2007 Pontiac Solstice - car jerks when brakes are applied


#1

I have a 07 Solstice - automatic. Since I have had my car for 9 years, I do regular preventive maintenance & I let it warm up in the morning before I drive it.

In the last 2 weeks, when I apply the brakes, it jerks & it sounds as if the motor is about to fall out - this does not happen all the time, so far, it has happened on 3 separate occasions.

I took it to the shop & was told they hooked it up to the “big expensive machine” & there were no codes, nothing wrong so they had the alignment guys look at it & said that when I had the rotors & brake pads replaced last month, they were not burnished so they burnished them.

2 days later, it happened again, I drove it to the shop & my Service Advisor test drove it w/me for about 20 minutes & of course, the car did not jerk. He told me to keep track of what I did right before it started to jerk.

A week later, it did it again so I pulled over, turned the engine off, sat there for about 5 minutes, turned the engine on & it was fine, no jerking, no noise, ran perfect.

The 1st time it jerked, I simply pulled out of my garage & the other 2 times was right after I filled it up w/gasoline - so far it has only done this in the morning.

Any clue as to why this is happening & how to fix it? My Service Advisor is at a loss - please help!


#2

I think you may have a problem with your transmission, your lock up torque converter may not be releasing as it should. If you aren’t getting any codes, that may mean that the solenoid that controls the valve is working but that the valve is stuck.

Have you had the ATF changed? If not, at least look at it, if it is not bright ref, then get it changed. The fresh detergents should free up the valve. If you have this done, use a reputable shop, not a fast oil change place. The must do the following in order.
Drop the pan and drain the fluid.
Clean or replace the filter and the bottom of the pan.
Replace the pan and fill with fresh recommended ATF, in your case Dexron VI. Do not allow a universal fluid to be used, even with "additives that make it Dexron VI"
Optional, hook up a fluid exchange machine to remove the rest of the old fluid and replace it with fresh Dexron VI. This must be done AFTER the above. Many shops only want to hook up the machine and not do the other stuff, but that is not good for the transmission.

Talk with your dealer and see what they have to offer. They have the advantage that if you opt for the fluid exchange, their machine has likely only had Dexron VI in it and has not been contaminated by other ATF’s. They may be a little more expensive, but it could be money well spent. But they must drop the pan and clean the filter first.


#3

I will talk to my Service Advisor - thank you!


#4

I agree with @keith, could be the transmission. Also may be the brakes.

Question… Does the brake pedal kick you back and the car doesn’t slow very well when this happens? And is there a little round yellow light with “ABS” (under the speedometer) on at the same time? Does it stay on? Or go right off?

Pedal kick and a little noise would be the normal anti-lock brake activity IF the tires were about to skid. If the ABS light comes on, that indicates a problem. It can also happen when the ABS wheel speed sensors are going bad and sending a noisey signal to the ABS controller. If it solves itself (a failing but not failed wheelspeed sensor) and goes back off, there may not be any codes for the mechanic to read. He may have to take a road test or you take him out with his portable “little expensive machine” so he can read the sensors as you drive and hopefully capture the problem.


#5

The brake pedal does not kick me back & it slows down without a problem. The ABS light does not come on & the dash is pretty small so I am leaning towards no lights come on when the jerking is happening.

The 3 times it has happened, I have been either been pulling out of my drive way or out of the gas station, maybe doing around 5 mph but as soon as I press the brake pedal, it jerks & makes a horrible noise like the motor is about to fall out.

It does not have a problem gaining speed, it does not struggle, choke or feel sluggish until I press on the brake pedal then it sounds like all hell is breaking loose.

The 2nd time it happened, I drove it immediately to the shop for my Service Advisor to test drive but wouldn’t you know it, as soon as he got behind the wheel, it did not jerk, it drove perfect.


#6

Do you mean the engine seems to be cutting in and out…or losing power in some way? Doesnt seem to be describing brake rotors since you said it occured pulling out of your driveway. We love engine codes…so if you have a CEL illuminated…we want the codes. If no engine light…it changes the troubleshooting method a bit, but still… the problem can be sussed out usually.

This can surely be many things. Even tho this is an odd thing to suggest, it can be as simple as the battery arcing out under the hood ! When a battery is not secured properly they can shift round and find something to ground out upon. When this happens…all sorts of chaos can ensue…BAD things too…such as a vehicle fire. Very easy to check…just see if the battery is secure under the hood and that the cables are nice and clean and tight. Measure the voltage at the battery with engine running too.

I will never forget trying to diagnose a vehicle with similar attributes…and it wound up being the .50 cent battery hold down block…that was not there! It surely was NOT on my list of suspects or even in my thoughts at the time…but I can tell you this…it has remained on my suspect list ever since and I have found many many similar situations.

Ive also found alternators producing too many Volts DC when the internal voltage regulator fails and it makes the alternator throw out too many volts, overwhelming the computers on board…and basically everything else to boot. In fact I just repaired a pristine Caddilac Allante with this exact issue…The alternator was brand new so no one looked at it twice. Many attempts by shops to repair all the strange symptoms…but a simple voltage test while running revealed 29-35 VDC output from the alternator. I told the owner its his alternator and he firmly denied…I had to show him. Repaired the car in under 5 minutes. He was dumbfounded. Quality control is real people… LOL

Anyway…these suggestions are just food for thought…this issue could have many causes, so we hope to see some codes in the future.

Blackbird


#7

When I press the brake pedal, the engine sounds like it is going to die/cut out but it does not; as soon as I take my foot off the brake pedal, it is fine & gains momentum.

I had the starter & the battery installed last month by the shop [dealership]; I will look for my receipt & see the time lapse between the new battery installed & when this problem started, maybe there is a connection.

This is the first time I have had to deal w/car issues, car shops & service advisors, my ex-husband always took care of it so I am at a loss when it comes to the lingo & car problems but I have to learn even if it is the hard way.

I truly appreciate all y’alls suggestions.


#8

It could be as simple as the Power Brake booster …which would then point to vacume leaks. This is one of those things that you need to be onsite for when suggesting possible suspects.

When you step on the brake pedal…you are activating the power brake booster which is operated by engine vacume. If there is an extant vacume leak issue prior to the brake adding to it…you could see similar symptoms. Very difficult to diagnose from here. Especially when there may be some telltale sounds to listen to while onsite.

Sounds like an interesting issue. But…the thing that links the brake pedal to how an engine runs…or does not run… IS Vacume.

Blackbird


#9

As soon as I am told what the problem is & the solution, I will definitely post it.


#10

Thanks for the updates @Solis. So many people post here asking for solutions but we rarely find out if we helped or not.


#11

Has anybody checked the motor mounts?


#12

Motor mounts have not been checked.


#13

Since this problem seems to have first occurred soon after replacing pads and rotors, my first suspicion is that the rotors were not properly cleaned before they were installed on the car. Rotors rust like crazy sitting on the shelf waiting to be sold, so part of the manufacturing process is to coat them with some gunk like substance to prevent rusting. All of that has to be removed before installing the rotor or it will cause braking problems like this. Experienced shops usually have a big tub with hot water available where they wash the rotors with soap and water and maybe some solvents to thoroughly clean the rotors.

If they forgot to do that, now this gunk is not only coating the rotors, but also the pads. Cleaning the rotors should be possible, but it may not be a simple thing to clean the pads now they’ve been mashed into the rotors. If this is indeed the problem, the best solution is probably to remove and wash the rotors as should have been done in the first place, and replace the pads.


#14

The OP stated that the braking and subsequent engine cutting out was occurring in the driveway…so your above issues that could be present arent yet exemplified when the car is at a walking pace in driveway speed maneuvering.

Initially I was headed in the same direction…but redirected when I saw that there was no high speed braking involved to expose rotor warp or contamination problems. At least that’s how I read it?

I just got back from the shop and while victorious…Im exhausted. Roger-Doger…Over n OUT

Blackbird


#15

I’ve never driven a car with that problem @“Honda Blackbird” so if you have I’ll bow to your greater experience. But in the absence of actual evidence, I’d guess that grabby brakes might be even more grabby during slow speed braking compared to high speed braking. The reason being a bigger difference w/grabby brakes in the coefficient of friction, static vs dynamic.


#16

When the jerking happens, I have always been traveling at a slow speed. It has never happened while traveling on the freeway/high speed.

When I stated it happened as I was pulling out of my garage, I meant, I pulled out of my garage just fine, drove to the end of my street, stepped on the brake pedal & it jerked. Sorry for the confusion.


#17

It sounds as if the engine is trying to die on you when stopping. I like the tranny fluid replacement idea. I would also have the throttle body cleaned and the Idle Air Control valve cleaned. If you are letting off the gas, the IAC is supposed to keep the idle from dropping to low. A dirty throttle body will also affect idle.


#18

My car has not jerked in a week but it is going in the shop tomorrow. I am hoping they figure out what is wrong w/it.

I am going to give my Service Advisor a print out of all the suggestions listed here. I will keep y’all posted.

Thank y’all for all the suggestions - they are very much appreciated!


#19

The shop idea is a good choice. Let us know the result OP.


#20

My car has been in the shop 2 days & they still have no clue as to why it is occasionally jerking - still no codes.

I read some where else that maybe the intake camshaft position actuator solenoid valve might be getting stuck open but my Service Advisor said that cannot be it. shrugs