Car shakes at 2000 rpm

Hey there. Im new to the site and joined to help get info on my friends car she is having trouble with. She has a 2007 aveo and it has about 60,000 miles.

Check engine light comes on and off and the codes read...the cat converter, cat seals, cam shaft, and high idle. The car also shakes when accelerating and hitting around 2000 rpm.

She just replaced all four tires and did an alignment. We have been to three different mechs. When getting the tires and brakes check one noticed a loose ball joint and could turn the nut (or part used to held, again dont know this car) with his fingers.

The mechs are saying ignore the codes but obviosuly something is wrong. I didnt know if a bad c/v shaft, wheel bearings or a busted axle could cause the shake. I know she needs brakes but not sure how to tell if they are warped. Also could anything in the trans me causing the shake.

Im sorry if I dont know all the terms, I am still learning. I hope you can help. Thanks!

sounds like a few different issues.

test the brakes by lightly pressing the pedal, just enough to feel feedback but not really enough to stop. does the pedal pulse?
then push a little harder, and a little harder in different attempts, how does the pedal and car react?

the ball joint you might feel especially if you cn turn it by hand.


what kind of shaking is it? the steering wheel while driving? the whole car? does it happen at stop signs, lights? etc?

at 60k miles has she done the timing belt? it might be out of time? it is due for a replacement.

I know the timing belt needs to be replaced. Supposedly its been replaced before because the mech found a piece of the old one somewhere. Her car is just a ball of questions, there are no service records so a tune up is much needed. I believe its a lemon, we learned it was in a front end collision and that the PCM has been hit so im not sure if that can mess with sensors.

The whole car shakes and ive only notice it when she accelerates and it around 2rpm and then sometimes when coming to a complete stop. Her brakes squeak so i know that can influence.

Its just trying to figure out if the check engine light on has to do with the shaken but it seems like all seperate issues.

I will see her tomorow so will do a drive in her car and do what you said for the brakes. She hates spending money but part of owning a car is keeping it up. So I told her to get another alignment, new brakes, change all fluids, new sparks wouldnt hurt too since she has no record of maintence on it.

If its reading off cat code should it be replaced?

Sorry so many questions, im so used to my vehicles and this is just out of my ball park and no mechs will take me seriously since im a girl. I told pepboys to check her brakes and evidentally they didnt because they would of caught that ball joint that the other mech found. So i appreciate you taking the time to try and help.

Have the motor mounts been checked? One of them could have been ruined in a collision, They aren't great to start with.

A proper mechanic should never tell you to ignore the codes. Have a professional check the exhaust for leaks or a clogged catalytic converter. O2 sensor may not be working correctly is another possibility. There is A lot that could be wrong, especially with multiple issues, Take it slow diagnose one thing at a time, you should be able to get it going good for her without spending too much money.

Thank you so much for your help! Im writting all this done and will just check one thing at a time. Greatly appreciated :)

well with the accident issue, you should definitely look over the car for anything that could be the issue.

is this an issue that just developed suddenly? or has slowly gotten worse over time? was there any sign of it when she bought it?

if the engine runs, the ecu is most likely ok. its a printed circuit board. if it was cracked/accident damaged, more than one sensor would be off.

the codes are what you need though if this is a running issue. IF this is an out of balance issue (shaking) then it is accident related.

She purchased the car from her father in Jan i believe and just learned of the accident two weeks ago. Yeah messed up her own dad, and the car came from a shady dealer in Alabama and is not shut down. No car fax, records or anything. Only proof of accident i see is the shotty bondo work on front right fender and the mechs "word" about the hit PCM, said the wires were like siliconed on there. Would I be able to look and see for myself, is it easily seen?

This past month is when its gotten worse, i believe she said its shook since she has owned it. I know her father did tell her bondo was in the oil pan, how it got there no clue!

The codes reading off are:
P03040
P0420

When i see her later today ill get the paper i believe there are 2-3 more.

She only paid 6 for the car, owes 4 so if costs gets too much its kinda not worth it, she loves the aveo but this one in particular is just a ball of questions.

the computer is right beside the battery, with the harness plugs right there. look at the body seams in the engine compartment too to try to figure out how hard it was hit. take a tape measure and X out the fender bolts to see if it is square. (furthest back on one side to front on other side, take measure, then switch and measure and compare.. within 3mm is tolerance.

Thanks I will do that! My husband trained me on the basics but us being military wives got to diagnose and stuff on our own sometimes so thanks a lot!

well if you need any more guidance, just ask. taking pictures of questionable things and posting them here helps for comparisons too.