Can makes noises when driving poping

[Creomod]

I have a 89 coupe. I have long tube headers and xpipe flowmasters dumped. I can see my shifter vibrating/moving and I can feel it in the steering wheel. It’s vibrating. I don’t think it’s the engine mounts I replaced them with stock ones couple years back. The trans mount I don’t think I did. Can bad rear control arm bushings cause this? I also have a cracked floor pan(passanger side) seat vibrates cuz I can see where it bolts is where the pan is cracked. I tack welded the crack and used seam sealer but I think that is where the popping is coming from. Exhaust to me sounds like it’s touching the brake lines. Am I going crazy lol? The vibrating is what gets to me. It might be a little on the tires as cause but no it’s gotten worse any ideas fellas. The tack welding no bueno on the floor pans or do I need to replace them?

 

[nickyb]

More info please.
Does it vibrate while driving only?
Does it vibrate while sitting still and revving it up?
Can you post a video?

 

[Habu135]

Ask your local muffler shop if you can put it up on their rack for an inspection, or if you don't want to kick a few bucks to him get under the car yourself. It probably isn't going to get better by itself, and it may be a safety issue.

 

[General karthief]

Flex cracks are kinda hard to stop even after welding, some have success drilling a small hole at each end of the crack then zip (weld) up the crack and holes, if you don't have sub-frame connectors that have the set supports grab some flat stock steel and cut and drill squares and bolt them under the car to spread the 'load'. We are talking about the rear seat bolts right?
The front seat bolts can tear out too.

 

[GearHeadGuy]

Shifter dance + wheel shake screams drivetrain movement, I'd say start with a fresh trans mount and check driveshaft U-joints, then verify pinion angle if ride height changed.

 

[Creomod]

Shifter dance + wheel shake screams drivetrain movement, I'd say start with a fresh trans mount and check driveshaft U-joints, then verify pinion angle if ride height changed.

I replaced the entire driveshaft I bought the sve one it came with new u joints. It does it I’m different speeds sometimes almost feels like the car is wobbling especially when I’m slowing down. No leaks there. At least I no I don’t have leaks in anywhere in the car yet.

 

[rednotch]

First off floor pan cracks, drill the ends of the cracks before welding them up or they will all ways come back, plate over the stitch weld with a small piece to reinforce it either on top or bottom. Almost every mustang I've owed where drag raced and had stress cracks near the seats. If it doesnt have subframe with a rear seat support bracket get or make one..

The noise does it do it, only moving, at idle, only at certain rooms / speeds?... U joints, suspension mounts, tires can all cause it. I had u joint do it only at certain rpm / speed. Chea parts store mounts stamped wrong do it at idle ect. As for shifter rattling streedas tri ax shifters all way do that for me in 3rd, for some reason its all ways been a streeda shifter.. They shift stops tend to rattle against the handle after a while, need to adjust them and add foam or tap on the ends of the stops.

 

[AeroCoupe]

Bad harmonic balancer?

 

[Creomod]

Bad harmonic balancer?

No

 

[Creomod]

I lifted car. I do notice some rear end seepage. Not sure if it’s comming from the cover or the pinion flange but I did have the pinion flange done anout 2 years back and I belive the cover had a lube locker seal. I belive it’s comming from pinion seal now if the vibration is from there does that mean my gears are ruined? I drive it daily. I remember lifting it few months back this just started . Or adding fluid would fix it of course got to fix the leak.

 

[Creomod]

First off floor pan cracks, drill the ends of the cracks before welding them up or they will all ways come back, plate over the stitch weld with a small piece to reinforce it either on top or bottom. Almost every mustang I've owed where drag raced and had stress cracks near the seats. If it doesnt have subframe with a rear seat support bracket get or make one..

The noise does it do it, only moving, at idle, only at certain rooms / speeds?... U joints, suspension mounts, tires can all cause it. I had u joint do it only at certain rpm / speed. Chea parts store mounts stamped wrong do it at idle ect. As for shifter rattling streedas tri ax shifters all way do that for me in 3rd, for some reason its all ways been a streeda shifter.. They shift stops tend to rattle against the handle after a while, need to adjust them and add foam or tap on the ends of the stops.

Dosent do it at idel but once I start rolling I hear it. I did lift car and I did have the brake lines touching the exhaust I know that was one of the noises it was soo annoying now I’m looking at the rear end and I see fluid leaking not bad but still it shouldn’t I had taken the rear end 2 years back and them redo the pinion flange not sure if that would cause vibrate but it had the stock fill hole and the sve cover had one should I fill on the stock or the sve cover

 

[Creomod]

Now I’d like to also add that when I meant the shifter was vibrating I meant the whole trans would shake over bumps I think more then usual now me getting under here I’m seeing rear end leaking I don’t think this was the problem but i know it is a major problem

 

[Creomod]

First off floor pan cracks, drill the ends of the cracks before welding them up or they will all ways come back, plate over the stitch weld with a small piece to reinforce it either on top or bottom. Almost every mustang I've owed where drag raced and had stress cracks near the seats. If it doesnt have subframe with a rear seat support bracket get or make one..

The noise does it do it, only moving, at idle, only at certain rooms / speeds?... U joints, suspension mounts, tires can all cause it. I had u joint do it only at certain rpm / speed. Chea parts store mounts stamped wrong do it at idle ect. As for shifter rattling streedas tri ax shifters all way do that for me in 3rd, for some reason its all ways been a streeda shifter.. They shift stops tend to rattle against the handle after a while, need to adjust them and add foam or tap on the ends of the stops.

When tou said suspension mounts what are you referring to? Struts & shocks or something else ?

 

[rednotch]

When tou said suspension mounts what are you referring to? Struts & shocks or something else ?

Bushings, spring isolators, torque box reinforcements with stock arms hitting the mounting hardware etc any thing that's mounted and moves.... I've seen way too much half ass on fox bodies in 25 years of playing with them. The one I just bought has alot of half ass done to it.

 

[General karthief]

A leak does not cause a vibration but a vibration can cause leaks.
Is the leak like dripping or a stream or is the area just wet (oil) and dirty?
I would fill till fluid runs out of stock fill hole, prolly easier to fill using the fill hole in the cover, take the stock plug out fill till it runs out.

 

[Creomod]

So I can fill thro the front but take off the fill plug in the back while I’m filling? Also it had a good amount of oil in it. I just noticed the leak it’s not under the car at least I never seen it I just happen to get under the car and saw the underside of the carrier is wet not a lot . I do have a bald tire on the back can a bad tire vibration cause leaking there ?

 

[General karthief]

Vibrations can cause all types of issues, a bald tire can cause vibrations, keep an eye on the wet spot of the diff maybe spray it down with some brake cleaner, and put some good rubber on it, see if that helps.d

 

[Creomod]

Yea I might have to bite the billet and get a tire soon