Need help diagnosing a new problem.

[Gatt9]

Car: 1998 firebird, suspension is stock except front sway bar is changed out for v8 sway bar. Alluminum driveshaft, full exhaust.

Problem: Loud banging sound from right rear tire area on initial acceleration from a stop, does not occur on very light acceleration, once car is moving at around 15mph does not occur at all. Sometimes it's a single bang, sometimes it's multiples, kind of like hitting a speed bump hard and having the axle hit the bump-stop.

Could anyone offer any ideas? Would it be something I could do or something that requires a shop(Given I have a novice level of skill)?

Thanks in advance!

Gatt

[vr4gasm]

Re: Need help diagnosing a new problem.

bushing in your lower control arm? broke exhaust hanger causing either the over the axel pipe to hit the bottom of your car or the muffler to smack around?

[Chris2088]

Re: Need help diagnosing a new problem.

Rear sway bar end link?

[Mogobs30th]

Re: Need help diagnosing a new problem.

could be a TQ arm, or something in the rear end as well.

[Gatt9]

Re: Need help diagnosing a new problem.

Thanks all for your replies!

[BallerMaro13]

Re: Need help diagnosing a new problem.

bushing in your lower control arm? broke exhaust hanger causing either the over the axel pipe to hit the bottom of your car or the muffler to smack around?

this would be my guess. sounds like your exhaust over the axle is bouncing around under hard takeoff.

but there's only one way to find out...get up under there and investigate.

[Gatt9]

Re: Need help diagnosing a new problem.

this would be my guess. sounds like your exhaust over the axle is bouncing around under hard takeoff.

but there's only one way to find out...get up under there and investigate.

I did head under there, was getting a little dark, looks like I have a hanger that's not connected to anything around the muffler, but couldn't see anything further up due to darkness and inexperience. There is another hanger right beside the one that's not connected that is holding the muffler up, so I'm pretty confused as to what's going on there atm.

At one point after I posted, I went back out, and I actually had a second "banging" sound coming from right under my center console hard enough to vibrate it, making me wonder if it could be something around the driveshaft?

[vr4gasm]

Re: Need help diagnosing a new problem.

get under there and shake the piss out of the exhaust up down side to side if nothing move on to the next thing.. underyour console may be tranny mount? they blow out quite often it seems like on these cars check that out

[BallerMaro13]

Re: Need help diagnosing a new problem.

yep, that, and while you're under there check out that d/s and make sure the joints are secure and nothing is hitting. if you have access to a lift or your buddies can help you get the car on ramps, check out everything from the y-pipe back and make sure everything is stable.

[cam98aro]

Re: Need help diagnosing a new problem.

I did head under there, was getting a little dark, looks like I have a hanger that's not connected to anything around the muffler, but couldn't see anything further up due to darkness and inexperience. There is another hanger right beside the one that's not connected that is holding the muffler up, so I'm pretty confused as to what's going on there atm.

At one point after I posted, I went back out, and I actually had a second "banging" sound coming from right under my center console hard enough to vibrate it, making me wonder if it could be something around the driveshaft?

that is normal

it sounds like your exhaust is banging on your driveshaft tunnel brace

it comes off with 4 bolts, either 13 or 15 cant remember.. take it off and go for a drive and see if your problem stops

[Opontee]

Re: Need help diagnosing a new problem.

that is normal

it sounds like your exhaust is banging on your driveshaft tunnel brace

it comes off with 4 bolts, either 13 or 15 cant remember.. take it off and go for a drive and see if your problem stops

Could be the tranny mount is broken, mine does this under hard acceleration.


but the noise from the right rear, mine does the same- it's not the exhust, spare tire and jack or the suspension. Or even the rubber stoppers for the hatch. I have changed all of this and it still persists. I'm just living with it, just rolled 239,000 miles, so I figure it's just a wore out car that gets 26 mpg.

[Gatt9]

Re: Need help diagnosing a new problem.

Hey, thanks guys!

I was actually starting to think Engine mount, tranny mount, or something with the driveshaft.

I've always had the hard shift problem from 1st to 2nd. I am getting noise only at the shift point from 1st to 2nd, or occasionally just after. I can avoid it by going through 1st with very light acceleration.

When I get the noise, to be more specific now that I've had time, I get one of three things...

1. Pulsing banging sound directly below console, very rhythemic.
2. Pulsing vibrating from under passenger seat.
3. Single bang from further back in the car, in the rear, sometimes followed by the first thing.

I'm going out tomorrow(Been working the last couple days), and I'm going to try and find my engine mounts and make sure they're intact.

Anyone have any suggestions on how I might see either the driveshaft tunnel brace or the tranny mounts without a lift?

Thanks again everyone!