LOUD knocking underneath my car; scared to drive it?

Question

(Sidebar: I drive a 1996 Camaro, 3.8 v6)
To make a long story short, I was involved in a 55mph side impact back in October of 2006, on the passenger side. I had to deal with some shady bodyshop chosen by my parents (and because the insurance company claimed they were very dependable). As soon as I got my car back, I kept noticing this loud rattling sound from under the passenger seat, under the car. I figured it was the catilic converter and had the owner of the body shop look at it. Another long story short, insurance company refused to fix it because "there's no way to tell that it was accident-related". Funny how it never started
until AFTER the wreck though, huh? Anyway, today I got in my car (it's a 5-speed) and as I back up I heard a loud "knock" from under my car. I started driving and the knocking became so loud and was hitting from under the car SO HARD, that it made my stick shift move and I could even feel the vibrations under me. What could this be? Help!

I only drove it a very short distance in the parking lot and noticed every time I heard the "knock" it felt like I was running over something. Like a rhythmic bump, so to speak. I looked under the car and nothing is hanging down, but a Camaro is so low to the ground anyway, I guess it'd be hard to see if anything were out of place. I appreciate ALL your help! I haven't delt with the body shop since January and don't intend to. Can anyone recommend a shop in the Lewisville/Clemmons, NC area? Thanks!

Answer 1

i own a repair shop,and it sounds like it may have dropped a drive shaft out of it or something,its possible this got damaged when it got hit,especially and it being from the side of it,you need to have someone look at it,it either has a bad drive shaft or has lost a universal joint in it,what ever it is its a rotating sound ,and anything that turns on it under neath of it can cause this,and there's not that much that turns at that point,so id say it is related to the accident,but proving this,is a very hard thing to do,about all you can do with it now is repair it,and drive it,shops today are more interested in the money than the work,one thing they need to remember,you cant have one without the other,good luck with it,i hope this helps.

Answer 2

You have an engine or transmission mount broken under your car. Perhaps the cross member is loose that runs from side to side under the back of the transmission. Like you say, camaros are so low to the ground the only way your going to tell is to get the car on a lift and have a good look. If you got hit in the side at 55 mph in a camaro you are one lucky gal to still be with those of us in ya-hell. Good luck.

Answer 3

I would have to say my first thought would be the drive shaft, a U-Joint or something else along the drive shaft. I know you really gave alot of detail about what is happening and whats its like, and thats helpful, but seeing as none of us are there uner your vehicle or in it when the noise is being made, no one can give you a definate answer.

Listen to Dodge man, I've seen his answers, he really knows what hes talking about, so you can take what he says as a true and honest answer.

Here is some help on the repairing side of it. You need to stop having your parents deal with the shop and start chosing it for yourself, if you are old enough that you parents will allow you to do this. if not sit down and discuss it with your parents. here is some advice.

1) You want and ASE certification, trust me, these tests for your ASE certification are not easy or cheap. If someone has this and has it displayed, its a good bet they know what they arre talking about. unfortunately, thats not always enough.

2) You will want to visit the web-site for the Better Business Bureau. This is a national bureau that investigates complaints against companies and keeps documentation on who has unresolved complaints against them. You can also use their site to locate shops in your area who are members of the Better Business Bureau.

3) Once you have found a shop, call them, explain to them what the issue is, they wont be able to tell you whats wrong over the phone, because they wont know, but it will give them a good idea of what to look for when they get it. If it is reletively close, drive it, if you are truely scared to drive, have it towed in. Most shops will charge a fee of about $50 to diagnoss a problem, this fee is typically waived if you have the work done there.

4) Explain to the shop that you have been in an accident and ask them if they believe that that may have caused this, and if so, if they have anything that can provide, such as a written statement saying that the damage was inflicted by the accident.

5) If you have the repair done and they can provide you with a statement verifying that the damage was a result of the accidnet, calll your insurance company. Tell them you have an ASE certified mechanic who can verify what would have caused the damage, and send them a copy of the statement, the ASE certification of the Mechanic(s) that worked on your vehicle, and verification they are a reputable shop (show they are a member of the BBB site)

I hope this helps, and good luck

http://www.bbb.org

Answer 4

Your car has a serious problem that needs to be looked at by a qualified mechanic. Do not drive at highway speeds until this is checked out. Your safety is at stake. Stay away from the shady body shop and look for a repair shop that shows it's ASE qualified. That will help insure a good inspection. Good luck.

Answer 5

One thing no one has mentioned. There is a bar running from the rear axle to the transmission. On the trans end it is clamped to the tranny with a rubber sandwich. If it is not in its rubber mount, the bar will lift up and hit the floor behind the shifter on accel and pull downward on braking or decel.

Answer 6

Sounds like possibly a broken transmission mount or could be as simple as the exhaust hitting the floor.

Answer 7

judging by the responses, i think its some guy who has a crush on you who is hiding under the car. its his head hitting the underside. u must have incredible magnetism. i have to ask, what did the body shop guy say? could be a bouncing exhaust system.

Answer 8

don know
did u try pulling out the 70 yr old granny from under the car..the one u ran over miles back.

Answer 9

First of all.. all you guys that answer as jerks, your the reason women cant get any good help with there cars.
Dodge Man has the right idea, I would take his advice.

Answer 10

sounds like the exhaust is hitting on the floor board.or a broken tranny mount.