk[/ame]

Had a similar issue in a friends. But the tire was a good 15 psi low. Not a couple. May want to double check your tire pressures. Particularly the rears.

Hopefully that's the case and not something more serious.

Are you on stock wheels and tires?

I'm on steel rims and winter tires for the winter. I would expect the alingment would be more logical to check than bent parts. I dread going to the dealer again. The car tracks perfectly straight when your coasting. I figured that would rule out alignment?

This is a misalignment that is induced by longitudinal force applied to the rear axle carrier. Something is broken and allowing it to flop around.

This is a hazardous condition and the vehicle should not be driven. If you are not comfortable with diagnosing and repairing it yourself, have it trailered to a shop.

Do a wheel balance and an alignment check.

alright thanks for the replies. Im going to bring her in for an alignment check, and balance ASAP to see if that fixes her. Il have a good look when i have her on the ramp and see what i can find! I update the final cause/solution. Thanks

I am going to put money on this.

make sure to check for blown-out bushings.

happened to me, turned out one of my rear tires were low on air. filled it up, was good to go!

Alright so I promised I would update so here it is:
Since I started this thread I have been to 3 more garages. I have changed out my rims and tires. My aingment was 100%. Every garage told me to stop driving it because it is unsafe so this is getting pretty old by now. I've spent over $500 to try and get it solved and no one knows what's happening. I am going to get the car back to Toyota and hopefully this time they will figure it out. In case anyone else is experiencing this problem, I will again post if I get any closer to a diagnosis. It's bad enough that on a icy highway the car has been thrown sideways at 70km/h twice under only light acceleration.

If dealer can't diagnose the issue, try finding a shop specialized in suspension/alignment work for race cars.

Here's something out of the box.

We know our cars have accelerometers and speed sensors at all 4 wheels, blah blah...

What if it's a malfunction of the VSC? Try doing the pedal dance to completely defeat all that stuff.

Idea
 

I had a truly bizarre thing very similar to this on my Integra TypeR a number of years ago, and it was stupefying to everyone. Nothing made sense. We looked at suspension components, tires, alignment, balance, etc. And it was SCARY at speeds over 40MPH.

FINALLY a service guy at Acura decided to test a theory that something was wrong with 1 wheel (tires had been changed - no fix). He swapped left and right drive wheels (even though they were directional, this was fine for the test).

When he did, the "pull" changed direction. Then he knew it was the wheel. Took it to a shop - they straightened it, and the car was a back to normal after that!

Turned out (if I remember correctly), that there was a side-to-side wobble in 1 wheel (it was bent) that looked "in balance" to the machines, but caused this strange pull.

You might try swapping left and right rear wheels (leave tires on them) just for a test.

Steve

Okay thanks for the replies. I shall let them know a few things to try. The service manager said he found this forum and read this thread.I had the car roadsided to Drayton valley Toyota. They have been good so far. Toyota is offering $40 a day to cover a rental car and someone from corporate said they will have some team aid the dealer with the diagnostics if need be.

Did you ever identify the cause?
My 2013 BRZ has done the same thing since the day I got it.
I can change lanes to the left with the gas pedal. The steering wheel does not move and it feels like the problem is coming from the rear suspension.
Sub Svc says there is nothing wrong and is no help at all.

WTF tested 1km? Did they at least have radio on and high beams on? Gotta put a little strain on battery to check it imo.

I had pull to left on my 2014 too. I mentioned it to my dealer and they also said one tire was low psi but i didnt get charged! I later swapped to TRD springs and its gone?

so, give the springs a look!~

I'm curious as well what was the fix?

may be your weight... just trolling haha

Why didn't the sensor catch this. It would have to be so low its noticeable when you look at it

I don't think the OP is responding.... this post is from Jan of 2015.

Well their last post was in November so there is hope they may show up at some point.

How are your motor mounts? i know it seems kinda funky but my motor mounts are worn and it feels as if the engine shifts upon acceleration and pulls in the direction that the motor shifts to. Just food for thought

what happened!

What happened to what? Who are you asking? The OP has been gone for 2 years.


Did you actually mean to post here: http://www.ft86club.com/forums/showthread.php?t=89274

My car (2014 Scion FRS) is doing this as well. Going in for alignment Monday, already balanced wheels last Friday. I know this is an old thread, but going to try and figure it out on the behalf of everyone else. I don't remember the car doing this when I got it, but after I did the 60,000mi service is when I noticed it.

I do have the carmax max care warranty so hopefully I can resolve the problem with my $200 deductible and figure it out for all of us.

Sounds like the OP is driving the FWD version of the Triplet..

Nope.

With a wonky frontend, the car will go mostly straight but the wheel will be crooked, with a wonky rear axle, even if the wheel is straight the car will try to rotate to wherever the rear is pointing.

Even in a fwd, a loose rear end is way more unstable than a loose front.

Update. Swapped left rear tire with right rear tire, car pulls in opposite direction now. (To the right). Will be skipping alignment until I get new tires.

That'll happen soon. Right?

and you'll be getting 4 new tires?

i'm learning very quickly with all these posts that this car does not respond well to cheap maintenance procedures like doing 1 or 2 tires at a time.

@soundman98 I got by alright on stock tires just changing 2 at a time. Now on sticky tires though, probably wouldn't work out so well.

Just got 4 brand new firestone indy 500s BRAND NEW CAR! OMG These are sticky. No more pulling to left or right on acceleration. I can no longer slide the rear end out either, it just wants to stick and go go go!

Firestone did break one of my wheel studs so I had to limp home then replace it, but a quick youtube video and an hour later, back on the road. If you want some great performance for about $100/tire Get the Indy 500's you won't be sorry.

New tires put on last night. Solved problem.

So recently I had a left rear tire separate halfway through a 4.5 hour drive home from the cottage. Had to put the spare on the drive axle, and drive 2.5 hours home like that with the car pulling like a bucking bronco every time I touched the throttle.

So I can chime in with certainty that this issue most likely has something to do with the rear axle set up in most cases, whether it be unevenly worn tires or a bad alignment. With the spare on one side, and a 9.5-inch-wide wheel on the other side, it was doing this like CRAZY.

4 new tires and an alignment and she drives laser-straight now.

Was this ever resolved? Having exact same problem, tire pressure and alignment are good