Weird Vibration Sound While Driving

[BlackIce]

Ok i recently got my exhaust installed and its been perfect! no problems. now wen i accelerate or move slowly (while the car is NOT in gear) i hear a really strange vibration coming from the rear passenger side! it cant be my exhaust cuz its no where near that area, i stopped the car and looked to see if anything was lose in the trunk and everthing was snug. started driving again and it was still there! i looked under the car and nothing looked strange, everything was secure! i have nothing in my car, 100% empty except for my change beside my shifter. i noticed this sound last night after dropping my friends off from a night out.

has this happened to anyone before? can someone please help cuz its getting annoying and im really concerned!

PS. i only hear this sound wen i go slower then 40 kph

[Donutz]

'Strange vibration' is somewhat vague. Can you give more detail about the vibration?

[Woodman316]

Maybe the tires, is time to rotate them. Check if the sound moves with the rotation.

[BlackIce]

'Strange vibration' is somewhat vague. Can you give more detail about the vibration?

its like a vibration... i donno, its a slow vibration if that helps... u hear it more then feel it!

[Noisy Crow]

Something hanging out catching air?

[BlackIce]

Something hanging out catching air?

dont think so.... it completely stops once i hit 40 or so and from 20 kph to 40 kph the vibration doesnt pick up, it stays constant almost, only wen it starts up it goes from slow to fast but once i reach like 20 kph it stays the same till 40 then its gone! and then wen i let go of the gas and my RPMs are around 2,500 and i use the engine to slow down, the exhaust makes the deep sound that it does and the vibration on the other side of the car comes back no matter wat the speed is (but not always, only sometimes).

sorry if what im typing isnt making sense, im really tired and i just want to figure out wats wrong!

[ender78]

I am having the same problem, and feeling stupid when trying to explain it to my mechanic. I have to leave for work but will add more later. Tires are NOT the problem as this problem was there on my winter tires/rims as well. I am taking my car in for alignment as it also pulls a little to the left.

[toronto]

Same problem here, 2004 Mazda3 GS hatchback, 100K+

I would describe it as a rattle from somewhere below the car and behind the engine compartment. It's only happening when driving at low speed after a cold start for about 5-10 minutes. if I speed up or drive longer, the rattle seems to be gone.

It's very consistent, but I haven't considered it a big enough problem to worry about it.

[toronto]

Just to add, I have an automatic, unlike the OP. And it's definitely not the tires.

[warlord]

You had an exhaust installed ? Go under the car and check all the heat shielding. It's thin metal that will vibrate if it's been moved or disturbed in any way. I know you said the noise is on the oppposite side of the exhaust but it's worth a look.

[Donutz]

Same problem here, 2004 Mazda3 GS hatchback, 100K+

I would describe it as a rattle from somewhere below the car and behind the engine compartment. It's only happening when driving at low speed after a cold start for about 5-10 minutes. if I speed up or drive longer, the rattle seems to be gone.

It's very consistent, but I haven't considered it a big enough problem to worry about it.

List your mods and recent service / installs so we can give more advice.

[bman13]

bent wheel?

[toronto]

Jason, the car is pure stock - nothing was done to it. Don't know whey the rattle is only there at low speed and only for 5-10 minutes. Maybe I cannot hear it at higher speeds?

I'll check the heat shield and the plastic cowling (splash shield) under the engine, it appears loose, maybe missing a screw or two. Instead of taking that plastic cover off when changing oil, some genius mechanic cut a hole under the oil drain :( Saves a few minutes, I guess.

[BlueJoe]

This is the exact problem i had 2 weeks ago, i thought it was my exhaust.

Turned out it was the engine mount that cost me $280 to replace.

Today I found out my other 2 mounts broke aswell, and I had them replaced, adding up to a steep bill.

:bang

[toronto]

Update: Went to Street Performance, had Jimmy check it out.

Jimmy says it's an engine mount. Will have it replaced next week.